Using 3 d_analyst

ArcGIS®

9Using ArcGIS® 3D Analyst™

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The information contained in this document is subject to change without notice.

DATA CREDITSExercise 1: Death Valley image data courtesy of National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL)/Caltech.

Exercise 2: San Gabriel Basin data courtesy of the San Gabriel Basin Water Quality Authority.

Exercise 3: Belarus CS137 soil contamination and thyroid cancer data courtesy of the International Sakharov Environmental University.

Exercise 4: Hidden River Cave data courtesy of the American Cave Conservation Association.

Exercise 5: Elevation and image data courtesy of MassGIS, Commonwealth of Massachusetts Executive Office of Environmental Affairs.Exercise 6: Las Vegas Millennium Mosaic (Year 2000 Landsat) and QuickBird images data courtesy of DigitalGlobe.Exercise 7: Ozone concentration raster derived from data courtesy of the California Air Resources Board, Southern California Millennium Mosaic (Year2000 Landsat) image courtesy of DigitalGlobe, Angelus Oaks imagery courtesy of AirPhoto USA, Southwestern U.S. elevation data derived from U.S.

National Elevation Data courtesy of the U.S. Geological Survey.

CONTRIBUTING WRITERSSteve Bratt, Bob Booth

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acquire greater than RESTRICTED/LIMITED RIGHTS. At a minimum, use, duplication, or disclosure by the U.S. Government is subject to restrictions as

set forth in FAR §52.227-14 Alternates I, II, and III (JUN 1987); FAR §52.227-19 (JUN 1987) and/or FAR §12.211/12.212 (Commercial Technical Data/

Computer Software); and DFARS §252.227-7015 (NOV 1995) (Technical Data) and/or DFARS §227.7202 (Computer Software), as applicable. Contractor/

Manufacturer is ESRI, 380 New York Street, Redlands, CA 92373-8100, USA.

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Portions of this software are under license from GeoFusion, Inc. Copyright © 2002, GeoFusion, Inc. All rights reserved.

Other companies and products mentioned herein are trademarks or registered trademarks of their respective trademark owners.

iii

Contents Using ArcGIS 3D Analyst 1

1 Introducing ArcGIS 3D Analyst 3What can you do with 3D Analyst? 5Tips on learning 3D Analyst 8

2 Quick-start tutorial 9Copying the tutorial data 10Exercise 1: Draping an image over a terrain surface 12Exercise 2: Visualizing contamination in an aquifer 22Exercise 3: Visualizing soil contamination and thyroid cancer rates 27Exercise 4: Building a TIN to represent terrain 37Exercise 5: Working with animations in ArcScene 51Exercise 6: ArcGlobe basics 58Exercise 7: ArcGlobe layer classification 68

3 Creating surface models 77What are surfaces and surface models? 78Creating raster surfaces from points 80Interpolating a raster surface 89Kriging interpolation 93Saving all rasters in a specified location 96Setting an analysis mask 97Setting the coordinate system for your analysis results 98Setting the output extent 99Setting the output cell size 100Creating TIN surfaces from vector data 101Building a TIN 103Creating a TIN from a raster 105Creating a raster from a TIN 106

iv USING ARCGIS 3D ANALYST

124 Managing 3D data 107

ArcCatalog basics 108Previewing 3D data 111The camera, the observer, and the target 113Displaying 2D data in 3D 117Starting ArcScene from ArcCatalog 121Creating a new 3D feature class 122

5 Displaying surfaces 123Displaying raster surfaces in 3D 124Displaying raster surfaces 125Symbolizing areas with unknown values 132Displaying TIN surfaces 133Making a layer transparent 143Shading a layer 144

6 Analyzing surfaces 145Querying surface values 146Understanding the shape of a surface 148Calculating slope 150Deriving slope from a raster surface 151Calculating aspect 152Deriving aspect from a raster surface 153Mapping contours 154Deriving contour lines from a surface 156Analyzing visibility 158Creating a line of sight 160Deriving a viewshed 161Computing hillshade 162Deriving hillshade from a surface 163Shading 3D surfaces in a scene 165Determining height along a profile 166

CONTENTS v

Finding the steepest path 167Calculating area and volume 168Reclassifying data 169Reclassifying your data 170Converting rasters and TINs to vector data 174Converting surfaces to vector data 175Creating 3D features 177

7 3D visualization 181Creating a new scene 182Adding 3D graphics to a scene 184Feature data and 3D 185Defining the z-values for a layer 186Raster data and 3D 193Defining the 3D properties of a raster layer 194Converting z-units to x,y units 196Offsetting the heights in a layer 197Controlling when a layer is rendered 198Using the 3D Effects toolbar 200Using face culling to control the way layers are drawn 202Changing a layer’s drawing priority 203Viewing a scene from different angles 204Managing scene viewers 205Changing the viewer settings 207Navigating through a scene using the Fly tool 210Setting bookmarks 211Viewing in Stereo mode 212Setting the properties of a scene 216Changing the vertical exaggeration 217Using animated rotation 218Changing the background color 220

vi USING ARCGIS 3D ANALYST

Changing the scene illumination 222Changing the scene extent 225Changing the scene coordinate system 227Selecting features in a scene 229Exporting a scene 233Printing a scene 235

8 Animation 2373D animation 238Creating animations 240Capturing perspective views 241Recording and playing back animation tracks 242Creating keyframes 243Making group animations 246Making animations from paths 247Using the Animation Manager 249Timing properties in the Animation Manager 251Saving an animation 252Sharing animations: Loading an ArcScene or ArcGlobe Animation file 254

9 3D symbology 257What is a 3D symbol? 258Using 3D symbols 260Using 3D styles 261Making 3D symbols 263The 3D Symbol Property Editor 264Altering the placement of a 3D symbol 265Offsetting a 3D symbol 266Scaling the size of 3D symbols 268Using 3D styles to assign symbology 270Symbolizing points with 3D symbols 272Symbolizing lines with 3D symbols 275

CONTENTS vii

Symbolizing polygon fills with 3D symbols 278Saving the current styles 280Organizing 3D style contents 281Creating and modifying 3D symbols and elements 283

10 3D graphics and text 285The 3D Graphics toolbar 2863D text 289Changing properties of selected graphic elements 290Changing defaults for the way graphics appear 291Graphics layers 293

ArcGlobe 295

11 Introducing ArcGlobe 297What can you do with ArcGlobe? 298

12 Using ArcGlobe 301Types of data you can use with ArcGlobe 302Default layers 303User-defined default layers 304System default layers 305Creating a new globe 306The ArcGlobe document 308The ArcGlobe table of contents and layer types 309Layer drawing order 312Navigating in ArcGlobe 313Using the camera target to simplify navigation 316Zooming to a layer’s extent 318Using the Walk tool 319Globe layer properties 320

viii USING ARCGIS 3D ANALYST

Setting the visibility range of a layer 321Reclassifying a layer 322Draped layers 323What is a floating layer? 324Layer cache properties 326Globe display layer properties 328Rasterizing features 329Feature properties 330Scaling 3D symbols 331See-through position 332Globe properties 333Background options 335Illumination options 337ArcGlobe application-level options 340Setting the default view at full extent 341Application-level cache options 342Disk caches 343Level of detail 344Compression options 345Lossy spatial compression 346Elevation compression 347Table of contents options 348What is caching and how do I use it? 349

Glossary 353

Index 363

Section 1

Using ArcGIS 3D Analyst

IN THIS CHAPTER

3

Introducing ArcGIS 3D Analyst 1• What can you do with 3D Ana-

lyst?

• Tips on learning 3D Analyst

Welcome to ESRI® ArcGIS® 3D Analyst™, the three-dimensional (3D)visualization and analysis extension. 3D Analyst adds two specialized 3Dviewing applications, ArcScene™ and ArcGlobe™, that extend thecapabilities of ArcGIS Desktop and adds additional capabilities toArcCatalog™ and ArcMap™.

ArcScene lets you make perspective view scenes in which you cannavigate and interact with your geographic information system (GIS) data.You can drape raster and vector data over surfaces and extrude featuresfrom vector data sources to create lines, walls, and solids. You can also use3D Analyst tools in ArcScene to create and analyze surfaces.

ArcGlobe provides real-time pan and zoom of very large (hundreds ofgigabytes) of 3D raster, terrain, and vector datasets with no perceivablehesitation on standard computer hardware. This has been achieved by theintroduction of a new approach for indexing and quickly retrieving data.ArcGlobe is discussed in detail in Section 2 of this book.

ArcCatalog is extended by 3D Analyst so you can manage 3D data andcreate layers with 3D viewing properties. You can preview scenes and datain 3D in ArcCatalog using the same navigation tools you use in ArcScene.

ArcMap is extended by 3D Analyst so you can create new surfaces fromyour GIS data as well as analyze surfaces, query attribute values at alocation on a surface, and analyze the visibility of parts of a surface from

4 USING ARCGIS 3D ANALYST

different locations. You can also determine the surface areaand the volume above or below a surface and createprofiles along a 3D line on a surface.

3D Analyst also lets you create 3D features from existingtwo-dimensional (2D) GIS data—or you can digitize new3D vector features and graphics in ArcMap using a surfaceto provide the z-values.

INTRODUCING ARCGIS 3D ANALYST 5

What can you do with 3D Analyst?

3D Analyst provides you tools in ArcScene and ArcGlobe foranalysis and visualization of 3D data. It also extends ArcCatalogand ArcMap so you can more effectively manage your 3D GISdata and do 3D analysis and 3D feature editing in ArcMap.

You can change the properties of 3D layers to use shading ortransparency, and you can change the properties of a 3D scene to

3D view of raster and vector data

3D view of utility poles and power lines

Viewing a scene from another perspective with another viewer

What can you do with ArcScene?

ArcScene provides the interface for viewing multiple layers of 3Ddata for visualizing data, creating surfaces, and analyzingsurfaces.

Visualizing data

3D Analyst lets you drape images or vector data over surfacesand extrude vector features from a surface. You can view a scenefrom multiple viewpoints using different viewers.


set the vertical exaggeration of terrain, the coordinate system andextent for the scene, and the illumination of the scene.

Creating surfaces

The 3D Analyst tools that are available in both ArcScene andArcMap allow you to create surface models from your GIS data.You can interpolate raster surfaces and create or add features totriangulated irregular network (TIN) surfaces.

Exaggerating the vertical dimension of a scene

You can derive new rasters of slope and aspect from surfacemodels, create contours, and find the steepest paths on a surface.

TIN and raster surfaces

Slope and aspect rendering of surfaces

Contours and steepest paths

Analyzing surfaces

3D Analyst lets you interactively query the values in a rastersurface and the elevation, slope, and aspect of TINs.

You can also analyze the visibility between different locations ona surface; create rasters that show the level of illumination of asurface (given a sun altitude and direction); and reclassify rasterdata for display, analysis, or feature extraction purposes.

What can you do with ArcGlobe?

See Section 2, ArcGlobe, for detailed information on ArcGlobefunctionality.

INTRODUCING ARCGIS 3D ANALYST 7

What can you do with ArcMap?

Line of sight created on a TIN in ArcMap, displayed in ArcScene

3D line graphic created on a raster in ArcMap and a profile graph ofthe line.

ArcCatalog lets you browse your data and create and preview layers in3D.

Navigate the 3D preview; identify features, raster cells, and TINtriangles.

What can you do with ArcCatalog?

Installing 3D Analyst lets you add the 3D Analyst toolbar toArcMap, so you can do all of the surface creation and analysistasks in ArcMap that you can do in ArcScene. It also addsseveral tools that only operate in ArcMap: a tool that lets you

find lines of sight on a surface, three tools for digitizing 3Dfeatures and graphics using z-values from a surface, and a toolthat lets you create graphs of the profile (change in elevationover distance) along a 3D line.

ArcCatalog is the ArcGIS application for managing your GIS data.3D Analyst lets you preview and navigate your 3D data. You cancreate GIS data layers and define their 3D viewing properties.

You can also preview the scenes you’ve created in ArcScene. Youcan create metadata for your 3D GIS data including 3D thumbnailsof scenes and data. You can create empty 3D feature classes orshapefiles in ArcCatalog that can then be populated by digitizing3D features in ArcMap.


Tips on learning 3D Analyst

If you’re new to GIS, take some time to familiarize yourself withArcMap and ArcCatalog. The books Using ArcMap and UsingArcCatalog contain tutorials to show you how to make maps andmanage GIS data.

Begin learning to use 3D Analyst and ArcGlobe in Chapter 2,‘Quick-start tutorial’, in this book. You’ll learn how to open a 3Dscene, add and query data in a 3D scene, create surfaces, and useArcScene with ArcCatalog and ArcMap. You’ll also learn how toopen a globe, add data in a globe, and navigate in ArcGlobe. 3DAnalyst and ArcGlobe come with the data used in this tutorial, soyou can follow along step by step at your computer. You can alsoread the tutorial without using your computer.

Finding answers to questions

Like most people, your goal is to complete your task whileinvesting a minimum amount of time and effort in learning how touse the software. You want intuitive, easy-to-use software thatgives you immediate results without having to read pages andpages of documentation. However, when you do have a question,you want the answer quickly so that you can complete your task.That’s what this book is all about—getting you the answers youneed, when you need them.

The first section in this book describes how to display your datain three dimensions, to create new surfaces from existing data,and to analyze three-dimensional surfaces. Section 2 describeshow to add and display your data in ArcGlobe and how tonavigate and interact with it. Although you can read this bookfrom start to finish, you’ll likely use it more as a reference. Whenyou want to know how to do a particular task, such as addingshading to a surface or switching the navigation mode from spaceflight mode to atmospheric flight mode, just look it up in the tableof contents or the index. You’ll find a concise, step-by-stepdescription of how to complete the task. Some chapters also

include detailed information that you can read if you want to learnmore about the concepts behind the tasks. You can also refer tothe glossary in this book if you come across any unfamiliar terms.

Getting help on your computer

In addition to this book, use the ArcGIS Desktop Help system tolearn how to use 3D Analyst and ArcGlobe. To learn how to useHelp, see Using ArcMap.

Contacting ESRI

If you need to contact ESRI for technical support, refer to‘Contacting Technical Support’ in the ‘Getting more help’ sectionof the ArcGIS Desktop Help system. You can also visit ESRI onthe Web at www.esri.com and support.esri.com for moreinformation on 3D Analyst, ArcGlobe, and ArcGIS.

ESRI education solutions

ESRI provides educational opportunities related to geographicinformation science, GIS applications, and technology. You canchoose among instructor-led courses, Web-based courses, andself-study workbooks to find educational solutions that fit yourlearning style. For more information go towww.esri.com/education.

IN THIS CHAPTER

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Quick-start tutorial 2• Copying the tutorial data

• Exercise 1: Draping an image overa terrain surface

• Exercise 2: Visualizingcontamination in an aquifer

• Exercise 3: Visualizing soilcontamination and thyroid cancerrates

• Exercise 4: Building a TIN torepresent terrain

• Exercise 5: Working withanimations in ArcScene

• Exercise 6: ArcGlobe basics

• Exercise 7: ArcGlobe layer classifi-cation

The best way to learn 3D Analyst is to use it. In the exercises in thistutorial, you will:

• Use ArcCatalog to find and preview 3D data.

• Add data to ArcScene.

• Set 3D properties for viewing data.

• Create new 3D feature data from 2D features and surfaces.

• Create new raster surface data from point data.

• Build a TIN surface from existing feature data.

• Make animations.

• Learn how to use ArcGlobe and manage its data content.

In order to use this tutorial, you need to have the 3D Analyst extensionand ArcGIS installed and have the tutorial data installed on a local orshared network drive on your system. Ask your system administrator forthe correct path to the tutorial data if you do not find it at the defaultinstallation path specified in the tutorial.


Copying the tutorial data

First you will copy the tutorial data to a local drive. You willuse ArcCatalog to browse to and copy the data.

1. Click Start, point to Programs, point to ArcGIS, and clickArcCatalog.

3. Right-click the 3DAnalyst folder and click Copy.

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ArcCatalog lets you find and manage your data. The leftside of the ArcCatalog window is called the Catalogtree; it gives you a bird’s-eye view of how your data isorganized and provides a hierarchical view of thegeographic data in your folders. The right side of theCatalog window shows the contents of the selectedbranch of the Catalog tree.

2. Click in the Location combo box and type the path to the\arcgis\ArcTutor folder on the drive where the tutorialdata is installed. Press Enter.

The ArcTutor folder is now the selected branch of theCatalog tree. You can see its contents in the Contentstab.

4. Right-click the local drive where you want to place thetutorial data and click Paste.

The folder is copied to your local drive. Now you willmake a folder connection to the 3DAnalyst folder in theCatalog tree.

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QUICK-START TUTORIAL 11

5. Click the 3DAnalyst folder on your local drive and dragit onto the top-level node, Catalog, of the Catalog tree.

There is now a folder connection in the Catalog for yourlocal copy of the tutorial data.

In the graphics illustrating this tutorial, the ArcCatalogoption to use a special folder icon for folders containing GISdata is turned on. That is why the folder GISdata, in thegraphic above, looks different from the other folders. Youcan turn this option on in ArcCatalog, in the Options dialogbox, on the General tab. ArcCatalog works faster when thisoption is turned off, so it is off by default.

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Viewing a remotely sensed image draped over a terrainsurface can often lead to greater understanding of thepatterns in the image and how they relate to the shape ofthe earth’s surface.

Imagine that you’re a geologist studying Death Valley,California. You have collected a TIN that shows the terrainand a satellite radar image that shows the roughness of theland surface. The image is highly informative, but you canadd a dimension to your understanding by draping the imageover the terrain surface. Death Valley image data wassupplied courtesy of NASA/JPL/Caltech.

Turning on the 3D Analyst extension

You will need to enable the 3D Analyst extension.

1. Click Tools and click Extensions.

Exercise 1: Draping an image over a terrain surface

2. Check 3D Analyst.

3 Click Close.

Previewing 3D data in ArcCatalog

Before you drape the image, you will browse to the terraindata and preview it in ArcCatalog.

1. Navigate to the 3DAnalyst folder connection in theCatalog tree.

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2. Double-click 3DAnalyst.

3. Double-click Exercise1.

5. Click the Preview tab. You can preview your GIS data inArcCatalog. With 3D Analyst installed, you can alsopreview some data in three dimensions.

6. Click the Preview dropdown arrow and click 3D View.

You see a folder called Data and a TIN layer calledDeath Valley Terrain.

A layer is a shortcut to geographic data. It also storesinformation about how the geographic data should bedrawn on a map or in a 3D scene.

4. Click Death Valley Terrain.

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7. Right-click above the preview window and click 3DView Tools.

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The preview becomes a 3D preview, and a new set oftools appears on the 3D View Tools toolbar.

The data rotates around its center. The Navigate toolalso allows you to zoom in and out and pan across thedata, depending on the mouse button that you click whiledragging in the 3D preview.

9. Right-click on the 3D preview and drag down.

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The Navigate tool is active when you first preview datain 3D. You can see the names of tools by hovering thepointer over the tool.

The Navigate tool allows you to rotate 3D data andchange the apparent viewer height by clicking anddragging left and right and up and down, respectively, inthe 3D preview.

8. Click on the 3D preview and drag to the right. The pointer changes to the Zoom In/Out pointer, and theview zooms in to the data.

10. Click the middle button—or both the right and leftbuttons if you have a two-button mouse—and drag tothe right.

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Navigate

Zoom In/Out Pan


The pointer changes to the Pan pointer, and the viewpans across the data.

11. Click the Identify button and click on the TIN.

The view returns to the full extent of the data.

The Identify Results window shows you the elevation,slope, and aspect of the surface at the point you clicked.

12. Close the Identify Results window.

13. Click the Full Extent button.

Now you’ve examined the surface data and begun to learnhow to navigate in 3D. The next step is to start ArcSceneand add your radar image to a new scene.

Starting ArcScene and adding data

ArcScene is the 3D viewer for 3D Analyst. Although youcan preview 3D data in ArcCatalog, ArcScene allows youto build up complex scenes with multiple sources of data.

1. Click the ArcScene button on the 3D View Tools toolbar.R

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Identify

ArcScene


ArcScene starts. Note that many of the tools on theArcScene Standard toolbar are the same as the 3Dnavigation tools that you see in ArcCatalog.

3. Click the Add Data button on the ArcScene Standardtoolbar.

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4. Navigate to the Data folder for Exercise1.

2. Click the Death Valley Terrain layer in the Catalog treeand drag it onto the right-hand side of the ArcScenewindow, then release the mouse button.

The TIN is drawn in the new scene.

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5. Click dvim3.TIF.

6. Click Add.

7. Uncheck the Death Valley Terrain layer.

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The image is added to the scene.

The image is drawn on a plane, with a base elevationvalue of zero. You can see it above the Death Valleyterrain surface where the terrain is below 0 meterselevation (sea level); it is hidden by the terrain surfaceeverywhere else.

Now you can see the whole image. The black areas areparts of the image that contain no data and are a resultof previous processing to fit the image to the terrain.

You have added the image to the scene. Now you willchange the properties of the image layer so that the imagewill be draped over the terrain surface.

Draping the image

While the surface texture information shown in the image isa great source of information about the terrain, somerelationships between the surface texture and the shape ofthe terrain will be apparent when you drape the image overthe terrain surface. In ArcScene, you can drape a layer—containing a grid, image, or 2D features—over a surface (agrid or TIN) by assigning the base heights of the layer fromthe surface.

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1. Right-click dvim3.TIF in the ArcScene table of contentsand click Properties.

3. Click the option to Obtain heights for layer from surface.

Because the TIN is the only surface model in the scene,it appears in the surface dropdown list.

4. Click OK.

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The layer Properties dialog box appears. You can changehow a layer is drawn on a map or in a scene by settingits properties.

2. Click the Base Heights tab. The image is draped over the terrain surface.

Now you will be able to navigate around the image and seethe relationship between surface texture, as shown by theimage colors, and the shape of the terrain.

Exploring the image

You will use the navigation tools on the ArcScene Toolstoolbar to explore the draped image.

1. Click the Zoom in button.

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2. Click and drag a rectangle around the middle of theimage.

4. Click on the scene and slowly drag up and to the left.

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The scene zooms to the middle part of the image.

3. Click the Navigate button.

The scene rotates, and the view angle lowers, so it looksas though you are looking down the valley, past thehigher land on the left side of the scene.

Elevated, rocky area

FloodplainAlluvial fan


The Scene Properties dialog box lets you set propertiesthat are shared by all of the layers in the scene. Theseinclude the vertical exaggeration, the background (sky)color, the coordinate system and extent of the data, andthe way that the scene is illuminated (the position of thelight source relative to the surface).

2. Click the General tab.

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3. Type “2” in the Vertical Exaggeration combo box.

4. Click OK.

The apparent height of the terrain is now doubled.

The elevated land is visibly rougher terrain than the flatvalley bottom. The surface texture—and therefore thecolor, in the radar image—of this rocky area is differentthan the fine sediment of the floodplain—the yellow andblack region in the valley bottom. The rocky area is alsoa different texture from the gently sloping alluvial fanthat runs past it, down onto the valley floor.

Draping the radar image over the terrain surface allows youto see the relationship between the general shape of theland surface and the texture of the rocks and sediment thatmake up the surface.

Exaggerating the terrain

The valley is a broad area, relative to the height of theterrain, even though the mountains at the edge of the sceneare more than 2,000 meters above the valley floor. In orderto enhance the sense of depth in the scene, and to bring outsubtle features in the terrain, you will exaggerate the heightof the terrain.

1. Right-click Scene layers in the table of contents andclick Scene Properties.

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You can now clearly see how the alluvial fan spreads outonto the valley floor, between the larger rocky area atthe center of the scene and the smaller rocky area in theforeground at the left side of the scene.

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1. Click File and click Save As.

You have added depth to the radar image, explored thegeneral relationship between the data in the image and theterrain data, and enhanced the scene so that you canperceive more subtle variations in the terrain.

Now that you’ve built the scene, you will save it so that youcan explore it later if you choose.

Saving the scene

Scenes, also called Scene Documents, are like maps. Theycontain information about how the layers that are in thescene should be rendered and where the data is located.

2. Navigate to the Exercise1 folder.

3. Type “Deathvalley”.

4. Click Save.

The scene will now be available for you to open later.

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Exercise 2: Visualizing contamination in an aquifer

Imagine that you work for a water district. The district isaware of some areas where volatile organic compounds(VOCs) have leaked over the years. Scientists from yourdepartment have mapped some plumes of VOCs in theaquifer, and you want to create a 3D scene to help officialsand the public visualize the extent of the problem.

Some of the data for the scene has already been assembledin the Groundwater scene. You will modify the scene tobetter communicate the problem.

VOC data was supplied courtesy of the San Gabriel BasinWater Quality Authority.

Opening the Groundwater scene document

This scene document contains a TIN that shows the shapeof the contaminant plume, a raster that shows theconcentration of the contaminant, and two shapefiles thatshow the locations of parcels and wells. You will drape theconcentration raster over the plume TIN, extrude thebuilding features and change their color, and extrude thewell features so that the wells that are most endangered bythe contamination may be more easily recognized.

1. In ArcScene, click File, then click Open.

3. Click Groundwater.sxd.

2. Navigate to the Exercise2 folder.

4. Click Open.

The Groundwater scene opens. You can see the fourlayers in the table of contents.

Showing the volume and intensity ofcontamination

You’ll drape the raster of VOC concentration over the TINof the contaminant plume surface to show the volume andintensity of contamination in the aquifer.

1. Right-click congrd and click Properties.

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2. Click the Base Heights tab.

5. Click the Color Ramp dropdown arrow and click a redcolor ramp for the raster.

6. Click OK.

7. In the table of contents, uncheck plume.

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3. Click the dropdown arrow and click plume to get theheights from the plume TIN.

Now you will change the symbology of the raster toshow the intensity of the contamination.

4. Click the Symbology tab.

Now it is possible to see the shape of the plume and itsintensity in 3D.

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Showing the relationship of the plume to wells

You can see that some of the wells are within the area ofthe plume. However, it is difficult to see which wells aremost seriously affected because the contamination is morewidespread but less concentrated at greater depths.

You will extrude the well features based on their depthattribute in order to see which wells intersect the plume.

1. Right-click wells and click Properties.

You will display the well points as vertical lines equal tothe depth of the well. This information is stored in theWELL_DPTH field.

4. Click WELL_DPTH.

2. Click the Extrusion tab.

3. Click the Calculate Extrusion Expression button.

5. Click OK.

6. Click the dropdown arrow to apply the extrusionexpression by adding it to each feature’s base height.The well depths are expressed as negative values, sothey’ll be extruded downward.

7. Click OK.

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You can see the places where the wells intersect, or areclose to, the plume. Now you will modify the scene to showthe priority of various facilities that have been targeted forcleanup.

Showing the facilities with a high cleanup priority

Analysts in your department have ranked the facilitiesaccording to the urgency of a cleanup at each location.You’ll extrude the facilities into 3D columns and color codethem to emphasize those with a higher priority for cleanup.

1. Right-click facility and click Properties.


5. Type “* 100”.


4. Click PRIORITY1.

6. Click OK.

The expression you created appears in the Extrusionvalue or expression box.

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8. Click Quantities.

9. Click the Value dropdown list and click PRIORITY1.

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11. Click the Save button.

10. Click OK.

The facilities are now extruded in proportion to theirpriority score. The scene now shows the shape andintensity of the contamination, the wells in relationship tothe plume, and the facilities that need to be cleaned upin order to prevent further pollution of the groundwater.

Now you’ll save your changes to the scene.

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Exercise 3: Visualizing soil contamination and thyroid cancer rates

In 1986, after the catastrophic accident at the Chernobylnuclear power plant in Ukraine, a large amount ofradioactive dust fell on Belarus. Since then, scientists havestudied the aftermath of the accident. One tool for exploringthe data is 3D visualization. In this exercise, you will createtwo surfaces from point data collected in Belarus. One setof points contains measurements of soil CS137concentrations. CS137 is one of several radioactive isotopesreleased by the accident. The other set of points shows therates of thyroid cancer, aggregated by district, with thesample point placed near the district centers.

The CS137 contamination and thyroid cancer data wassupplied courtesy of the International SakharovEnvironmental University.

Viewing the point data

First, you will open the Chernobyl scene and view the pointdata.

1. Click File and click Open.

The CS137 soil measurements are shown with smallpoint symbols, using a graduated color ramp to show theintensity of the contamination. The districts’ thyroidcancer rates are shown with larger symbols, using adifferent color ramp.

Creating 3D point features

The soil CS137 samples are 2D points with some attributes.One way to view 2D points in 3D is by setting an extrusionexpression, or a base height. You can also incorporate az-value into a feature’s geometry to allow it to be directlyviewed in 3D without the need to set a base height from asurface or an attribute.

First, you’ll add the 3D Analyst toolbar to ArcScene.

2. Navigate to Exercise3 and click Chernobyl.

3. Click Open.

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1. Click View, point to Toolbars, and click 3D Analyst. 3. Click the Input Features dropdown list and clickSubsample_1994_CS137.

The 3D Analyst toolbar in ArcScene contains several 3Danalysis and data conversion tools. The ArcMap3D Analyst toolbar contains the same tools, plus severaladditional tools that you can use in ArcMap.

Now you will create 3D point features from the soilCS137 points.

2. Click 3D Analyst, point to Convert, and click Features to3D.

4. Click the Input Feature Attribute button, then click theInput Feature Attribute dropdown list and clickCS137_CI_K.

5. Change the output feature name to CS137_3D.

6. Click OK.

The features are converted to 3D point features. However,they still seem to be resting on a flat plane because theCS137 concentration values range from 0 to 208.68, whichis small relative to the horizontal extent of the data.

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Increasing the vertical exaggeration

You will exaggerate the scene to show the new points withtheir height embedded in the feature geometry.

1. Click View and click Scene Properties.

3. Click Calculate From Extent.

4. Click OK.


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Now that you can see the new 3D points in the scene,you can turn off the original CS137 sample point layer.

6. Uncheck the box in the table of contents besideSubsample_1994_CS137 and click the minus sign besidethe box to hide the classification.

Extruding columns

Viewing points in 3D space is one way to investigate data.Another way is to extrude points into columns. You willextrude the thyroid cancer points into columns to comparethem to the contamination data.

1. Right-click ThyroidCancerRates and click Properties.

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2. Click the Extrusion tab. 6. Click OK on the Expression Builder dialog box.

7. Click OK on the Layer Properties dialog box.

Now the district centroid points are shown with columnsproportionate to the thyroid cancer rates. If you navigatethe scene you will see that the areas with the highestcontamination levels also tend to have high thyroidcancer rates, although there are areas with lower CS137contamination levels that also have high cancer rates.

Creating a surface from point sample data

You know what the soil concentrations of CS137 are at thesample point locations, but you do not know what they areat the locations between sample points. One way to derivethe information for locations between sample points is tointerpolate a raster surface from the point data. There aremany ways to interpolate such surfaces, which result indifferent models of varying accuracy. In this exercise youwill interpolate a surface from the samples using theInverse Distance Weighted (IDW) interpolation technique.IDW interpolation calculates a value for each cell in theoutput raster from the values of the data points, with closerpoints given more influence and distant points lessinfluence.

1. Click 3D Analyst, point to Interpolate to Raster, and clickInverse Distance Weighted.


4. Click INCID1000 (the rate of cases per 1,000 persons).

Because the z-values of the phenomena that you arecomparing have different ranges, you will multiply thecancer rate by 100 to bring the values into a rangesimilar to that of the CS137 measurements.

5. Type “* 100”.

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2. Click the Input points dropdown list and clickSubsample_1994_CS137.

6. Click Save.

7. Click OK.

3. Click the Z value field dropdown list and clickCS137_CI_K.

4. Click the Browse button.

5. Navigate to the Exercise3 folder and type“CS137_IDW” in the Name field.

ArcScene interpolates the surface and adds it to the scene.

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Viewing the interpolated surface

Now that the surface has been added to the scene, you cansee that there are two areas with very high concentrationsof CS137. You will view the surface in perspective, with anew color ramp, to better see its shape.

1. Right-click CS137_IDW and click Properties.


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3. Click the Color Ramp dropdown arrow and click a newcolor ramp.

5. Click Obtain heights for layer from surface.

6. Click OK.

7. Uncheck CS137_3D in the table of contents.

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Now you can see the interpolated surface of CS137contamination, along with the thyroid cancer rate data.

3. Double-click INCID1000 in the Fields list.

Next, you will select the province centers with thehighest rates of thyroid cancer.

Selecting features by an attribute

Sometimes it is important to focus on a specific set of dataor specific features. You can select features in a scene bytheir location, by their attributes, or by clicking them withthe Select Features tool. You will select the provincecenters by attribute to find the locations with the highestrates.

1. Click Selection and click Select By Attributes.

2. Click the Layer dropdown arrow and clickThyroidCancerRates.

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4. Click the >= button.

They are drawn in light blue to indicate that they areselected.

Viewing the attributes of features

You will investigate attributes of the selected locations andfind out how many cases of thyroid cancer occurred inthese districts.

1. Right-click ThyroidCancerRates and click OpenAttribute Table.

5. Type “0.5”.

6. Check the selection expression you’ve built.

7. Click Apply.

8. Click Close.

The province centers with thyroid cancer rates greaterthan 0.5 cases per 1,000 are now selected in the scene.

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2. Click the Selected button. 4. Right-click CASES and click Statistics.

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The table now shows only those features that youselected.

3. Right-click CASES and click Sort Ascending.

The selected province centers are sorted according tothe number of cases.

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The total number of cases in the selected set of11 province centers is 176.

5. Close the Selection Statistics dialog box.


6. Click the Navigate button and click on the scene.

You can work in ArcScene while the attribute table isopen.


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In this exercise you have created 3D features, extrudedpoint features, and interpolated a raster surface from a setof data points. You’ve compared the extruded vector datato the surface data and explored the attributes of the vectordata.


Exercise 4: Building a TIN to represent terrain

The town of Horse Cave, Kentucky, is situated above acave that once served as the source of drinking water andhydroelectric power for the town. Unfortunately, thegroundwater that flows in the cave was polluted byhousehold and industrial waste dumped on the surface andwashed into sinkholes. Dye tracing studies and a three-dimensional survey of the cave revealed the relationshipbetween the cave passages and the town and demonstratedthe connection between open surface dump sites andcontamination of the groundwater in the cave below.

Thanks to the development in 1989 of a new regionalsewage facility and the joint efforts of the Cave ResearchFoundation and the American Cave ConservationAssociation (ACCA), the groundwater is cleaner, and thecave has been restored. It is now operated as a tour caveand educational site by the ACCA.

Cave data was provided courtesy of the ACCA.

Viewing the cave and the landscape

First you will open the BuildTIN scene and view the cavesurvey and some terrain data layers. You’ll use this terraindata to create a TIN and drape some other layers on it tovisualize the relationship of the cave to the town.

1. Click File and click Open.

2. Navigate to the Exercise4 folder and double-clickBuildTIN.sxd.

The scene opens, and you can see the location of roadsand railroads, some sample elevation points, and a fewsignificant contour lines. In the table of contents, youcan see that some layers have been turned off.

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3. Check the box to show the Cavesurvey layer. 1. Click 3D Analyst, point to Create/Modify TIN, and clickCreate TIN From Features.

4. Right-click Cavesurvey and click Zoom To Layer.

The cave survey data consists of PolylineZ features,which are automatically drawn in 3D because they havez-values embedded in their geometry. They appearabove the rest of the data because all of the other layersare drawn with the default elevation of 0.

In the next steps you will build a TIN to provide the baseheights for the streets and a photo of the town.

Creating a TIN from point data

You have a point layer called vipoints point. This coverageconsists of points with an attribute called SPOT thatcontains elevation values taken at these points. You’ll createthe TIN surface model from these points.

2. Check vipoints point.

The SPOT field name appears in the Height sourcedropdown list, and the layer will be triangulated as masspoints.

3. Change the default path so that the new TIN will becreated in the Exercise 4\Terraindata\ folder.

4. Click OK.

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The TIN is created and added to the scene. Note that itis drawn above the Cavesurvey layer; the elevationvalues in the TIN define its base height.

1. Click 3D Analyst, point to Create/Modify TIN, and clickAdd Feature to TIN.

While this TIN is a fairly good model of the surface, youcan make it more accurate by adding some more features.

Adding features to a TIN

Now you will add hard and soft breaklines and a clippolygon to the TIN. You’ll add the railroad features as softbreaklines, so they’ll be represented on the surface butwon’t influence the shape of the surface. You’ll add thebrklines features as hard breaklines with elevation values torefine the shape of the surface in areas that you’re mostinterested in. Finally, you will add the smclp polygon as asoft clip polygon to more smoothly define the edge of theTIN.

2. Check railroad.

3. Click the Height source dropdown arrow and click<none>.

4. Click the Triangulate as dropdown arrow and click softline.

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5. Check brklines. 7. Click the Height source dropdown arrow and click<none>.

8. Click the Tag value field dropdown arrow and click<none>.

You have defined the feature layers that you want to addto your TIN and specified how they should be integratedinto the triangulation.

The Add Features To TIN tool detects that there is anELEVATION field and uses it for the height source. Youwill accept the default and triangulate them as hardbreaklines.

6. Check smclp.

9. Click OK.

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The new features are added to the TIN.

You can see that the railroad follows a bed that has beenleveled somewhat relative to the surface.

Setting features’ base heights from the TIN

Now you will set the base heights for the road and railroadfeatures from the new TIN.

1. Right-click roads and click Properties.



4. Click the dropdown arrow and click tin1.

5. Click OK.

The road features are now draped over the TIN surfacethat you created. Now you will drape the railroadfeatures over the surface.

6. Right-click railroad and click Properties.

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7. Click Obtain heights for layer from surface. The railroad features are now draped over the TINsurface that you created. Next you’ll drape the aerialphoto over the TIN.

Setting raster base heights from the TIN

Including the aerial photo of the town in the scene makesthe relationship between the cave and the town much moreevident. You’ll drape the raster over the TIN and make itpartly transparent so that you’ll be able to see the cavebeneath the surface.

1. Right-click photo.tif and click Properties.

8. Click OK.

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2. Click the Base Heights tab. 6. Type “30” in the Transparent text box.

7. Click OK.

8. Check photo.tif.

Now the aerial photo is 30 percent transparent. You can seelarge patches of the TIN over the photo because the TINand the photo have the same drawing priority. If youwanted the TIN to be visible below the photo, you couldchange its drawing priority to 10 (lowest) on the Renderingtab of the TIN’s Layer Properties dialog box. You couldalso offset the base height of the TIN or the photo by asmall amount.

Cleaning up the scene

To clean up the scene you’ll turn off some layers that areno longer needed and make the cave line symbol larger.

1. Uncheck vipoints point.

2. Uncheck brklines.

3. Uncheck tin1.

4. Double-click the line symbol for the Cavesurvey layer.


4. Click the dropdown arrow and click tin1.

5. Click the Display tab.

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5. Type “5” in the Width box. 1. Click the Launch ArcMap button.

6. Click OK.

Now you can see the three-dimensional passages of thecave, symbolized by thick lines. The surface featuresand the aerial photo provide context, so you can easilysee the relationship of the cave to the town.

Creating a profile of the terrain

The cave follows the valley floor orientation. To get anunderstanding of the shape of the valley, you will create aprofile across the TIN. In order to create a profile, youmust first have a 3D line (feature or graphic). You will startArcMap, copy the TIN to the map, and digitize a line tomake your profile.

ArcMap starts.

2. Click OK.

Now you will add the 3D Analyst toolbar to ArcMap. TheArcMap 3D Analyst toolbar contains a few tools that do notappear on the ArcScene 3D Analyst toolbar. Two of theseare the Interpolate Line tool and the Create Profile Graphtool, which you will use to create your profile of thesurface.

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3. Right-click on one of the ArcMap toolbars and click3D Analyst.

5. Check 3D Analyst.

6. Click Close.

The 3D Analyst toolbar appears.

4. Click Tools and click Extensions.

The 3D Analyst extension is enabled.

7. In the ArcScene table of contents, right-click tin1 andclick Copy.

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8. In the ArcMap table of contents, right-click Layers andclick Paste Layer(s).

11. Click on the upper-left corner of the TIN, drag the lineto the lower-right corner, and double-click to stopdigitizing.

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9. In the ArcMap table of contents, check tin1.

You can create a profile along a line with more than onesegment, but in this case you’ll just make one straightline.

12. Click the Create Profile Graph button.

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10. Click the Interpolate Line button.

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The profile graph is created. You can see the graph on the layout of the map.

15. Click the Data View button to return to data view.

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You can edit the title, subtitle, and other properties of thegraph; you can save, print, or export the graph; you cancopy it to the clipboard; and you can show the graph onthe layout. You can also simply close the graph.

13. Right-click on the Profile Graph Title bar and clickShow on Layout.

14. Close the profile graph window.

Creating a line of sight on the terrain

Another way of understanding the terrain is to create a lineof sight. Lines of sight show what parts of a surface arevisible and what parts are hidden along a line from anobserver point to a target point.

1. Click the Create Line of Sight button.

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2. Type “2” in the Observer offset text box. The line of sight is calculated. The green segments showareas that are visible from the observer point; the redsegments are hidden from the observer.

The line of sight will be calculated to show what isvisible from the perspective of an observer two meterstall, as the z units for this scene are meters.

3. Click on the south slope of the higher land in the upper-right part of the TIN (the observer point), drag the lineto the lower-right part, and release the mouse button(the target point).

4. Close the LineOfSight dialog box.

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Lines of sight, like other graphic lines, can be copiedfrom ArcMap to ArcScene. Now you will copy both thelines you’ve created into the scene.

5. Click Edit and click Select All Elements.

7. In ArcScene, click Edit and click Paste.

Both of the lines you created are selected.

6. Click Edit and click Copy.

The lines are pasted into the scene.

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8. In ArcScene, click the Save button.

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9. In ArcMap, click File and click Exit.

10. Click No.

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Exercise 5: Working with animations in ArcScene

Imagine that you wish to create an animated sequenceshowing the flight of an object over a landscape. You’vecreated a TIN and have draped images over it to show thearea. You also have some data pertaining to a strangephenomenon that has been occurring in the region. You areinterested in displaying all the data in a dynamic way,making an animation to tour points of interest, and showinghow you made the surface. You would also like to modelthe phenomenon by moving a layer in the scene.

The tutorial data has already been assembled in the scenedocument named Animation.sxd. You will use ArcSceneanimation tools to effectively convey the points you want toshow.

Data was supplied courtesy of MassGIS, Commonwealth ofMassachusetts Executive Office of Environmental Affairs.

In this exercise, you will play an existing animation in thescene document, Final Animation_A.sxd, and perform thetasks typically used to create the animation.

Opening the Final Animation_A scene document

In this section, you will play an animation that demonstratessome of the effects that you can create when you animatea scene.

1. In ArcScene, click File and click Open.

2. Navigate to the Exercise5 folder and double-click FinalAnimation_A.sxd.

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This scene contains geographic information and recordedspecial effects that have been combined to make ananimation.

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This animation shows the flight of a hypotheticalunidentified flying object (UFO) over the terrain.

3. Click the Play button.

Playing the scene’s animation

In order to view a scene’s animation, you need to turn onthe Animation toolbar.

1. Click View, point to Toolbars, and click Animation.

The Animation toolbar appears. Now you’ll play theanimation.

2. Click the Open Animation Controls button.

The animation plays, illustrating some of the effects youcan use in an animated scene.

In the next section you will work through the steps usedto make animations like this one.

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Opening the Animation scene document

1. In ArcScene, click File and click Open.

The scene contains an ortho photo, a scannedtopographic map, and other data you need to make youranimation.

2. Navigate to the Exercise 5 folder and double-clickAnimation.sxd.

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For a camera keyframe, the object is the virtual camerathrough which you view the scene. Navigating the scenechanges camera properties that determine its position.

ArcScene interpolates a camera path betweenkeyframes, so you’ll need to capture more views tomake a track that shows animation.

2. Right-click on UFO.lyr and click Zoom To Layer.

In this section, you’ll use the animation tools to capturekeyframes, import tracks, play back your animations, andsave them to a scene document.

There are three types of keyframes that you can use tobuild animations. The first is a camera keyframe. A camerakeyframe is a snapshot of the view you see in a scene. Thesecond, a layer keyframe, is a snapshot of a layer’sproperties. The third type is a scene keyframe, which storesproperties of a scene. In this section, you will create asimple animation from a set of camera keyframes.

Capturing Perspective views as keyframes tomake an animation

The simplest way to make animations is by capturing viewsto be stored as keyframes. The captured views aresnapshots of camera perspectives in a scene at a particulartime. The most fundamental element of an animation is akeyframe. Keyframes are used as snapshots to interpolatebetween in a track. You’ll create a set of keyframes tomake a camera track that will show an animation betweenpoints of interest in your study area.

1. Click the Capture View button to create a camerakeyframe showing the full extent of the scene.

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3. Click the Capture View button to create a camerakeyframe showing the UFO layer.

4. Click the Full Extent button to view all the data.

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8. Zoom to Littleville Lake.5. Click Zoom In on the Navigation toolbar and zoom toGoss Heights, located near the center of your view.

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6. Click the Capture View button to create a camerakeyframe of Goss Heights.


9. Click the Capture View button to capture a view ofLittleville Lake.



The captured views you just made are stored as a set ofcamera keyframes in a camera track. When the track isplayed, it shows a smooth animation between thekeyframes. Next, you’ll play your animation track.

Playing back your animation

You will play back animations using simple tools thatresemble the controls of a video cassette recorder (VCR).

1. Click the Open Animation Controls button.

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3. Click the Play button.

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2. Click the Animation toolbar and drag it to the lower-leftcorner of the scene so it won’t block your view of thetools or data.

An animation is played back by interpolating the cameraposition between the keyframes in the track. In thiscase, the animation shows a virtual tour through theviews you captured.

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Clearing an animation

If you want to start over, you can erase all the tracks youcreated. In this section, you’ll remove the tracks you justcreated so you can improve your animation.

1. Click Animation and click Clear Animation.

All animation tracks are removed from the scene.

Recording navigation

Another way to create a camera track for an animation isto record in real time while you navigate in a scene. In thissection, you will record your view of the scene while younavigate using the Fly tool.

1. Click the Fly tool on the navigation toolbar.

The Fly tool allows you to fly through your scenes.

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2. Click the Record button to start recording yournavigation.

ArcScene begins recording as soon as you click theRecord button. If you don’t navigate right away, yourtrack will reflect this.

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Exercise 6: ArcGlobe basics

Learning how to navigate in ArcGlobe helps you understandhow you can explore your data and teaches you how toaccomplish fundamental tasks that you will use as yourArcGlobe experience grows.

In this exercise you’ll learn how to use the ArcGlobenavigation tools and how to set properties that enhance yourviewing experience. This exercise assumes that you areusing ESRI-supplied default layers.

Examining the default layers in ArcGlobe

First, you’ll open ArcGlobe and learn what kind of data isincluded with ArcGlobe by default.

1. Click the Start menu, point to Programs, then ArcGIS,and click ArcGlobe.

ArcGlobe opens and its default layers are loaded. Noticethe layers that are loaded in the globe by looking at thelist in the table of contents.

2. In the table of contents, click the Type tab.

ArcGlobe categorizes layers according to their type.Layers are classified as elevation, draped, or floating.Elevation layers are raster sources with heightinformation. They give the globe surface terrain. Drapedlayers are features or rasters that use the elevationlayers as a source of their base heights. These layersappear draped over the globe surface. Floating layersare features or rasters that float independently of theterrain surface. They appear offset from other layers,either draped on discrete surfaces or set to someconstant elevation. Note the way the default layers arecategorized. Notice the default layers listed in the Typepage of the ArcGlobe TOC. Both layers are drapedlayers and, therefore, appear draped on the globesurface.

Adding more layers

Default layers serve as a background to any data that youwant to add to ArcGlobe. Next you’ll add some local datafor the Las Vegas area.

1. Click the Add Data button.

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2. Navigate to the location of the Exercise 6 tutorial datafolder.

3. Click las_vegas_area.img, press Shift, and clicklas_vegas_strip.img.

The layers are multiply selected.

4. Click Add.

The image layers are added to ArcGlobe as drapedlayers. You’ll explore them later in the exercise.

Changing a layer’s drawing priority in the table ofcontents

Draped layers that have overlapping extents need to have adrawing priority set so one layer gets drawn on top of theother. ArcGlobe makes some guesses to accomplish this,using criteria such as the cell size of a raster layer.Occasionally, you’ll need to override the ArcGlobe defaultdrawing priorities. One way to do this is to change the orderof draped layers as they appear in the Type page of thetable of contents.

1. Click the Countries layer and drag it so it is just abovethe World Image layer.

A black line indicates where the layer will be placed.

2. Release the mouse pointer to drop the layer in its newposition.

The drawing priority is now set so las_vegas_area.imgand las_vegas_strip.img get drawn on top of theCountries layer.

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Navigate

Zoom In/Out

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1. Click the globe, slowly drag up and to the right, thenrelease the mouse.

The globe rotates and the view angle lowers, so you gain adifferent vantage point.

2. Right-click and drag down.

The pointer changes to the Zoom In/Out pointer, and theview zooms in on the globe. To zoom out, right-click theglobe and drag up.

Navigating in Globe mode

ArcGlobe has two viewing modes: Globe mode and Surfacemode. Globe mode allows you to navigate your data in therealm of the whole globe and sets the camera target to thecenter of the globe. Surface mode lets you work with yourdata at a lower elevation, allows additional perspectiveviewing characteristics, and sets the camera target on thesurface of the globe. In this section, you’ll learn how tonavigate in Globe mode.

The Navigate tool is active when you start ArcGlobe. Youcan see the names of other tools on the Tools toolbar byhovering the pointer over the tool.


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3. Click Full Extent.

The globe displays at full extent.

Turning on the Spin toolbar

You can use the Spin toolbar to automatically spin the globeclockwise or counterclockwise at any speed you wish.

1. Right-click in the menu area and click Spin.

The Spin toolbar appears as an undocked toolbar.

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Using the Spin tools

1. Click the Spin Clockwise button.

The globe continuously spins clockwise around the z-axis. You can change the speed at which it spins.

2. Click the Up arrow on the Speed text box to increase therate at which the globe spins.

Continued clicks will incrementally increase the spinrate. You can also type in a value. Click the Down arrowto decrease the rate.

3. Click the Stop button to stop the globe from spinning.

You can also press Esc to stop the globe from spinning.

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Finding places on the globe

If you have an Internet connection, you can find worldlocations by using the ArcWeb Place Finder in the Finddialog box.

1. Click the Find button.

2. Click ArcWeb Place Finder.

3. In the Find place text box, type “Las Vegas”.

4. Click Find.

5. Right-click on Las Vegas, Nevada, United States andclick Zoom and create bookmark.

The display zooms to Las Vegas, Nevada.

6. In the 3D Bookmark text box, type “Las Vegas Area”.

7. Click OK.

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8. Click Cancel to close the Find dialog box.

The Find tool is an easy way of locating almost any place inthe world. Use it to locate points of interest, then usebookmarks to save perspectives of these places.

Now that you’re zoomed close to the globe surface, you’lllearn how to navigate in Surface mode.

Navigating in Surface mode

When you zoom in close to your data, you can switch toSurface mode to make your navigation apply more correctlyto your new environment. Switching to Surface modeplaces the camera target on the globe surface and givesyou a sense of gravity while you navigate your data.

1. In the table of contents, right-click las_vegas_strip.imgand click Zoom To Layer.

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The display zooms to the Strip area of Las Vegas.

2. Click the Center on Target button.

3. Click the center of the Fountains of Bellagio.

The point you clicked is moved to the center of thedisplay. Centering on a target sets a target on the globesurface and switches to Surface mode.

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4. Click Zoom to Target and click the central dome of theBellagio.

A new target is centered and the display is zoomed to it.

5. Click the Navigate button.

6. Click the bottom of the display and slowly drag up.

The globe rotates, and the viewing angle lowers. Thehorizon becomes visible with a light blue background,and you view the globe in a new perspective.

7. Click the Full Extent button to return the globe to its fullextent position.

Setting some preferences

You can modify the way ArcGlobe functions at both theglobe level and the application level. First, you’ll exploresome application-level options.

1. Click Tools and click Options.

The Options dialog box is where you set application-levelpreferences. The settings will be preserved in allinstances of ArcGlobe.

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2. Click General.

3. Check Animate viewer when using tools and commands.

This option will show smooth transitions from one viewto the next when you use tools that change yourperspective. This will be the standard behavior everytime you open ArcGlobe until you turn off the option.

4. Click OK.

5. Click View, click Bookmarks, and click Las Vegas Area.

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The display moves to the Las Vegas bookmark in asmooth, animated transition. Next, you’ll examine adocument-level option.


Setting a document-level option

1. Double-click Globe layers.

2. Click the Background tab.

3. Click the Sky color dropdown arrow and click a color ofthe morning or evening sky.

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Sky color is the color of the background when you zoomin close to your globe as defined by the lower limit of thetransition zone.

4. Click OK.

If you switch to Surface mode and lower the viewingangle, you’ll notice the background color changing to thecolor you indicated. Use different background colors toconvey different moods.

In this exercise you’ve learned how to differentiatebetween ArcGlobe layer types, navigate in Surface andGlobe modes, find places, and set some application andglobe properties. Now that you’ve learned somefundamentals, you can begin to explore other areas ofArcGlobe. In the next exercise, you’ll learn how to use dataas different layer categories.

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Exercise 7: ArcGlobe layerclassificationArcGlobe classifies layers into three types to help youbetter manage them: elevation layers, draped layers, andfloating layers. In this exercise, you’ll learn how to use theclassifications to help layers provide the right information toyour documents. This exercise assumes that you are usingESRI-supplied default layers.

Adding elevation layers

Elevation layers provide height information to the globesurface. You’ll use rasters with height source information toprovide topography to the globe surface, making it a globeterrain.

1. Click the Start menu, point to Programs, then ArcGIS,and click ArcGlobe.

ArcGlobe opens, and its default layers are loaded.

2. In the TOC, click Type to show the page of the TOCthat indicates layer classifications.

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3. Right-click Globe layers, point to Add Data, and clickAdd elevation data.

Indicating that you want to add a specific type of dataadds layers into that category.

4. Navigate to the location of the Exercise7 folder.

5. Select sw_usa_grid.

6. Click Add.

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The raster is added to the Elevation category and will beused as a source of elevation for the globe surface.

Adding draped layers

Layers classified as draped are placed on the globe surfaceand use any elevation data present to show base heights.Next, you’ll add some images that will be draped on theglobe terrain you created.

1. Right-click Globe layers, point to Add Data, and clickAdd draped data.

Layers you now choose to add will be draped on theglobe terrain.

2. Click angelus oaks.tif, press Ctrl, and clicksocal_mmosaic.jpg.

The layers are both selected.

3. Click Add.

4. Right-click angelus oaks.tif and click Zoom To Layer.

The display zooms to the extent of the layer. A fewmoments will pass before the layer is shown at fullresolution as the on-demand cache is built. Once thecache is built, you’ll be able to revisit the area anddisplay the layer quickly.

The Angelus Oaks imagery appears washed out due tothe Countries layer being drawn with a higher drawingpriority. Next, you’ll learn how to change a drapedlayer’s drawing priority.

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Changing a layer’s drawing priority in the table ofcontents

Draped layers that have overlapping extents need to have adrawing priority set so one layer gets drawn on top of theother. ArcGlobe makes some guesses to accomplish this,using criteria such as the cell size of a raster layer.Occasionally, you’ll need to override the ArcGlobe defaultdrawing priorities. One way to do this is to change the orderof draped layers as they appear in the Type page of thetable of contents.

1. Click the Countries layer and drag it so it is just abovethe World Image layer.

A black line indicates where the layer will be placed.

2. Release the mouse pointer to drop the layer in its newposition.

The drawing priority is now set so angelus oaks.tif andsocal_mmosaic.sid get drawn on top of the Countrieslayer.

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Setting a target to initiate Surface mode

1. Press Ctrl and click in the middle of the display.

You’ve initiated Surface mode and set a target at thelocation on the globe surface where you clicked.

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Adding floating layers

Floating layers are layers that float independently of theglobe surface. Next, you’ll add a raster as a floating layerand set it to elevations not connected with the globesurface.

1. Click Globe layers, point to Add Data, and click Addfloating data.

2. Click o3_99x10k.

o3_99x10k is a raster showing average annual ozoneconcentration for 1999 in California.

3. Click Add.

The layer is added to the Floating category.

2. Click the bottom of the display and slowly drag up.

The globe terrain you created becomes discernible asyou investigate the imagery you added.

3. Click the Full Extent button to return the display to theoriginal view.


Setting elevation properties of floating layers

1. Right-click o3_99x10k and click Properties.

2. Click the Elevation tab.

1 3. In the Layer floats independent of the globe surface,draped on dropdown menu, click Elevation valuesprovided by this layer .

4. In the Add a constant elevation offset in meters text box,type “5000”.

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5. Click Symbology.

6. In the Color Ramp dropdown menu, select the red toblue color ramp.

7. Check Invert.

This inverts the color ramp so that high values will bedisplayed as red, low values as blue.

8. Click OK.

You’ve set the raster to use its own values as a sourceof base heights, offset those heights 5,000 meters fromthe globe surface, and symbolized the concentrationvalues with color. Next you’ll take a look at how thisappears in the display and set a vertical exaggeration toaccentuate the elevation.

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Setting a vertical exaggeration factor for floatinglayers

1. Right-click o3_99x10k and click Zoom To Layer.

The layer is displayed in the view.

2. Click the Navigation Mode button to change the mode toSurface navigation.


3. Click the bottom of the display and slowly drag thecursor up.

This will allow you to see the effect of changing thevertical exaggeration.

4. Double-click Globe layers.


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6. In the Vertical Exaggeration Of floating layers dropdownmenu, select or type a value of “10”.

The floating layer will be exaggerated by a factor of 10.

7. Click OK.

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Examine the floating layer you’ve created. You’ll see a3D raster showing average ozone concentrations inCalifornia in 1999. The layer floats above the state ofCalifornia and is a surface that is different from theterrain below.

In this exercise, you learned how to differentiate layer typesin ArcGlobe, saw the effect they have on the globe, and setproperties to improve their display. Explore Exercise7.3ddglobe document in the Exercise7 folder to discoveradditional ways to enhance your globe documents. Thedocument contains layers saved with custom settings,bookmarks, globe lighting, and animation tracks.

IN THIS CHAPTER

77

Creating surface models 3• Representing surfaces with

rasters and TINs

• Creating a raster from points

• Interpolator assumptions

• Raster output controls

• Creating a TIN from vector data

• Modifying a TIN

• Creating a TIN from a raster

• Creating a raster from a TIN

3D Analyst lets you work with real or hypothetical surfaces with two typesof surface models: rasters and TINs. You can use existing models, or youcan create your own from a variety of data sources. The two main methodsof creating surface models are by interpolation and triangulation. You canchoose from several interpolation methods, including Inverse DistanceWeighted, Spline, Kriging, and Natural Neighbors interpolation. You canbuild triangulated surfaces by creating a TIN or by adding elements to anexisting TIN. You can also convert between TIN and raster surface models.


What are surfaces and surface models?

A surface is a continuous field of values that may vary over aninfinite number of points. For example, points in an area on theearth’s surface may vary in elevation, proximity to a feature, orconcentration of a particular chemical. Any of these values maybe represented on the z-axis in a three-dimensional x,y,zcoordinate system, so they are often called z-values.

Because a surface contains an infinite number of points, it isimpossible to measure and record the z-value at every point.Surface models allow you to store surface information in a GIS.A surface model approximates a surface by taking a sample ofthe values at different points on the surface and then interpolatingthe values between these points.

Raster surfaces

Raster surfaces are usually stored in grid format. A grid consistsof a rectangular array of uniformly spaced cells with z-values.The smaller the cells, the greater the locational precision of thegrid.

Surface model of chemical concentration across an area withpoints showing where the concentration was sampled

Higher precision grid Lower precision grid

Grid in perspective view

3D Analyst uses two types of surface models: rasters and TINs.Rasters represent a surface as a regular grid of locations withsampled or interpolated values. TINs represent a surface as a setof irregularly located points linked to form a network of triangleswith z-values stored at the nodes.

You cannot locate individual features—for example, the summitof a mountain—any more precisely than the size of the grid cells.

Rasters are also used to store images and thematic grid data.

CREATING SURFACE MODELS 79

Nodes and edges of a TIN Nodes, edges, and faces

TIN in perspective view

TIN surfaces

TINs consist of nodes that store z-values, connected by edges toform contiguous, nonoverlapping triangular facets. The edges inTINs can be used to capture the position of linear features thatplay an important role in the surface, such as ridgelines or streamcourses.

The input features used to create a TIN remain in the sameposition as nodes or edges in the TIN. This allows a TIN topreserve all of the precision of the input data whilesimultaneously modeling the values between known points. Youcan include precisely located features on a surface—such asmountain peaks, roads, and streams—by using them as inputfeatures to the TIN.

TIN models are less widely available than raster surface modelsand tend to be more expensive to build and process. The cost ofobtaining good source data can be high, and processing TINstends to be less efficient than processing raster data because oftheir complex data structure.

TINs are typically used for high precision modeling of smallerareas, such as in engineering applications, where they are usefulbecause they allow calculations of planimetric area, surface area,and volume.

Because the nodes can be placed irregularly over the surface,TINs can have a higher resolution in areas where a surface ishighly variable or where more detail is desired and a lowerresolution in areas that are less variable or of less interest.


Creating raster surfaces from points

Surfaces of continuous data are usually generated from samplestaken at points across the area. For example, the irregularlyspaced weather stations in a region can be used to create rastersurfaces of temperature or air pressure. The resulting surface is aregular grid of values.

What is interpolation?

Interpolation predicts values for cells in a raster from a limitednumber of sample data points. It can be used to predict unknownvalues for any geographic point data: elevation, rainfall, chemicalconcentrations, noise levels, and so on.

close together tend to have similar characteristics. For instance, ifit is snowing on one side of the street, you can predict with a highlevel of confidence that it is also snowing on the other side of thestreet. You would be less sure if it was snowing across town andless confident still about the state of the weather in the nextcounty.

Why interpolate?

Visiting every location in a study area to measure the height,magnitude, or concentration of a phenomenon is usually difficultor expensive. Instead, dispersed sample input point locations canbe selected, and a predicted value can be assigned to all otherlocations. Input points can be either randomly, strategically, orregularly spaced points containing height, concentration, ormagnitude measurements.

A typical use for point interpolation is to create an elevationsurface from a set of sample measurements. Each point representsa location where the elevation has been measured. The valuesbetween these input points are predicted by interpolation.

High

Low

On the left is a point dataset of known values. On the right is a rasterinterpolated from these points. Unknown values are predicted with amathematical formula that uses the values of nearby known points.

In this example the input points happen to fall on cell centers—this is unlikely in practice. One problem with creating rasters byinterpolation is that the original information is degraded to someextent—even when a data point falls within a cell, it is notguaranteed that the cell will have exactly the same value.

Interpolation is based on the assumption that spatially distributedobjects are spatially correlated; in other words, things that are The resulting grid is a prediction of what the elevation is at any

location on the actual surface.


Interpolation methods

There are several ways to create raster surfaces from point data.You can use the IDW, Natural Neighbors, Spline, and Krigingmethods to create surfaces through the user interface of3D Analyst. Trend surface interpolation is available throughcustomization.

Each interpolation method makes assumptions about how todetermine the estimated values. Depending on the phenomenonyou are modeling and the distribution of sample points, differentinterpolators produce better models of the actual surface.Regardless of the interpolator, the more input points and the moreeven their distribution, the more reliable the results.

Inverse Distance Weighted: This interpolation method assumesthat each sample point has a local influence that diminishes withdistance. It weights the points closer to the processing cell moreheavily than those farther away. Either a specified number ofpoints or all of the points within a given radius can be used todetermine the value of each output cell. This method isappropriate when the variable being mapped decreases ininfluence with distance from the sampled location. For example,when interpolating a surface of consumer purchasing power for aretail site analysis, the purchasing power of a more distantlocation will have less influence because people are more likelyto shop closer to home.

Natural Neighbors: Like IDW, this interpolation method is aweighted-average interpolation method. However, instead offinding an interpolated point’s value using all of the input pointsweighted by their distance, Natural Neighbors interpolationcreates a Delauney Triangulation of the input points and selectsthe closest nodes that form a convex hull around the interpolationpoint, then weights their values by proportionate area. Thismethod is most appropriate where sample data points aredistributed with uneven density. It is a good general-purposeinterpolation technique and has the advantage that you do not

have to specify parameters, such as radius, number of neighbors,or weights.

Spline: This general-purpose interpolation method fits aminimum-curvature surface through the input points.Conceptually, this is like bending a sheet of rubber to passthrough the points while minimizing the total curvature of thesurface. It fits a mathematical function—a minimum curvature,two-dimensional, thin-plate spline—to a specified number of thenearest input points while passing through all input points. Thismethod is best for gradually varying surfaces such as elevations,water-table depths, or pollution concentrations. It is notappropriate when there are large changes within a shorthorizontal distance because it can overshoot estimated values.

Kriging: This interpolation method assumes that the distance ordirection between sample points reflects a spatial correlation thatcan be used to explain variation in the surface. Kriging fits amathematical function to a specified number of points, or allpoints within a specified radius, to determine the output value foreach location. Kriging is a multistep process; it includesexploratory statistical analysis of the data, variogram modeling,creating the surface, and, optionally, exploring a variance surface.This function is most appropriate when you know there is aspatially correlated distance or directional bias in the data. It isoften used in soil science and geology.

Trend: This interpolation method fits a mathematical function—apolynomial of specified order—to all input points. This methoduses a least-squares regression fit, which results in a surface thatminimizes the variance of the surface in relation to the inputvalues. The surface is constructed so that for every input point,the total of the differences between the actual values and theestimated values (the variance) will be the smallest possible. Theresulting surface rarely goes through the input points. The Trendmethod is available through customization but not through the 3DAnalyst user interface.


Details on the interpolation methods

Of the available interpolation methods, IDW, Spline, and Kriging,each has some parameters that influence how the interpolation isdone. The Natural Neighbors method only requires that youspecify the output cell size.

Inverse Distance Weighted

IDW estimates grid cell values by averaging the values of sampledata points in the vicinity of each cell. The closer a point is to thecenter of the cell being estimated, the more influence, or weight,it has in the averaging process. There are several parameters youcan set to control the IDW interpolation. These are the Power, theRadius Type, and Barriers.

Power: With IDW you can control the significance of knownpoints on the interpolated values based on their distance from theoutput point. By defining a high power, more emphasis is placedon the nearest points, and the resulting surface will have moredetail (be less smooth). Specifying a lower power will give moreinfluence to the points that are further away, resulting in asmoother surface. A power of 2 is most commonly used and is thedefault.

The characteristics of the interpolated surface can also becontrolled by limiting the number of input points used forcalculating each interpolated point:

Radius Type: Fixed

With a fixed radius, the distance of the radius is constant, and foreach interpolated point, all of the points within the circle will beused. By specifying a minimum count, you can ensure that if in acertain area the number of points is less than the count specified,the radius of the circle will be increased until the count is met.

Radius Type: Variable

With a variable radius, the number of points used in calculatingthe value of the interpolated point, or count, is specified. Thismakes the radius vary for each interpolated point, depending onhow far it has to search around each interpolated point to reachthe specified number of input points. The variable radiusapproach may produce better surfaces when the density of inputpoints varies significantly from one area to another. If you knowyou have areas with sparsely distributed input points, you canspecify a maximum distance to limit the potential radius of thecircle. In this case, if the number of points is not reached beforethe maximum distance of the radius is reached, fewer points willbe used in the calculation of the interpolated point.

Barrier: A line or polygon dataset can be used as a break thatlimits the search for input sample points. A line can represent acliff, ridge, or some other interruption in a landscape. Only thoseinput sample points on the same side of the barrier as the currentprocessing cell will be considered. A choice of No Barriers willuse all points within the identified radius.

Spline

Spline estimates values using a mathematical function thatminimizes overall surface curvature, resulting in a smooth surfacethat passes exactly through the input points.

There are two Spline methods: Regularized and Tension. Theyare described below, as well as the meaning of the weightparameter, which changes depending on the Spline method. Bothmethods share a number of points parameter.

Number of points: For both methods, this parameter defines thenumber of points used in the calculation of each interpolatedpoint. The more input points you specify, the more each cell isinfluenced by distant points, and the smoother the surface.


Regularized spline

The Regularized method creates a smooth, gradually changingsurface with values that may lie outside the sample data range.

Weight: Defines the weight of the third derivatives of thesurface in the curvature minimization expression. The higher theweight, the smoother the surface.

The values entered for this parameter must be equal to or greaterthan zero. The typical values that may be used are 0, .001, .01,.1, and .5.

Tension spline

The Tension method tunes the stiffness of the surface accordingto the character of the modeled phenomenon. It creates a lesssmooth surface with values more closely constrained by thesample data range.

Weight: Defines the weight of tension. The higher the weight,the coarser the surface.

The values entered have to be equal to or greater than zero. Thetypical values are 0, 1, 5, and 10.

Kriging

IDW and Spline (discussed earlier) are referred to asdeterministic interpolation methods because they are directlybased on the surrounding measured values or on specifiedmathematical formulas that determine the smoothness of theresulting surface. A second family of interpolation methodsconsists of geostatistical methods (such as kriging), which arebased on statistical models that include autocorrelation (thestatistical relationship among the measured points). Because ofthis, not only do these techniques have the capability ofproducing a prediction surface, but they can also provide somemeasure of the certainty or accuracy of the predictions.

Kriging is similar to IDW in that it weights the surroundingmeasured values to derive a prediction for an unmeasuredlocation. The general formula for both interpolators is formed asa weighted sum of the data:

where

Z(si) is the measured value at the ith location;

λι is an unknown weight for the measured value at the ithlocation;

s0 is the prediction location;

N is the number of measured values.

In IDW, the weight, λι, depends solely on the distance to theprediction location. However, in Kriging, the weights are basednot only on the distance between the measured points and theprediction location but also on the overall spatial arrangementamong the measured points. To use the spatial arrangement in theweights, the spatial autocorrelation must be quantified. Thus, inOrdinary Kriging, the weight, λι, depends on a fitted model to themeasured points, the distance to the prediction location, and thespatial relationships among the measured values around theprediction location.

To make a prediction with Kriging, two tasks are necessary: (1) touncover the dependency rules and (2) to make the predictions. Torealize these two tasks, Kriging goes through a two-step process:(1) the creation of variograms and covariance functions toestimate the statistical dependence—called spatialautocorrelation—values, which depends on your model ofautocorrelation—fitting a model—and (2) actually predicting the

∑=

=N

iiiZZ

10 )()(ˆ ss λ


unknown values—making a prediction. It is because of these twodistinct tasks that it has been said that Kriging uses the datatwice: the first time to estimate the spatial autocorrelation of thedata and the second time to make the predictions.

Variography

Fitting a model or spatial modeling is also known as structuralanalysis or variography. In spatial modeling of the structure ofthe measured points, you will begin with a graph of the empiricalsemivariogram, computed as:

Semivariogram(distance h) = 0.5 * average[ (value at location i –value at location j)2]

for all pairs of locations separated by distance h. The formulainvolves calculating the difference squared between the values ofthe paired locations. The image below shows the pairing of onepoint (the red point) with all other measured locations. Thisprocess continues for each measured point.

Often each pair of locations has a unique distance, and there areoften many pairs of points. To plot all pairs quickly becomesunmanageable. Instead of plotting each pair, the pairs aregrouped into lag bins. For example, compute the averagesemivariance for all pairs of points that are greater than 40 metersapart but less than 50 meters. The empirical semivariogram is agraph of the averaged semivariogram values on the y-axis and thedistance, or lag, on the x-axis (see diagram below).

Spatial autocorrelation quantifies a basic principle of geography;things that are closer are more alike than things farther apart.Thus, pairs of locations that are closer—far left on the x-axis ofthe semivariogram cloud—should have more similar values—lowon the y-axis of the semivariogram cloud. As pairs of locationsbecome farther apart—moving to the right on the x-axis of thesemivariogram cloud—they should become more dissimilar andhave a higher squared difference—move up on the y-axis of thesemivariogram cloud.

Distance

Semivariance


Fitting a model to the empirical semivariogram

The next step is to fit a model to the points forming the empiricalsemivariogram. Semivariogram modeling is a key step betweenspatial description and spatial prediction. The main application ofKriging is the prediction of attribute values at unsampledlocations. You have seen how the empirical semivariogramprovides information on the spatial autocorrelation of datasets.However, it does not provide information for all possibledirections and distances. For this reason, and to ensure thatKriging predictions have positive Kriging variances, it isnecessary to fit a model (i.e., a continuous function or curve) tothe empirical semivariogram. Abstractly, this is similar toregression analysis, where a continuous line or curve is fitted.

Select some function that serves as your model, for example, aspherical type that rises at first and then levels off for largerdistances beyond a certain range (see previous image). There aredeviations of the points on the empirical semivariogram from themodel; some points are above the model curve, and some pointsare below. But if you add the distance each point is above the lineand add the distance each point is below the line, the two valuesshould be similar. There are a lot of different semivariogrammodels to choose from.

Different types of semivariogram models

3D Analyst provides the following functions to choose from tomodel the empirical semivariogram: Circular, Spherical,Exponential, Gaussian, and Linear. The selected model influencesthe prediction of the unknown values, particularly when the shapeof the curve near the origin differs significantly. The steeper thecurve is near the origin, the more influence the closest neighborswill have on the prediction. As a result, the output surface will beless smooth. Each model is designed to fit different types ofphenomenon more accurately.

The diagrams below show two common models and identify howthe functions differ:

• The Spherical Model

This model shows a progressive decrease of spatialautocorrelation—equivalently, an increase of semivariance—untilsome distance, beyond which autocorrelation is zero. Thespherical model is one of the most commonly used models.

• The Exponential Model

Distance

Semivariance

Distance

Semivariance


This model is applied when spatial autocorrelation decreasesexponentially with increasing distance. Here the autocorrelationdisappears completely only at an infinite distance. Theexponential model is also a commonly used model.

The choice of which model to use in 3D Analyst is based on thespatial autocorrelation of the data and on prior knowledge of thephenomenon.

Understanding a semivariogram—the range, sill, andnugget

As previously discussed, the semivariogram depicts the spatialautocorrelation of the measured sample points. Because of abasic principle of geography—things that are closer are morealike—measured points that are close will generally have a smallerdifference squared than those farther apart. Once each pair oflocations is plotted—after being binned—a model is fit throughthem. There are certain characteristics that are commonly used todescribe these models.

The range and sill

When you look at the model of a semivariogram, you will noticethat at a certain distance the model levels out. The distance wherethe model first flattens out is known as the range.

Sample locations separated by distances closer than the range arespatially autocorrelated, whereas locations farther apart than therange are not.

The value at which the semivariogram model attains the range—the value on the y-axis—is called the sill. The partial sill is the sillminus the nugget (see the following section).

The nugget

Theoretically, at zero separation distance (i.e., lag = 0), thesemivariogram value is zero. However, at an infinitely smallseparation distance, the semivariogram often exhibits a nuggeteffect, which is some value greater than zero. If the semivariogrammodel intercepts the y-axis at 2, then the nugget is 2.

The nugget effect can be attributed to measurement errors orspatial sources of variation at distances smaller than the samplinginterval, or both. Measurement error occurs because of the errorinherent in measuring devices. Natural phenomena can varyspatially over a range of scales (i.e., micro or macro scales).Variation at micro scales smaller than the sampling distances willappear as part of the nugget effect. Before collecting data, it isimportant to gain some understanding of the scales of spatialvariation that you are interested in.

Making a prediction

The first task of uncovering the dependence (autocorrelation) inyour data has been accomplished. You have also finished with thefirst use of the data, where the spatial information in the data—tocompute distances—is used to model the spatial autocorrelation.Once you have the spatial autocorrelation, you proceed withprediction using the fitted model; thereafter, the empiricalsemivariogram is set aside.

Distance

γ(si,sj)

Nugget

Partial Sill

Sill

Range

0


For the second task, you use the data again to make predictions.Like IDW interpolation, Kriging forms weights from surroundingmeasured values to predict at unmeasured locations. As withIDW interpolation, the measured values closest to theunmeasured locations have the most influence. However, theKriging weights for the surrounding measured points are moresophisticated than those of IDW. IDW uses a simple algorithmbased on distance, but kriging weights come from asemivariogram that was developed by looking at the spatialnature of the data. To create a continuous surface or map of thephenomenon, predictions are made for each location (cellcenters) in the study area based on the semivariogram and thespatial arrangement of measured values that are nearby.

Search radius

You can assume that as the locations get farther from theprediction location, the measured values will have less spatialautocorrelation with the unknown value for the location you arepredicting. Thus, you can eliminate those farther locations withlittle influence. Not only is there less relationship with fartherlocations, but it is also possible that the farther locations mayhave a negative influence if they are located in an area muchdifferent than the prediction location. Another reason to usesearch neighborhoods is for computational speed. The smaller thesearch neighborhood, the faster the predictions can be made. As aresult, it is common practice to limit the number of points that areused when making a prediction by specifying a searchneighborhood. The specified shape of the neighborhood restrictshow far and where to look for the measured values to be used inthe prediction. Other neighborhood parameters restrict thelocations that will be used within that shape so, for example, youcan define the maximum and minimum number of measuredpoints to use within the neighborhood.

Using the configuration of the valid points within the specifiedneighborhood around the prediction location in conjunction withthe model fit to the semivariogram, the weights for the measuredlocations can be determined. From the weights and the values, aprediction can be made for the unknown value at the predictionlocation.

3D Analyst has two neighborhood types, fixed and variable.

Fixed search radius

A fixed search radius requires a distance and a minimum numberof points. The distance dictates the radius of the circle of theneighborhood (in map units). The distance of the radius isconstant, so for each interpolated cell, the radius of the circleused to find input points is the same. The minimum number ofpoints indicates the minimum number of measured points to usewithin the neighborhood. All the measured points that fall withinthe radius will be used in the calculation of each interpolated cell.When there are fewer measured points in the neighborhood thanthe specified minimum, the search radius will increase until it canencompass the minimum number of points. The specified fixedsearch radius will be used for each interpolated cell (cell center)in the study area, thus if your measured points are not spread outequally, which they rarely are, there likely will be a differentnumber of measured points used in the different neighborhoodsfor the various predictions.

Variable search radius

With a variable search radius, the number of points used incalculating the value of the interpolated cell is specified, whichmakes the radius distance vary for each interpolated cell,depending on how far it has to search around each interpolatedcell to reach the specified number of input points. Thus, someneighborhoods can be small and others can be large depending onthe density of the measured points near the interpolated cell. Youcan also specify a maximum distance—in map units—that the


search radius cannot exceed. If the radius for a particularneighborhood reaches the maximum radius before obtaining thespecified number of points, the prediction for that location willbe performed on the number of measured points within themaximum radius.

Kriging methods

3D Analyst provides two kriging methods: Ordinary andUniversal Kriging.

Ordinary Kriging

Ordinary Kriging is the most general and widely used of thekriging methods. It assumes the constant mean is unknown. Thisis a reasonable assumption unless there is some scientific reasonto reject this assumption.

Universal Kriging

Universal Kriging assumes that there is an overriding trend in thedata (i.e., a prevailing wind) and it can be modeled by adeterministic function, a polynomial. This polynomial issubtracted from the original measured points, and theautocorrelation is modeled from the random errors. Once themodel is fit to the random errors, before making a prediction, thepolynomial is added back to the predictions to give youmeaningful results. Universal Kriging should only be used whenyou know there is a trend in your data and you can give ascientific justification to describe it.


Interpolating araster surfaceYou can create a new rastersurface from input point datausing four different interpolationmethods. Each method hasparameters that you can modifyto create a raster that suits yourneeds.

Interpolating usingInverse DistanceWeighted with a variablesearch radius

1. Click 3D Analyst, point toInterpolate to Raster, andclick Inverse DistanceWeighted.

2. Click the dropdown arrow andchoose the input point datasource.

3. Click the field that containsthe attribute data that youwant to interpolate.

4. Type the power.

5. Click the dropdown arrow andclick Variable.

6. Type the number of points touse as input from within themaximum distance.

7. Type the maximum distanceto search for points to use inthe interpolation.

8. Optionally, check the box andselect or navigate to a featureclass to use as barriers tointerpolation.

9. Type a cell size for the outputraster.

10. Optionally, type a name forthe Output raster. If you donot, the raster will betemporary.

11. Click OK.

Tip

What is the power?The power is the exponent of thedistance used in IDW interpola-tion. Higher numbers result in alower influence of distant points oneach processing cell. Lowernumbers result in more smoothingof the surface. Reasonable powervalues range between 0.5 and 3.

Tip

What is a variable radius?A variable radius interpolationuses the closest n points that itfinds within the maximum distanceof the output cell as input. Incontrast, a fixed radius uses all ofthe points within the specifieddistance.

Tip

What are barriers?A feature class of linear features,such as faults or cliffs, can be usedto limit the search for input pointsfor the interpolation of each outputcell.

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Interpolating usingInverse DistanceWeighted with a fixedsearch radius

1. Click 3D Analyst, point toInterpolate to Raster, andclick Inverse DistanceWeighted.


3. Click the dropdown arrow andchoose the field that containsthe attribute data that youwant to interpolate.

4. Type the power.

5. Click the dropdown arrow andclick Fixed.

6. Type the distance withinwhich to search for inputpoints.

7. Type the minimum number ofpoints that must be includedin the interpolation for a cell.

8. Optionally, check the box andselect or navigate to a featureclass to use as barriers tointerpolation.



11. Click OK.

Tip

What is the MinimumCount?A fixed radius interpolation usesall of the points within thespecified distance. If no points arefound within the search radius, thesearch radius will increase for thecell until the specified minimumnumber of points is found.

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Interpolating using aTension spline

1. Click 3D Analyst, point toInterpolate to Raster, andclick Spline.



4. Click the dropdown arrow andclick Tension.

5. Type a weight.




9. Click OK.

Tip

What is a Tension spline?A spline interpolation is a methodof fitting a surface to a set ofpoints. Think of the surface as athin plate of slightly elasticmaterial deformed to fit the points.In a Tension spline, you cancontrol the elasticity of the surface.

Tip

What is the weight value?The weight value in a Tensionspline adjusts the elasticity of thesurface. A weight of 0 results in abasic thin-plate spline interpola-tion. Larger values increase theelasticity of the surface. Typicalweight values are 0, 1, 5, and 10.

Tip

What is the number ofpoints?The number of points controls theaverage number of points to becontained in each region used incomputing the surface. The regionsare rectangles of equal size, andthe number of regions is deter-mined by dividing the total numberof input points by the number ofpoints. When the data is notuniformly distributed, the actualnumber of points in a region maybe different from the number ofpoints. If the number of points in aregion is less than eight, the regionis expanded until it contains eightpoints.

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Interpolating using aRegularized spline

1. Click 3D Analyst, point toInterpolate to Raster, andclick Spline.



4. Click the dropdown arrow andclick Regularized.

5. Type a weight.




9. Click OK.

Tip

What is a Regularizedspline?A Regularized spline lets youcontrol the smoothness of thesurface. Regularized splines areuseful if you will need to calculatethe second derivative of theinterpolated surface.

Tip

What is the weight?The weight value in a Regularizedspline adjusts the smoothness ofthe surface. The weight specifiesthe weight (tau) attached to thethird derivative term, used inminimizing the curvature of thesurface. Larger values result insmoother surfaces and smoothfirst-derivative (slope) surfaces.Values between 0 and 0.5 aresuitable.

Tip

What is the number ofpoints?The number of points controls theaverage number of points con-tained in each region used incomputing the surface. The regionsare rectangles of equal size; thenumber of regions is determined bydividing the total number of inputpoints by the number of points.When the data is not uniformlydistributed, the actual number ofpoints in a region may be differentfrom the number of points. If thenumber of points in a region is lessthan eight, the region is expandeduntil it contains eight points.

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Creating a surface usingKriging interpolation witha variable radius

1. Click the 3D Analystdropdown arrow, point toInterpolate to Raster, andclick Kriging.

2. Click the dropdown arrow andclick the Input points dataset.

3. Click the Z value fielddropdown arrow and click thefield you wish to use.

4. Click the Kriging method youwish to use.

5. Click the Semivariogrammodel dropdown arrow andclick the model you wish touse.

6. Click the Search radius typedropdown arrow and clickVariable.

7. Optionally, change the defaultNumber of points.

8. Optionally, specify a Maxi-mum distance.

9. Optionally, change the defaultOutput cell size.

10. Optionally, check the CreatePrediction of standard errorcheck box.

11. Specify a name for theoutputs or leave the defaultto create a temporary datasetin your working directory.

12. Click OK.

KriginginterpolationThere are two kriging methods:Ordinary and Universal.

Ordinary Kriging is the mostgeneral and widely used of thekriging methods and is thedefault. It assumes the constantmean is unknown. UniversalKriging should only be usedwhen you know there is a trendin your data and you can give ascientific justification to describeit.

By using a variable search radius,you can specify the number ofpoints to use in calculating thevalue of the interpolated cell.This makes the search radiusvariable for each interpolatedcell, depending on how far it hasto stretch to reach the specifiednumber of input points.

Specifying a maximum distancelimits the potential size of theradius of the circle. If the numberof points is not reached beforethe maximum distance of theradius is reached, fewer pointswill be used in the calculation ofthe interpolated cell. u

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Creating a surface usingKriging interpolation witha fixed radius

1. Click the 3D Analystdropdown arrow, point toInterpolate to Raster, andclick Kriging.

2. Click the dropdown arrow andclick the Input points dataset.

3. Click the Z value fielddropdown arrow and click thefield you wish to use.

4. Click the Kriging method youwish to use.

5. Click the Semivariogrammodel dropdown arrow andclick the model you wish touse.

6. Click the Search radius typedropdown arrow and clickFixed.

7. Optionally, change the defaultDistance for the search radiussetting.

8. Optionally, change theMinimum number of points.

9. Optionally, change the defaultOutput cell size.

10. Optionally, check the CreatePrediction of standard errorcheck box.

11. Specify a name for theoutputs or leave the defaultto create a temporary datasetin your working directory.

12. Click OK.

With a Fixed radius, the radius ofthe circle used to find inputpoints is the same for eachinterpolated cell. The defaultradius is five times the cell sizeof the output grid. By specifyinga minimum number of points,you can ensure that within thefixed radius, at least a minimumnumber of input points will beused in the calculation of eachinterpolated cell.

Tip

Deciding on the radius orthe number of pointsUse the measure tool on the Toolstoolbar to measure distancebetween points to get an idea ofthe radius and number of points touse.

Tip

Changing the lag size,major range, partial sill,and nuggetClick Advanced Parameters on theKriging dialog box to modify theseparameters.

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Interpolating usingNatural Neighbors

1. Click 3D Analyst, point toInterpolate to Raster, andclick Natural Neighbors.

2. Click the dropdown arrow andchoose the Input points datasource.

3. Click the dropdown arrow andclick the height source.


5. Type a name for the Outputraster.

6. Click OK.

Tip

What is a NaturalNeighbors interpolation?A Natural Neighbors interpolationcombines some TIN functionalitywith the raster interpolationprocess. The raster surface isinterpolated using the input datapoints that are natural neighborsof the cell.

The interpolation method firstcreates a Delauney Triangulationof the input points (part of the TINcreation process); the points arenodes in a triangulation thatfollows the rule that a circlearound each triangle can containno other nodes. This means that,collectively, the triangles areconstrained to be as close toequilateral triangles as possible.

For each data point, the naturalneighbors are the minimumnumber of nodes in the triangula-tion that connect to form a convexhull around the point.

The weight of each neighbor pointis determined through the use of aThiessen/Voroni technique thatevaluates its area of influence.

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1. Click 3D Analyst and clickOptions.


3. Type the name of the newworking directory.

Alternatively, you can browseto your new working directory.

4. Click OK.

Saving all rastersin a specifiedlocationYou can specify a folder where3D Analyst will save outputtemporary rasters. Temporaryrasters are automatically deletedwhen you exit the applicationwhere they were created, unlessyou save a layer file, scene, ormap document that refers to theraster.

There are two ways to specifywhere your analysis resultsshould go. The first way is tospecify a location on disk foryour results using the AnalysisOptions dialog box before youperform any analysis. This wayall your analysis results will go tothis directory. The second way isto specify a location on disk eachtime you perform analysis in eachof the function dialog boxes.This is useful if you want to sortyour analysis results intodifferent folders.

By default, temporary rasters aresaved to your system’s temporarydirectory, usually C:\temp.

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3. Browse to the raster that willbe the analysis mask.

4. Click OK.

Setting ananalysis maskAn analysis mask is a raster thatallows an analysis operation tobe performed only on certaincells of interest in another raster.It contains selected cells that areof interest for future processingand other cells that are to bemasked out. The masked-outcells should have a value ofnodata.

Setting an analysis mask meansthat processing will only occuron selected cells and that allother cells will be assignedvalues of NoData.

Setting an analysis mask is a two-step process:

1. The analysis mask must first becreated using the Reclassifydialog box. See the section onreclassifying rasters for moreinformation about creating ananalysis mask.

2. The analysis mask must thenbe specified in the General tabof the Analysis Options dialogbox in order for it to be used inall subsequent analysis.

Analysis masks will work on theoutput of the surface analysistools in 3D Analyst.

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Setting thecoordinatesystem for youranalysis resultsRasters with different coordinatesystems can be projected on thefly into a single data frame with agiven coordinate system fordisplay and analysis in ArcMap.When you have rasters in morethan one coordinate system inyour scene or map, you need tospecify the coordinate system forthe output of the analysis tools.



3. Click the Analysis CoordinateSystem option you wish touse to save your analysisresults into either the coordi-nate system of the inputraster or the coordinatesystem of the data frame.

4. Click OK.

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Setting the outputextentThe extent of a layer is the x,ycoordinates for the bottom-leftand the top-right corners.

You can control how the outputraster extent is determined for theInterpolation and Analysis tools.By default, the output extent isthe same as the input dataset’sextent.

You may only wish to performanalysis on the area visible in themap (‘Same As Display’), or youmay wish to make the extent thesame as another layer in the tableof contents (‘Same As Layer’).Alternatively, you can specify acustom extent (‘As SpecifiedBelow’).

Specifying an extent foranalysis results


2. Click the Extent tab.

3. Click the Analysis extentdropdown arrow and choosean option to specify theextent for all subsequentanalysis results.

4. Click OK.

Tip

Setting the Snap extentSetting the Snap extent to aspecific grid will snap all layers tothe cell registration of the specifiedgrid. All layers will share thelower left corner and cell size ofthe specified grid. Use this toresample layers to the sameregistration and cell size in orderto perform analysis.

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Setting the cell size


2. Click the Cell Size tab.

3. Click the dropdown arrow andchoose the method ofdetermining the cell size.

4. Optionally, type the number ofmap units to define the cellsize.

5. Optionally, type the number ofrows and the number ofcolumns to define a cell size.

6. Click OK.

Setting the outputcell sizeYou can control the default sizeof the cells in your output rasters.By default, the output cell size isthe same as the input datasets cellsize. You can change the outputcell size to be the cell size of adataset in the current scene ormap or a cell size that you define.

Exercise caution when specifyinga cell size finer than the inputgrids. No new data is created;cells are interpolated usingnearest-neighbor resampling. Theresult is as precise as the coarsestinput.

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Overriding the default cellsizeEven if you’ve set a particular cellsize on the Options dialog box, youcan override the cell size for aparticular analysis tool by settingthe cell size on the tool.

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TINs are usually created from a combination of vector datasources. You can use point, line, and polygon features as inputdata for a TIN. Some of these input features should havez-values, though not all of the features need z-values. The inputfeatures to a TIN may also contain integer attribute values thatare preserved in the resulting TIN features. These may be used toindicate the relative accuracy of different input data or to identifyfeatures, such as roads or lakes.

Building a TIN

You can create a TIN all at once from one or more kinds of inputdata, you can create it in stages, or you can add data to refine anexisting TIN. TINs are made from mass points, breaklines, andpolygons. Mass points are point height measurements; theybecome nodes in the network. Mass points are the primary inputinto a TIN; they determine the overall shape of the surface.

Creating TIN surfaces from vector data

Mass points, categorized by height attribute

Breaklines

TINs allow you to model heterogeneous surfaces efficiently byincluding more mass points in areas where the surface is highlyvariable and fewer in places where the surface is less variable.

Breaklines are lines with or without height measurements. Theybecome sequences of one or more triangle edges.

Breaklines typically represent either natural features, such asridgelines or streams, or built features, such as roadways. Thereare two kinds of breaklines: hard and soft.

Hard breaklines represent a discontinuity in the slope of thesurface. Streams and road cuts could be included in a TIN as hardbreaklines. Hard breaklines capture abrupt changes in a surfaceand improve the display and analysis of TINs.

Soft breaklines let you add edges to a TIN to capture linearfeatures that do not alter the local slope of a surface. Study area


Clip polygon

boundaries could be included in a TIN as soft breaklines tocapture their position, without affecting the shape of the surface.

Polygons represent surface features with area—such as lakes—orboundaries—also called hulls—of separately interpolated areas.

The graphic on the left shows a TIN created from mass points; the graphicon the right shows a TIN of the same area created from mass points andbreaklines.

Replace polygons set the boundary and all interior heights to thesame value. A replace polygon could be used to model a lake oran area on a slope excavated to a level surface.

Fill polygons assign an integer attribute value to all triangles thatfall within the fill polygon. The surface height is unaffected, andno clipping or erasing takes place.

Hulls could define the shores of individual islands in anarchipelago, or the boundary of a study area.

There are four polygon surface feature types: clip polygons, erasepolygons, replace polygons, and fill polygons.

Clip polygons define a boundary for interpolation. Input data thatfalls outside of the clip polygon is excluded from theinterpolation and analysis operations—for example, contouringor volume calculations.

Erase polygons define a boundary for interpolation. Input datathat falls within the erase polygon is excluded from theinterpolation and analysis operations—for example, contouringor volume calculations.

Polygon features are integrated into the triangulation as closedsequences of three or more triangle edges.

Including breaklines and polygons in a TIN gives you morecontrol over the shape of the TIN surface.

To get a sense of the difference that breaklines can make in aTIN, compare the surface created from mass points alone to thesurface created from mass points and breaklines.


Building a TINTINs are often created from agroup of vector data sources. Youcan use point, line, and polygonfeatures as input data for a TIN.Some of these input featuresshould have z-values, though notall of the features need z-values.

You can create a new TIN inArcMap or ArcScene. You canuse features that are in the mapor scene, or you can navigate tofeature classes that aren’t on themap to include them in a TIN.

Creating a TIN

1. Click 3D Analyst, point toCreate/Modify TIN, and clickCreate TIN From Features.

2. Check the features that youwant to use in building yourTIN.

You can use the browsebutton beside the Layers listto navigate to other featureclasses to include in the TIN.

3. Click the dropdown arrowand choose the Heightsource field.

You can choose shapegeometry if the features have3D geometry.

4. Click the dropdown arrowand choose how the featuresshould be incorporated intothe TIN—as mass points,breaklines, or polygons.

5. Optionally, click thedropdown arrow and choosethe Tag value field if you wishto tag the TIN features with avalue from the input features.

6. Repeat steps 2 through 5 foreach input feature class.

7. Type a name for the TIN.

8. Click OK.

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Adding features to a TIN

1. Click 3D Analyst, point toCreate/Modify TIN, and clickAdd Feature to TIN.

2. Check the features that youwant to add to the TIN.

You can use the Browsebutton beside the Layers listto navigate to other featureclasses to include in the TIN.

3. Click the dropdown arrow andchoose the Height sourcefield.

You can choose shapegeometry if the features have3D geometry.

4. Select how the featuresshould be incorporated intothe TIN—as mass points,breaklines, or polygons.

5. Optionally, click the dropdownarrow and choose the Tagvalue field if you wish to tagthe TIN features with a valuefrom the input features.

6. Repeat steps 2 through 5 foreach input feature class.

7. Click OK.

Tip

Adding the selectedfeatures to a TINYou can add features to refine aTIN that has already been created,rather than re-creating the TINfrom scratch. If a feature class hassome features selected, only thosefeatures will be included in theTIN.

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Creating a TINfrom a rasterYou can convert a raster surfaceto a TIN for use in surfacemodeling or to simplify thesurface model for visualization.Converting to a TIN can alsoallow you to enhance yoursurface model by adding featuressuch as streams and roads thatare not represented in the originalraster.

When you convert a raster to aTIN, you need to specify thevertical accuracy of the outputTIN with respect to the originalraster. 3D Analyst will select thesubset of points needed toachieve this level of accuracy.

Converting a raster to aTIN

1. Click 3D Analyst, point toConvert, and click Raster toTIN.

2. Click the dropdown arrow andclick the raster that you wantto convert to a TIN.

3. Type a vertical accuracy forthe TIN.

4. Optionally, check the box tolimit the number of pointsadded to the TIN in pursuit ofaccuracy.

5. Optionally, type the maximumnumber of points to add tothe TIN in pursuit of accuracy.

6. Type a name for the OutputTIN.

7. Click OK.

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What is the verticalaccuracy?The vertical accuracy is themaximum number of units that theTIN surface may differ from thecell center heights of the inputraster. Specifying a low numberresults in a TIN that preservesmore of the detail of the rastersurface. A higher number willresult in a more generalizedrepresentation of the surface.

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Creating a rasterfrom a TINYou can convert a TIN to a rasterto use in surface modeling or toextract slope or aspect informa-tion from the TIN.

Converting a TIN to araster

1. Click 3D Analyst, point toConvert, and click TIN toRaster.

2. Click the dropdown arrow andclick the TIN that you want toconvert to a raster.

3. Click the Attribute dropdownarrow and click the attributeof the TIN that you want tosave as a raster.

You can choose from eleva-tion, aspect, slope in percent-age, and slope in degrees.

The TIN must have alreadybeen symbolized by theattribute in your scene ormap.

4. Optionally, set a Z factor.

5. Optionally, type the Cell sizefor the raster.

6. Type a name for the Outputraster.

7. Click OK.

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What is the Z factor?The Z factor is used to convert thez units to the same scale as the xand y units, if they are different.

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IN THIS CHAPTER

107

Managing 3D data 4• ArcCatalog basics

• Previewing 3D data

• The camera, the observer, and thetarget

• Displaying 2D data in 3D

• Starting ArcScene from ArcCatalog

• Creating a new 3D feature class

ArcCatalog allows you to manage your 3D data in the same way that youmanage all of your other GIS data. You can use ArcCatalog to organize yourwork—copy, paste, move, and delete 3D data in the Catalog tree using dragand drop, commands, or shortcut keys. You can use the Preview tab to see aplanimetric preview of your 3D data with the Geography option or preview itin 3D using the 3D View option. You can create 3D layers of 3D and 2Ddata and assign 3D viewing properties—for example, you can set the baseheights and extrusion expressions for features with z-values stored in anattribute. You can also control how a 3D layer is rendered during scenenavigation, and you can specify whether or not features are shaded basedon their position relative to a light source. In addition, you can createmetadata, including perspective view thumbnail graphics, for your data.


ArcCatalog basics

ArcCatalog lets you organize your data in an expandable treeview. You can view the selected item in the Catalog tree indifferent ways, using the tabbed view area to the right of the tree.

The Contents tab lets you see the contents of an item in the tree.The Preview tab lets you see the data contained in the selecteditem. The Metadata tab lets you see the selected item’s metadata.

Large Icons

List Details

Thumbnails

Catalog tree and contents of a folder connection

Use the Contents tab and the Catalog tree to browse and manageyour data.

Previewing data

Often, viewing your data in the Contents tab shows you all youneed to find the right data for a scene or map. Sometimes, though,you need more information. You can explore your data in thePreview tab. As with the Contents tab, you can control how youpreview data.

Large Icons

List Details

Thumbnails

Browsing the Catalog’s contents

When you select items—for example, folders, databases, orfeature datasets—in the Catalog tree, the Contents tab lists thecontents of each item. You can expand items that contain otheritems—for example, folders—and see their contents in the tree aswell. Items such as scene documents, maps, layers, and tablesdon’t contain other items; when you select them in the Catalogtree, the Contents shows the name and type of the object and athumbnail if one has been created.

You can display the Contents list in several ways. To change itsappearance, use buttons on the Standard toolbar.

MANAGING 3D DATA 109

You can draw geographic data with the Geography view. You canalso examine the attributes of feature data or the contents of anyother table with the Table view. Use the dropdown list at thebottom of the Preview tab to choose how you want to previewyour data.

This set of tools enables you to navigate around your data in 3D,query the features in your data, and create perspective viewthumbnail snapshots of your data.

Using metadata

Before you decide to use a data source in a map, you may want tolearn more about it. Metadata is background information that letsyou make better decisions about what data to use and how to useit. You can view metadata in ArcCatalog using the Metadata tab.

Metadata usually contains documentary information about whythe data was created, who created it, and how accurate the data

Metadata view

3D Analyst also gives you another way to preview your data—the 3D View preview—and a new toolbar that you can add toArcCatalog to navigate the 3D preview.

is. This kind of information can be edited using a metadata editorin ArcCatalog. Metadata also contains information about theproperties of the data—for example, the attributes stored for3D View preview

Geography and table previews—the Z in the Shape field indicates ageometry that contains z-values.


features or the coordinate system of the data. ArcCatalogautomatically maintains this information for you.

You can change the way you view an item’s metadata bychoosing a different stylesheet from the dropdown list on theMetadata toolbar.

Metadata viewed with the FGDC FAQ stylesheet

Search for data with metadata containing the word elevation.

Search

When you’ve found the data you want to use, ArcCatalog letsyou drag it directly onto a map or scene document or create alayer that specifies how the data should be symbolized andrendered in 2D or 3D.

You can also use the ArcCatalog Search tool to search for databased on information in the metadata.

The Search tool dialog box contains four tabs that allow you tosearch for data that satisfies various conditions.


Previewing 3DdataWhen the selected item in theCatalog tree contains geo-graphic data, you can previewthat data without having tocreate a map or 3D Scene. For aplanimetric view of your data,choose Geography from thePreview dropdown list on thePreview tab. For a perspectiveview, choose 3D View. In orderto view data in 3D, you willneed to enable the 3D Analystextension.

The 3D View tools allow you tonavigate around your data in3D. Some of these tools are liketools that you use in ArcMapand ArcCatalog to pan andzoom in 2D. Other tools are u

Navigating in 3D

1. Click the Navigate button onthe 3D View toolbar.

The Navigate tool allows youto rotate the data in 3D, tozoom in and out, and to panthe data.

2. Click on the data and drag itto the right.

When you click on the dataand drag to the right, yourotate the data counterclock-wise around the z-axis.

3. Right-click on the 3D dataand drag down.

When you right-click on thedata and drag down, youzoom in to the data. u

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Why does my data look flatin 3D View preview?TINs and feature classes withz-values embedded in theirgeometry—for example, PointZ,PolyLineZ, PolygonZ, andMultipatch shapes—will beautomatically rendered in 3D whenyou select 3D View. Rasters and 2Dfeature classes will be rendered asthough they rest on a flat surface.You can create layers that specify3D rendering properties for alltypes of data, and the layers will berendered in 3D.

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4. Click both mouse buttons—orthe center button on a three-button mouse—and drag thedata to the right.

Clicking both buttons anddragging the data pans thedata.

5. Click on the data and dragup.

Clicking and dragging thedata up lowers your viewingposition relative to the data.


The data returns to theoriginal extent and viewposition.

Tip

Seeing the entire datasetIf you want to see a dataset’s entirecontents after zooming andpanning around it, click the FullExtent button on the 3D Viewtoolbar.

specialized for 3D perspectiveviewing.

You use the same tools fornavigating in ArcScene.

The Navigate tool combines thefunctions of several of the othertools.

Clicking the left, right, andcenter mouse buttons anddragging up, down, left, or rightlets you rotate the 3D view,zoom in and out, and panacross the view.

You can also use the 3Dpreview to preview a scenedocument before you open it inArcScene.

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Centering

1. Click the Center on Targettool.

2. Click the location that youwant to occupy the center ofthe 3D view.

The camera, theobserver, and thetargetYou view a scene through aviewer’s camera. A camera’slocation in a scene is defined bythe observer property. Thepoint at which the camera isdirected is called the target.When you navigate through ascene, you are actually movingthe observer in conjunctionwith the target. u

The point you clicked is the new center of the view.

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Centering shortcutYou can center on a target whileusing the Navigate tool. Press theCtrl key and click at the locationwhere you want to center the scene.

Tip

Why change the center ofthe view?By default, the center of the view isthe center of the data. The Naviga-tion tool, the Zoom In and ZoomOut tools, and the field of viewtools all change the view of the datarelative to the current center of theview. If you want to zoom in to seea particular area, centering on itfirst will prevent it from zoomingout of your field of view. Centeringon a point also allows you to rotatethe view around it.


Zooming to a target

1. Click the Zoom to Target tool.

2. Click the location that youwant to zoom to.

Tip

Zooming shortcutYou can zoom to a target whileusing the Navigate tool. Press theCtrl key and right-click to zoom toa location.

When you center on the cameratarget, the point you clickmoves to the center of the view.When you zoom to the target,the view zooms to the point youclick. u

The view zooms in to the point you clicked.

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Setting the cameraobserver

1. Click the Set Observer tool.

2. Click the location that youwant to zoom to.

When you set the cameraobserver, the view zooms to thepoint you click while pointing atthe target. You can use the SetObserver and the Center onTarget tools to define how youwant this to happen. Anytimeyou use the Set Observer tool,the camera will point at thecurrent target. To point thecamera at a target that youchoose, use the Center onTarget tool first. Then whenyou set the camera observer,the camera will point toward thetarget you defined. The camera,the observer, and the target areused in the 3D view ofArcCatalog, as well as in theperspective view of ArcScene.

Tip

Using the camera tools inArcSceneThe Center on Target, Zoom toTarget, and Set Observer tools arealso available on the Navigationtoolbar in ArcScene.

Tip

Set observer shortcutYou can set the observer whileusing the Navigate tool. Press theCtrl key and middle-click to zoomto a location.

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The view zooms to the point you clicked, honoring the target.


Creating a 3D thumbnail

1. Navigate the 3D view to theperspective that you’d like toshow in a thumbnailsnapshot.

2. Click the Create Thumbnailbutton.

3. Click the Metadata tab.

The 3D thumbnail appears.

Tip

Viewing thumbnails in theContents tabIf you create a thumbnail image ofyour data, it will be shown in theContents tab when you chooseThumbnail view.

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The 3D thumbnail appears in the metadata.

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Displaying 2Ddata in 3D2D data can be viewed in 3D ifyou create a layer and set its 3Dviewing properties. You canassign z-values to featuresbased on an attribute, aconstant, or an expression. Youcan also specify a surface fromwhich to derive the z-values ofthe features.

3D Analyst adds three tabs tothe Layer Properties dialog box;these tabs allow you to modifyhow a layer is rendered in 3D.The tabs are called BaseHeights, Extrusion, andRendering. Most of the time, ifyou want to create a layer thatyou can preview in 3D, you’llset the height of the features inthe layer using the BaseHeights tab. Sometimes youmay want to extrude features upor down from the base height—for example, if you want tocreate lines that show thedepths of well point features.You can set how features areextruded on the Extrusion tab. Ifyou want to shade features inyour layer based on a lightsource, you can set thatproperty of a layer from theRendering tab. This tab alsolets you fine-tune how yourdata is displayed while you arenavigating.

Creating a layer

1. Right-click the data sourcefrom which you want tocreate the layer.

2. Click Create Layer.

3. Navigate to the folder inwhich you want to save thelayer.

4. Type a name for the layer file.

5. Click Save.

The layer file is now an itemin the Catalog.

Setting layer properties

1. Right-click the layer.

2. Click Properties.

You can use the LayerProperties dialog box to setmany properties of the layerin addition to the 3D BaseHeight, Extrusion, andRendering properties.

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Setting base heightsusing an attribute


2. Click the option to Use aconstant value or expressionto set heights for layer.

3. Click the Calculate button.

4. Double-click the field that willprovide the z-value for thefeatures.

You can create anexpression, such as [contour]* 3.28, to set the z-values aswell.

5. Click OK.

6. Click OK on the LayerProperties dialog box.

The 2D features are nowdrawn in 3D using theattribute that you selected asthe z-value.

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Setting base heightsusing a surface


2. Click the Browse button.

3. Navigate to a surface.

4. Click the surface.

5. Click Add.


The 2D features are nowdrawn in 3D using thesurface that you selected toprovide the z-value.

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Extruding features


2. Optionally, type a constantheight to which all featureswill be extruded.

3. Optionally, click the CalculateExtrusion Expression button.

4. Optionally, click the field thatyou want to use in theextrusion expression. You canbuild complex extrusionexpressions using functionsand algebraic expressions.

5. Optionally, click Load andbrowse to a previously savedextrusion expression.

6. Click OK.

7. Click the dropdown list tochoose how you want theextrusion expression applied.

8. Click OK.

The 2D features are nowextruded using the constantor expression.

Tip

What is extrusion?Extrusion extends featuresvertically from a given base heightto the height that you specify. Pointsbecome vertical lines, lines becomewalls, and polygons becomeblocks.

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StartingArcScene fromArcCatalogYou can start ArcScene fromArcCatalog by double-clickinga scene document or by clickingthe Launch ArcScene button onthe 3D View Tools toolbar.

Opening an existingscene from ArcCatalog

1. Navigate to the scene thatyou want to open.

You can use the Preview taband 3D View tools to previewthe scene before you open it.

2. Double-click the scene in theCatalog tree.

Opening a new scenefrom ArcCatalog

1. Click the ArcScene button onthe 3D View Tools toolbar.

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Creating a new3D feature classYou can create new emptyfeature classes in ArcCatalog tohold the 3D feature data thatyou create with the 3D Analystgeometry interpolation tools inArcMap. These tools will create3D graphics by default, but youcan use them while editing a 3Dfeature class to create 3Dfeatures. For more informationabout creating feature classesand shapefiles, see UsingArcCatalog.

Creating an empty 3Dfeature class or shapefile

1. Right-click in the locationwhere you want to create thenew shapefile. Point to Newand click Shapefile.

If you want to create ageodatabase feature class,navigate to an existinggeodatabase and clickFeature class.

2. Type a name for the newshapefile.

3. Click the Feature Typedropdown arrow and click thetype (geometry) of featurethat you want to create—forexample, point, polyline,polygon.

4. Optionally, click Edit to definethe spatial reference for thefeatures.

5. Click the check box toindicate that the featurecoordinates will containz-values.

6. Click OK.

The shapefile is created. Youcan right-click it in theCatalog tree, click Properties,and add attributes if you wantto store attributes for the 3Dfeatures. You do not need toinclude a height attribute, asthe z-values will be stored inthe feature geometry.

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Displaying surfaces 5• Displaying raster surfaces in 3D

• Displaying raster surfaces

• Symbolizing areas with unknownvalues

• Displaying TIN surfaces

• Making a layer transparent

• Shading a layer

ArcScene and ArcMap give you a wide variety of ways to symbolize anddisplay surfaces. Because of the differences between rasters and TINs, youhave different options for symbolizing them.

You can classify the data in continuous rasters, stretch them to improvecontrast, and display categorical rasters with colors to represent theirunique values. For multiband rasters, such as satellite images and someaerial photographs, you can display the raster as a red–green–blue (RGB)composite or as a single-band stretched image. You can render cells withno data and background cells in different ways.

ArcScene and ArcMap let you show the elevation of TIN surfaces or theaspect or slope of each TIN facet. You can also show the nodes and edgesof the TIN in several different ways.

You can make all surfaces transparent and add depth and realism to asurface by shading it based on its position relative to a light source.


Displaying rastersurfaces in 3DIn ArcScene, you can create 3Drepresentations of raster surfacesby setting the base height from araster or TIN surface. You canuse this technique to visualizeterrain surfaces, show remote-sensing images in perspective, orcreate abstract visualizations ofother surface data such aschemical concentrations orpopulation densities.

If you drape a raster over a rastersurface, you can change theresolution of the base surface; thebase surface is usually resampledto a lower resolution in order toincrease the drawing speed. ClickRaster Resolution to set theresolution of the base surface.

Draping a raster on asurface

1. In the table of contents, right-click the raster layer that youwant to drape over a surfaceand click Properties.


3. Click the button to Obtainheights for layer from surface.

If you want to use a surfaceother than the current rasterlayer, either select one of thesurfaces in the scene byclicking the dropdown arrowor click the Browse buttonand navigate to anothersurface.

4. Click OK.

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DISPLAYING SURFACES 125

Displaying rastersurfacesYou can display rasters bygrouping their values into anumber of classes, by stretchingthe values to enhance contrast, orby assigning each unique value inthe raster to a color.

How you display a raster dependson the type of data that itcontains and what you want toshow. Some rasters have apredefined color scheme, but forothers, ArcMap and ArcScenewill choose an appropriatedisplay method that you canadjust as needed. You can changedisplay colors, group data valuesinto classes, or stretch values toincrease visual contrast. Formultiband rasters, you canchoose three bands to displaytogether in an RGB composite.This drawing method oftenimproves your ability todistinguish features inmultispectral images.

Drawing rasters thatrepresent continuoussurface data withseparate classes

1. In the table of contents, right-click the raster layer that youwant to show by groupingvalues into classes and clickProperties.


3. Click Classified.

4. Click the Classes dropdownarrow and click the number ofclasses you want.

5. Optionally, click Classify andchoose the classificationmethod you want to use.

6. Click the Color Rampdropdown arrow and click acolor ramp.

7. Click OK.

Tip

Why don’t I see the optionto use unique values?You can only draw data in integerrasters with unique values.Continuous data can be classified,drawn using a stretch, or—formultiband rasters—drawn as anRGB composite image.

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The continuous surface is drawn with different colors for each class.


Drawing rasters thatrepresent continuoussurface data with acontinuous color ramp

1. In the table of contents, right-click the raster layer that youwant to show with a continu-ous color ramp.


3. Click Stretched.

4. Optionally, click the ColorRamp dropdown arrow andclick a color ramp.

5. Click OK.

Tip

Continuous rastersMost rasters that representsurfaces contain continuousvalues, whether the surface valuesrepresent elevation, temperature,or concentration of a chemical. Itis often useful to display continu-ous surfaces with a continuousgrayscale or color ramp. TheStretched option maps the low andhigh values in the raster to a0–255 intensity scale. You canchange the way that the values aremapped by changing the type ofstretch used.

The continuous surface is drawn with a continuous color ramp.

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Drawing thematic rastersthat represent uniquecategories, such as landcover

1. In the table of contents, right-click the raster layer that youwant to show using uniquecategories and clickProperties.


3. Click Unique Values.

4. Click the Value Fielddropdown arrow and click thefield you want to map.

5. Click the Color Schemedropdown arrow and click acolor scheme.

If your raster has a colormap,click Default Colors to revertto colors specified in thecolormap.

6. Optionally, click a label andtype in a more descriptivename.

7. Click OK.

Tip

Categorical rastersClassifying remotely sensedimagery, converting vector data toraster, and running certainanalysis procedures can producerasters that contain categoricalvalues. In these cases, the valuesmay be highly discontinuous andpatchy, in comparison to thecontinuous and, generally,smoothly varying values ofsurfaces. Categorical rasters areusually drawn with Unique Values.

The categorical raster is drawn with unique colors for each value.

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Stretching a raster toimprove the visualcontrast

1. In the table of contents, right-click the raster layer that youwant to increase the visualcontrast of and clickProperties.


3. Click Stretched.

4. Click the Color Rampdropdown arrow and click acolor ramp.

5. Click the Stretch Typedropdown arrow and click thestretch you want to apply.

6. Optionally, click Histogram tomodify the stretch settings.

7. Optionally, if the rastercontains a background orborder around the data thatyou want to hide, checkDisplay Background Valueand set the color to No Color.

The cells will displaytransparently.

8. Click OK.

Tip

What is a stretch?A stretch increases the visualcontrast of a raster. You mightapply a stretch when your rasterappears too dark or has littlecontrast. Different stretches willproduce different results in theraster display. You can experimentto find the best one for a particularraster.

The image raster is drawn with a contrast stretch.

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Changing the band colorassignments for amultiband raster

1. In the table of contents, right-click the raster layer and clickProperties.


3. Click RGB Composite.

4. Optionally, uncheck bands toturn them off.

5. Click the Red, Green, andBlue dropdown arrows andselect the bands of the rasterthat will be displayed in red,green, and blue.

6. Click OK.

Tip

Why do I only see threebands when I added a five-band raster?When you add a multiband rasterto a map or scene, you see an RGBcomposite image made from threeof the bands. You can select whichthree or fewer of the bands will bedrawn using the Red, Green, andBlue color elements. By default,the first three bands are mapped toRed, Green, and Blue, but you canchange the band mapping for agiven image or for all images thatyou add.

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Adding a single band of amultiband raster

1. Navigate to the raster.

2. Expand the raster to view theindividual bands.

3. Select a single band and clickAdd.

The band is added as asingle-band raster.

Turning bands on and offin a multiband raster

1. Click the color square besidethe band you want to turn off.

2. Click Visible to uncheck it.

The band is turned off.

Tip

Changing band colorsYou can quickly change the colorassignments of the bands in amultiband raster. In the table ofcontents, click the color square—Red, Green, or Blue—and click theband in the multiband raster thatyou want to display using thatcolor.

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Setting the default colorband assignments formultiband rasters


2. Click the Raster tab.

3. Click the up and down arrowsto select the bands in theraster that will be rendered inRed, Green, and Blue.

4. Click OK.

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Symbolizingareas withunknown valuesSometimes rasters contain cellswhere there is no measurement ofthe surface. In grids these areusually represented as NoDatavalues. In remote-sensing imagesthere are often triangular orlinear border areas within theraster but outside the area forwhich image values wererecorded. These are often blackand are called Backgroundvalues.

You can control the way thatareas of NoData and Backgroundare displayed. The default is todisplay NoData with no color.

Setting the NoData orBackground display color

1. In the table of contents, right-click the raster layer and clickProperties.


3. Check the box to DisplayBackground Value.

4. Optionally, type a value todefine the raster’s Back-ground color.

5. Click the Background colorselector dropdown arrow andclick a color—or no color.

6. Click the Display NoData ascolor selector dropdownarrow and click a color—or nocolor.

7. Click OK.

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Displaying TINsurfacesTINs are made up of triangularfacets and the nodes and edgesthat make up the triangles. Theymay also contain breaklines—lines that follow sets of edgesthat play important roles indefining the shape of thesurface—such as ridgelines,roads, or streams.

You can display one type of TINfeature in a map or scene—forexample, just the triangles—orall of the TIN features. You canalso symbolize each type offeature in different ways.

Drawing TIN faces byelevation

1. In the table of contents, right-click the TIN.


3. Click Elevation.

4. Optionally, click the ColorRamp dropdown arrow andclick a new color ramp.

5. Optionally, click the Classesdropdown arrow and choosethe number of classes.

6. Click OK.

The TIN is drawn with different colors for each elevation class.

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Drawing TIN faces byaspect



3. Uncheck Elevation—or anyother TIN face renderer thatis checked.

4. Click Add.

5. Click Face aspect withgraduated color ramp.

6. Click Add.

7. Click Dismiss. u

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8. Click OK.

The TIN faces are renderedwith colors to indicate thedirection that they face.

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The TIN is drawn with different colors for each triangle’s aspect class.


Drawing TIN faces byslope



3. Uncheck Aspect—or anyother TIN face renderer thatis checked.

4. Click Add.

5. Click Face slope withgraduated color ramp.

6. Click Add.

7. Click Dismiss. u

Tip

Changing the slope of aTIN surfaceTIN triangle slope values arecalculated, not stored in the TIN. Ifyou change the z unit conversionfactor, the slopes of each TIN facewill be recalculated.

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8. Click the Color Rampdropdown arrow and select acolor ramp.

9. Click OK.

The TIN faces are renderedwith colors to indicate theslope of the terrain.

The TIN is drawn with graduated colors for each triangle’s slope class.

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Tip

What are tag values?TIN nodes and triangles can betagged with integer values to allowyou to store additional informationabout them. These integer valuescan be used as lookup codes—forexample, to indicate the accuracyof the input feature data source orthe land use type code for areas onthe surface.

The codes can be derived fromfields in the input feature classes.You can symbolize tagged featureswith unique values.

Drawing TIN faces by tagvalue




4. Click Add.

5. Click Face tag value groupedwith unique symbols.

6. Click Add.

7. Click Dismiss. u

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8. Click Add All Values.

9. Click OK.

The TIN is drawn with different colors for each triangle’s tag value.

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Drawing TIN nodes byelevation




4. Click Add.

5. Click Node elevation withgraduated color ramp.

6. Click Add.

7. Click Dismiss. u

Tip

How else can I display TINnodes?You can also display TIN nodes bytag value or all nodes using thesame symbol.

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8. Click the Color Rampdropdown arrow and select acolor ramp.

9. Click OK.

The TIN nodes are renderedwith colors to indicate theirelevation.

In this example, you can alsosee the Soft and Hard edges,which are on by default, if theTIN has them.

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Drawing TIN edgesgrouped with a uniquesymbol



3. Uncheck Elevation.

4. Click Edge types.

By default, only the type 1and 2 (Hard and Soft) edgesare displayed.

5. Click Add All Values.

6. Click OK.

Tip

How else can I display TINedges?You can also display all TIN edgeswith the same symbol, and you canadd and remove individual edgetypes from the display using theAdd Values and Remove Valuesbuttons.

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Making a layertransparentYou can make raster, TIN, andfeature layers transparent inscenes and maps. You can usetransparent layers to visualizedata that is scattered above andbelow a reference plane, comparetwo surfaces, and show terrainand subsurface features at thesame time.

1. In the table of contents, right-click the layer and clickProperties.


3. Type a value in theTransparent box.

4. Click OK.

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Tip

How else can I make alayer transparent?You can use the Adjust Transpar-ency tool on the Effects toolbar inArcMap or the 3D Effects toolbarin ArcScene to set the transparencyfor a layer.


Shading a layerYou can shade raster, TIN, andfeature layers relative to theposition of a light source inscenes and maps. You can useshading to increase theperception of depth in the sceneand to enhance details of thetopography.


2. Click the Rendering tab.

3. Check the box to Shade arealfeatures relative to thescene’s light position.

The option to Use smoothshading if possible is checkedby default. This minimizes theshading of small surfacevariations to create asmoother-looking shadedsurface.

4. Click OK.

Tip

Changing the light sourceYou can change the light sourcefor a scene or map to enhance theshading on a surface. Click theIllumination tab on the SceneProperties or Data FrameProperties dialog box for controlsthat let you change the light sourceposition.

Tip

TIN face shadingYou turn shading on or off forindividual TIN face renderers byclicking the Symbology tab,clicking the TIN face rendered, andchecking or unchecking the Showhillshade illumination check box.

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Analyzing surfaces 6• Querying surface values

• Understanding the shape of asurface

• Deriving slope and aspectinformation from a surface

• Creating contours

• Analyzing visibility

• Deriving hillshade from a surface

• Determining height along a profile

• Finding the steepest path

• Calculating area and volume

• Reclassifying your data

• Converting surfaces to vectordata

• Creating 3D features

Surfaces—fields that contain an infinite number of points—typicallyembody a great deal of information. You may want to simply view thesurface, which is a great way to understand the surface in general, or youmay be interested in specific information about parts of the surface. Forexample, you might want to know the altitude, temperature, atmosphericpressure, or concentration of a pesticide at a given point on the surface. Youmight want to know whether an observer at point A can see point B or howsteep a proposed trail would be. You might be interested in the capacity of aproposed reservoir or the amount of material in a ridge. Or, you might beinterested in general information about the surface’s shape that is notimmediately apparent by simply viewing the surface. For example, you maywant to know what points are at the same elevation, what parts of thesurface face the same direction, and where the concentration of a chemicalor the land surface declines most precipitously.

In addition to letting you view surfaces in perspective and symbolize themin different ways, 3D Analyst gives you tools to get more information aboutspecific points on a surface and lets you derive general information, such asslope, aspect, and contours, from the whole surface. 3D Analyst also givesyou tools to convert surface data into vector data for analysis with othervector data sources.


Querying surfacevaluesSometimes just looking at 3Ddata is not enough. You oftenneed to query data or derive newdata to solve problems.3D Analyst lets you explore thedata on a map or in a scene andget the information you need.

You can click surfaces or featuresto find out what they are. Whenyou click to get informationabout a TIN, you can find out theelevation, slope, and aspect ofthe point where you clicked. Ifthe TIN feature has a tag value, itwill be shown as well. When youclick a raster surface, you see theelevation value at the point.When you click a feature, yousee all of the attributes of thefeature.

Identifying features orcells by clicking them

1. Click the Identify button onthe Tools toolbar in ArcSceneor ArcMap or on the 3D ViewTools toolbar in ArcCatalog.

2. Click the mouse pointer overthe feature or cell you want toidentify.

Displaying Map Tips forsurfaces

1. In the ArcMap table ofcontents, right-click the layerfor which you want to displayMap Tips and clickProperties. u

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ANALYZING SURFACES 147


3. Check Show Map Tips.

4. Click OK.

5. Move the mouse pointer overa TIN facet or raster cell tosee the Map Tip.

Tip

Displaying Map Tips forfeaturesYou can display Map Tips forfeature data layers. The Map Tipshows the contents of a feature’sprimary display field.

You can change the primarydisplay field by clicking the Fieldstab in the Layer Properties dialogbox, clicking the Primary displayfield dropdown arrow, thenclicking a field.

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Understanding the shape of a surface

One good way to get a general understanding of the shape of asurface is to view it in 3D. You can zoom in and out and rotatethe surface to see it from different angles. When you need toshow a surface on a printed map, it can be useful to createcontour lines to represent the surface.

Aspect is the direction a slope faces. Aspect is often used todetermine how much sun a slope will receive—for instance, tomodel how vegetation will grow, how snow will melt, or howmuch solar heating a building will receive.

Slope and aspect in rasters and TINs

Rasters and TINs model a surface’s slope and aspect in differentways. In a raster, slope and aspect are calculated for each cell byfitting a plane to the z-values of each cell and its eightsurrounding neighbors. The slope or the aspect of the planebecomes the slope or aspect value of the cell in a new raster. In aTIN, each triangle face defines a plane with a slope and anaspect. These values are quickly calculated, as needed, when youquery or render the faces.

Hillshading surfaces

Hillshades are the patterns of light and dark that a surface wouldshow when illuminated from a particular angle. Hillshades areuseful for increasing the perception of depth in a 3D surface andfor analysis of the amount of solar radiation available at alocation.

3D perspective hillshaded view of terrain and planimetric contourline representation of the same area

Terrain slope and aspect surfaces. In the picture on the left,darker shades of red indicate steeper slopes. In the picture on theright, west-facing slopes are dark blue, and southeast-facingslopes are yellow.

3D Analyst gives you tools that let you create individualcontours or contours for a whole surface. An experienced mapreader can tell that the surface is steeper where the lines are closetogether and identify ridgelines and streams from the shape of thecontours. Contour lines can give you a feel for the shape of asurface, but they are not very useful as input for an analysis.

3D Analyst also has tools that allow for more quantitativeanalysis of the shape of a surface. Slope and aspect are two waysof quantifying the shape of a surface at a particular location.

Slope is the incline, or steepness, of a surface. It is often used inanalyses to find areas with low slopes for construction or areaswith high slopes, which may be prone to erosion or landslides.


There are two ways to hillshade a surface. One technique, whichis most useful for adding depth for 3D visualization, is to turn onshading for the layer in ArcScene using the Rendering tab in theLayer Properties dialog box. This shades the layer—any surfaceor areal 3D feature layer—on the fly, using the scene’sIllumination settings. Hillshading is on by default for TINs. Youmust turn it on for rasters because not all rasters are surfaces.

Deriving contour lines from rasters and TINs

Contours are lines that connect all contiguous locations with thesame height—or other—value in the input grid or TIN. There aretwo ways to create contours with 3D Analyst. One way is to clickthe surface with the contour tool. This creates a single contourline, which exists as a 3D graphic in a scene or map. The otherway to create contours is to use the Contour surface analysiscommand. This creates a series of contours with a given contourinterval for the whole surface. These contours are saved as afeature class with a height attribute.

When you create contours from a grid, the contouring functioninterpolates lines between the cell centers. The lines seldom passthrough the cell centers and do not follow the cell boundaries. Incontrast, when you create contours from a TIN, the functioninterpolates straight lines across each triangle that spans thecontour value, using linear interpolation between the edgeendpoints to determine where the contour crosses the face.3D perspective view of terrain without and with hillshading

2D elevation raster, transparent hillshade raster, and shaded relief map

Contours created from a raster surface and from a TIN surface

The second technique, which is useful as input for analyses andfor enhancing depth in 2D surfaces in ArcMap, is to use theHillshade surface analysis command in the 3D Analyst toolbar.This creates a new hillshade raster that you can make partiallytransparent and display in 2D, or 3D, with an elevation layer.


Calculating slope

What is slope?

Slope identifies the steepest downhill slope for a location on asurface. Slope is calculated for each triangle in TINs and for eachcell in rasters. For a TIN this is the maximum rate of change inelevation across each triangle. For rasters it is the maximum rateof change in elevation over each cell and its eight neighbors.

The slope command takes an input surface raster and calculatesan output raster containing the slope at each cell. The lower theslope value, the flatter the terrain; the higher the slope value, thesteeper the terrain. The output slope raster can be calculated aspercent slope or degree of slope.

Elevation grid

When the slope angle equals 45 degrees, the rise is equal to therun. Expressed as a percentage, the slope of this angle is100 percent. Note that as the slope approaches vertical (90°), thepercentage slope approaches infinity.

The slope function is most frequently run on an elevation grid, asthe following diagrams show. Steeper slopes are shaded red onthe output slope map.

0–7

8–15

16–23

24–31

32–39

40–47

48–55

56–63

64–70

71–78

High

Low

Slope map (in degrees)

Degree of slope =

θrise

run= tan θ

Percent of slope = * 100rise

run

Degree of slope = 30 45 76

Percent of slope = 58 100 375


Deriving slopefrom a rastersurfaceSometimes the elevation of apoint on a surface is lessinteresting than the slope of thesurface at that point.

You can derive new rasters thatshow the slope of surfaces to getthis information.

Slope is rapidly calculated on thefly for each triangle face in aTIN, though you can also createrasters of slope from TINsurfaces.

Deriving slope

1. Click 3D Analyst, point toSurface Analysis, and clickSlope.

2. Select the surface from whichyou want to derive a raster ofslope values.

3. Click Degree or Percent.

4. Type a Z factor. This iscalculated automatically if theinput has a defined spatialreference that includes z unitinformation.

5. Type an Output cell size.

6. Type the name of the Outputraster.

7. Click OK.Tip

Degree and percent slopeSlope can be measured in degreesfrom horizontal (0–90) or percentslope, which is the rise divided bythe run, times 100. As slope angleapproaches vertical (90 degrees),the percent slope approachesinfinity.

Tip

Why use a Z factor?To get accurate slope results, the zunits must be the same as the x,yunits. If they are not the same, usea Z factor to convert z units to x,yunits. For example, if your x,yunits are meters, and your z unitsare feet, you could use a Z factorof 0.3048 to convert feet to meters.

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Why use the aspect function?

There are many different reasons to use the aspect function. Forinstance, you may want to:

• Find all north-facing slopes on a mountain as part of a searchfor the best slopes for ski runs.

• Calculate the solar illumination for each location in a regionas part of a study to determine the diversity of life at each site.

• Find all southerly slopes in a mountainous region to identifylocations where the snow is likely to melt first, as part of astudy to identify those residential locations that are likely tobe hit by meltwater first.

• Identify areas of flat land to find an area for a plane to land incase of emergency.

What is the aspect?

Aspect is the direction that a slope faces. It identifies the steepestdownslope direction at a location on a surface. It can be thoughtof as slope direction or the compass direction a hill faces. Aspectis calculated for each triangle in TINs and for each cell in rasters.

Aspect is measured counterclockwise in degrees from 0—duenorth—to 360—again due north, coming full circle. The value ofeach cell in an aspect grid indicates the direction in which thecell’s slope faces. Flat slopes have no direction and are given avalue of -1.

Calculating aspect

0

90

135

180

270

315

N

S

EW

NW NE

SESW225

45

Flat

N

NE

E

SE

S

SW

W

NW

High

Low

Flat

N

NE

E

SE

S

SW

W

NW

The diagram below shows an input elevation grid and the outputaspect grid.


Deriving aspect

1. Click 3D Analyst, point toSurface Analysis, and clickAspect.

2. Click the dropdown arrow andclick the surface from whichyou want to derive a raster ofaspect values.

3. Type an Output cell size.

4. Type the name of the Outputraster.

5. Click OK.

Deriving aspectfrom a rastersurfaceSometimes the elevation of apoint on a surface is lessinteresting than the aspect of thesurface at that point.

To get this information, you canderive new rasters that show theaspect of surfaces.

Aspect is rapidly calculated onthe fly for each triangle face in aTIN, though you can also createrasters of aspect from TINsurfaces.

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Mapping contours

What are contours?

Contours are lines that connect points of equal value, such aselevation, temperature, precipitation, pollution, or atmosphericpressure. The distribution of the lines shows how values changeacross a surface. Where there is little change in a value, the linesare spaced farther apart. Where the value rises or falls rapidly, thelines are closer together.

Why map contours?

By following the line of a particular contour, you can identifywhich locations have the same value. By looking at the spacing ofadjacent contours, you can gain a general impression of thegradation of values.

The example below shows an input elevation grid and the outputcontour map. The areas where the contours are closer togetherindicate the steeper locations. They correspond with the areas ofhigher elevation (in white on the input elevation grid).

Elevation grid and derived contour map

Using contours in a scene

Contours are a familiar surface representation for many people,and they have many uses in a scene. You can display contourfeatures in a 3D scene by setting the base height of the contoursfrom their value in the feature table. Contours in a scene canenhance terrain visualization.

Contours superimposed on terrain surfacemodel

Feature attribute table for contours

The attribute table of the contour features contains an elevationattribute for each contour line.


You can also create individual 3D graphic contour lines if youdon’t want contours for the whole surface. The Contour tool onthe 3D Analyst toolbar lets you create 3D graphic contour linesby clicking a surface in a scene or map.

3D graphic contour copied from a scene into a map

3D graphic contours marking lines of equalelevation

You can copy 3D contour graphics between ArcScene andArcMap to establish a visual correspondence between a 3Dterrain representation in a scene and a 2D representation on amap.

Contourtool

ArcScene 3D Analyst toolbar

ArcMap 3D Analyst toolbar

You can use individual graphic contours to quickly find points ofequal value in a scene. For example, you can use them to markthresholds in the concentration of a chemical or fill lines in areservoir.


Deriving contourlines from asurfaceContour lines are a familiar wayof representing surfaces on maps.A contour is a line through allcontiguous points with equalheight or other values. Whilecontours may be readily inter-preted by people, they are a poorsurface model for computers.

You can create contour lines for awhole surface, or you can click apoint and create a single contourthat passes through it.

Deriving contours

1. Click 3D Analyst, point toSurface Analysis, and clickContour.

2. Click the dropdown arrow andclick the surface from whichyou want to derive contours.

3. Type the Contour interval.

4. Optionally, specify a Basecontour.

5. Optionally, specify a Z factor.

6. Browse to the location whereyou want to save the contoursand type a name for them.

7. Click OK.

Tip

What is the offset?The offset lets you control theposition of the minimum contour.By default, the contour tool usesthe minimum Input height tocalculate the elevation for theminimum contour. If the defaultminimum contour was 298 meters,you could use an offset of 2 toplace the minimum contour at 300.

Tip

What is the Z factor?The Z factor is used to adjust theunits of the data. For example, ifyou have data in meters, and youwant to produce contours in feet,you could use a Z factor of 3.28.

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Creating a single contour

1. Click the Contour button.

2. Click the surface at the pointwhere you want the contour.

The contour is added as a 3Dpolyline graphic. The heightof the contour is written to thestatus bar.

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Analyzing visibility

The shape of a terrain surface dramatically affects what parts ofthe surface someone standing at a given point can see. What isvisible from a location is an important element in determining thevalue of real estate, the location of telecommunication towers, orthe placement of military forces. 3D Analyst allows you todetermine visibility on a surface from point to point along a givenline of sight or across the entire surface in a viewshed.

What is a line of sight?

A line of sight is a line between two points that shows the parts ofthe surface along the line that are visible to or hidden from anobserver. Creating a line of sight lets you determine whether agiven point is visible from another point. If the terrain hides thetarget point, you can see where the obstruction is and what else isvisible or hidden along the line of sight. The visible segments areshown in green, and the hidden segments are shown in red.

While you cannot create a line of sight in ArcScene, you cancreate one in ArcMap and copy and paste it into a scene. The lineof sight is shown in the scene as a green and red 3D line graphicthat follows the surface.

What is the viewshed?

The viewshed identifies the cells in an input raster that can beseen from one or more observation points or lines. Each cell inthe output raster receives a value that indicates how manyobserver points can see the location. If you have only oneobserver point, each cell that can be seen from the observer pointis given a value of 1. All cells that cannot be seen from theobserver point are given a value of 0.

The Observer Points feature class can contain points or lines. Thenodes and vertices of lines will be used as observation points.

Why calculate the viewshed?

The viewshed is useful when you want to know how visibleobjects might be—for example, you may need to know “Fromwhich locations on the landscape will the landfill be visible if it isplaced in this location?”, “What will the view be like from thisroad?”, or “Would this be a good place for a communicationstower?”.

Line of sight created in ArcMap and copied and pasted into a 3D scene

Target

Observer

Observer height

Line of sight

When you create a line of sight, you first set the offset of theobserver and target points above the surface—the observershould always be set a little above the surface—then you click theobserver and target points, and a graphic line appears betweenthem.


In the example below, the viewshed from an observation point isidentified. The elevation grid displays the height of the land(darker locations represent lower elevations), and the observationpoint is marked as a green triangle. Cells in green are visible fromthe observation point, while cells in red are not visible.

Displaying a hillshade underneath your elevation and the outputfrom the Viewshed function gives a very realistic impression ofthe landscape and clearly indicates the locations that an observercan see from the observation point.


Creating a line ofsightA line of sight is a graphic linebetween two points on a surfacethat shows where along the linethe view is obstructed. The colorof the line indicates the locationswhere the surface is visible andwhere the surface is hidden. Thestatus bar indicates if the target isvisible or hidden.

The Line of Sight tool is onlyavailable on the 3D Analysttoolbar in ArcMap. Once you’vecreated a line of sight in ArcMap,you can copy and paste it into ascene. The line of sight appearsin a scene as a 3D line thatfollows the shape of the surface,with obstructed areas shown inred and clear areas shown ingreen.

1. In ArcMap, click the Line ofsight button on the 3DAnalyst toolbar.

2. Optionally, type an Observeroffset.

3. Optionally, type a Targetoffset.

4. Optionally, check the box tomodel curvature and refrac-tion. For this option to beenabled, the surface musthave a defined spatialreference in projectedcoordinates and definedz-units.

5. Click the surface at theobserver location, then clickthe target location.

Tip

What are the Observeroffset and Target offset?The Observer offset is the eye levelof the observer used in determin-ing what is visible from theobserver’s location. An observerwith a height of 0—the units arethe same as the surface’s z-units—will usually have a more ob-structed view than one with aheight of 1 or 10.

The Target offset is the height ofthe target point above the surface.Targets with a height of 0 are lessvisible than taller ones.

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Deriving aviewshedThe Viewshed tool lets you findthe places that can be seen fromone or more observation pointsor lines. If lines are used as input,the observation points occur atthe vertices of the lines.

The Viewshed tool creates araster that contains cells coded toindicate whether they are visibleto or hidden from the observer. Ifthere are more than one observerpoints, each visible cell in theraster shows the number ofpoints from which it is visible.

The Input surface can be a grid orTIN.

Creating a mapdisplaying the viewshed

1. Click 3D Analyst, point toSurface Analysis, and clickViewshed.

2. Click the Input surfacedropdown arrow and click theinput surface you want tocalculate the Viewshed from.

3. Click the Observer pointsdropdown arrow and click thefeature layer to use asobserver points.

4. Specify a Z factor. The defaultis 1. The Z factor is automati-cally calculated if the inputsurface has a spatial refer-ence with z-units defined.

5. Specify an Output cell size.

6. Specify a name for theOutput raster or leave thedefault to create a temporarydataset in your workingdirectory.

7. Click OK.

Tip

Using optional parametersOptional viewshed parameters—SPOT, OFFSETA, OFFSETB, andso on—will be used if they arepresent in the feature observerattribute table. For more informa-tion, search ArcGIS Desktop Helpfor viewshed.

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Using hillshading in analysis

By modeling shadow, you can identify those cells that will be inthe shadow of another cell at a particular time of day. Cells thatare in the shadow of another cell are coded 0; all other cells arecoded with integers from 1 to 255. You can reclassify valuesgreater than 1 to 1, producing a binary raster. In the examplebelow, the black areas are in shadow. The azimuth is the same,but the sun angle (altitude) has been modified.

What is the hillshade function?

The hillshade function obtains the hypothetical illumination of asurface by determining illumination values for each cell in anelevation grid. It does this by evaluating the relationship betweenthe position of the light source and the direction and steepness ofthe terrain. It can greatly enhance the visualization of a surfacefor analysis or graphical display.

By default, shadow and light are shades of gray associated withintegers from 0 to 255, increasing from black to white.

Computing hillshade

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The azimuth is the angular directionof the sun, measured from north inclockwise degrees from 0 to 360.An azimuth of 90 degrees is dueeast. The default is 315 degrees(NW).

The altitude is the slope or angle ofthe illumination source above thehorizon. The units are in degrees,from 0—on the horizon—to 90degrees—overhead. The default is45 degrees.

The light source of the hillshade tothe left has an azimuth of315 degrees and an altitude of45 degrees.

Sun angle: 45 degrees

Using hillshading for display

By placing an elevation grid on top of a created hillshade grid andmaking the elevation grid transparent, you obtain a very realisticimage of the elevation of the landscape. You can add other layers,such as roads or streams, to further increase the informationalcontent in the display.

Sun angle: 60 degrees


Deriving hillshadefrom a surfaceHillshade rasters show thehypothetical illumination of asurface, given a specified lightsource. Hillshades can be used toanalyze the intensity and durationof sunlight received at a locationon a surface. They are also usedin conjunction with elevationlayers to give depth to terrainmaps. Hillshade works on rasterand TIN layers.

You can accentuate topographicfeatures by changing the altitudeand azimuth values. Altitude isthe slope or angle of the illumi-nation source above the horizon;azimuth is its angular direction.

Creating a hillshaderaster

1. Click 3D Analyst, point toSurface Analysis, and clickHillshade.

2. Click the dropdown arrow andclick the surface from whichyou want to derive a hillshaderaster.

3. Specify the azimuth you wishto use. The default is315 degrees.

4. Specify an altitude. Thedefault is 30 degrees.

5. Optionally, check Modelshadows if you wish toinclude the shading effect ofsurrounding cells. Cells in theshadow of other cells will becoded 0.

6. Specify a Z factor. Thedefault is 1. The Z factor isautomatically calculated if theinput surface has a spatialreference with z-unitsdefined.

7. Specify an Output cell size.

8. Specify a name for theOutput raster.

9. Click OK.

Tip

Modeling shadowsCheck Model shadows to codecells 0 if they are in the shadow ofother cells.

Tip

Specifying a Z factorUse the Z factor to make thez-value units the same as the x,yunits. If your x and y units are inmeters, and your z units are in feet,you would specify a Z factor of3.28 to convert feet to meters.

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Shading a raster with ahillshade

1. Create a hillshade raster fromthe surface raster that youwant to shade (see ‘Creatinga hillshade raster’ in thischapter).

2. In the table of contents, right-click the hillshade layer andclick Properties.


4. Type a value in the Transpar-ent box to set the percenttransparency. 50% is areasonable value.

5. Click OK.

You should now see theelevation raster through thehillshade raster.

Tip

Adding depth in 2DYou can use a hillshade raster toenhance the perception of depth ina 2D raster representation ofterrain. TINs support colored andshaded relief directly, so you don’tneed to create a hillshade for them.

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Shading 3Dsurfaces in asceneShading increases the realism ofa 3D scene and improves yourability to distinguish details ofthe surface. By default, TINsurfaces are drawn usingshading, though you can turn itoff. Raster surfaces can easily beshaded, too—without the needfor creating a hillshade raster.

Shading a raster surfacein a scene

1. In ArcScene, set the baseheight of the raster to itself(see ‘Displaying rastersurfaces in 3D’ in Chapter 5).

2. Right-click the raster layer inthe table of contents and clickProperties.


4. Check the box to Shade arealfeatures relative to thescene’s light position.

The option to Use smoothshading if possible is checkedby default. This minimizes theshading of small surfacevariations, which creates asmoother-looking shadedsurface.

5. Click OK.

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Determiningheight along aprofileProfiles show the change inelevation of a surface along aline. They can help you assessthe difficulty of a trail or evaluatethe feasibility of placing a railline along a given route.

1. In ArcMap, click the Layerdropdown arrow and click thesurface that you want toprofile.

2. Click the Interpolate Linebutton.

3. Click the surface and digitizea line. When you are finished,double-click to stop digitizing.

4. Click the Profile Graphbutton.

5. Optionally, to change thelayout of the profile graph,right-click on the title bar ofthe profile graph and clickProperties.

Tip

Profiling a 3D line featureYou can also create a profile graphfor 3D line features, as well as for3D graphics. Select a 3D linefeature and click Profile Graph.

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Finding thesteepest pathYou can evaluate runoff patternson a TIN surface model by usingthe Steepest Path tool. TheSteepest Path tool calculates thedirection a ball would take ifreleased at a given point on thesurface. The ball will take thesteepest path downhill until itreaches the perimeter of thesurface model or it reaches apit—a point all surrounding areasflow into. The result is a 3Dgraphic line added to the map orscene.

You can use the Steepest Pathtool to evaluate the integrity of aTIN surface model, for example,to find paths that end unaccount-ably or meander off in a directiondifferent from runoff on theactual site. If you’re going to usethe model for runoff studies,you’ll need to correct suchanomalies.

1. Click the Steepest Path tool.

2. Click the surface at thelocation where you want thepath to begin.

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Calculating areaand volumeUse the Area and VolumeStatistics tool to calculate 2Darea, surface area, and volume.All are relative to a givenreference plane.

The 2D area of a rectangularpatch of surface model is simplyits length times its width. Thesurface area is measured alongthe slope of the surface; it takesthe variation in the height of thesurface into account. Unless thesurface is flat, the surface areawill always be greater than the2D area. You can compare thevalues for the 2D area andsurface area to get an indicationof the roughness or slope of thesurface—the larger the differencebetween the values, the rougheror steeper the surface.

The volume is the space—incubic map units—between thesurface and a reference plane setat a particular height. You candetermine the volume above theplane or below it, so you cananswer questions such as “howmuch material is between the1,200-foot contour and the top ofthis hill?” or “how much watercould be stored in this reservoirif the top of the dam is at 300meters?”

1. Click 3D Analyst, point toSurface Analysis, and clickArea and Volume.

2. Click the dropdown arrow andclick the surface for which youwant to calculate area andvolume statistics.

3. Type a height for thereference plane.

4. Click to calculate above orbelow the reference plane.

5. Optionally, type a Z factor toconvert the z units to x,y unitsif the z units of the surfaceare not the same as thex,y units.

You will get inaccurate resultsif the units are not the sameand you do not include aZ factor.

6. Optionally, check the box tosave the results to a text file.

7. Optionally, type a name forthe text file where the resultswill be saved.

8. Click Calculate statistics.

The 2D area, Surface area,and Volume will be reportedin the area below this buttonand optionally written to a textfile.

You can change theparameters and click thebutton again to repeat thecalculation.

9. Click Done.

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What is reclassification?

Reclassifying your data simply means replacing input cell valueswith new output cell values. Reclassifying continuous data intocategories is an important step in the process of transformingsurface data into vector data for analysis.

The input data can be any raster format. If you add a multibandraster, the first band will be taken and used in the reclassification.

Why reclassify your data?

There are many reasons why you might want to reclassify yourdata. Some of the most common reasons are to:

• Replace values based on new information.

• Classify certain values together for display.

• Classify certain values together for conversion to vectorformat for analysis.

• Reclassify values to a common scale.

• Set specific values to NoData or to set NoData cells to avalue.

Replacing values based on new information

Reclassification is useful when you want to replace the values inthe input raster dataset with new values. This could be due tofinding out that the value of a cell, or a number of cells, shouldactually be a different value. For example, this may happen if theland use in an area changed over time.

Grouping values together

You may want to simplify the information in a dataset. Forinstance, you may want to group together various types of forestinto one forest class or group aspect values into generalcategories, such as north-facing and south-facing slopes.

You may also want to do overlay and selection on data from asurface—for example, finding and selecting areas that have lowslope and southeast aspect. You can create the vector data for thiskind of polygon overlay and selection using reclassified slopeand aspect rasters.

Reclassifying values of a set of rasters to a commonscale

Another reason to reclassify is to assign values of preference,sensitivity, priority, or some similar criteria to a raster. This maybe done on a single raster (a raster of soil type may be assignedvalues of 1–10 that represent degree of susceptibility to erosion)or with several rasters to create a common scale of values.

Setting specific values to NoData or setting NoDatacells to a value

Sometimes you want to remove specific values from youranalysis. For example, a certain land cover type may haverestrictions—such as wetlands restrictions—that mean you can’tbuild there. In such cases you might want to change these valuesto NoData in order to remove them from further analysis.

In other cases, you may want to change a value of NoData to be avalue. For example, you might acquire new information and wantto update a value of NoData with the new value.

Reclassifying data


Reclassifyingyour dataThe Reclassify dialog boxenables you to modify the valuesin an input dataset and save thechanges to a new output dataset.

There are many reasons why youmay wish to do this, includingreplacing values based on newinformation, grouping entries,reclassifying values to a commonscale—for example, for use insuitability analysis—or settingspecific values to NoData orsetting NoData cells to a value.

The Load button enables you toload a remap table that waspreviously created by pressingthe Save button and applying it tothe input raster dataset.

The Save button enables you tosave a remap table for later use.

Tip

Changing the classes ofyour old valuesClick Classify to classify your oldvalues differently.

Click Unique to separate classes ofold values into unique values.

Tip

Replacing NoData valuesNoData values can be turned intonumeric values in the same way asyou replace any value.

Replacing values basedon new information

1. Click the 3D Analystdropdown arrow and clickReclassify.

2. Click the Input Rasterdropdown arrow and click theraster with a value you wishto change.

3. Click the Reclass Fielddropdown arrow and click thefield you wish to use.

4. Click the new value you wishto change and type a newvalue.

5. Type the Old values entry ineach New values input boxfor all other values to keepthem the same in the OutputRaster.

6. Optionally, click Save to savethe remap table.

7. Specify a name for the OutputRaster or leave the default tocreate a temporary dataset inyour working directory.

8. Click OK.

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Grouping entries


2. Click the Input Rasterdropdown arrow and click theraster whose values you wishto group.


4. Click the New values youwish to group—click one,then hold down the Shift keyand click the next one—thenright-click on Group Entries.


6. Specify a name for theOutput Raster or leave thedefault to create a temporarydataset in your workingdirectory.

7. Click OK.

Tip

Ungrouping entriesTo ungroup entries, right-click thegroup and click Ungroup Entry.

Tip

Changing the classes ofyour old valuesClick Classify to change theclassification of your old values.

Click Unique to separate classes ofold values into unique values.

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Changing theclassification of inputranges


2. Click the Input Rasterdropdown arrow and click theraster whose values you wishto reclassify.


4. Click the Classify button.

5. Click the Method dropdownarrow and choose a classifi-cation method to use toreclassify your input data.

6. Click the Classes dropdownarrow and choose the numberof classes into which to splityour input data.

7. Click OK.

8. Modify the New values foryour output grid ifappropriate.

9. Specify a name for the OutputRaster or leave the default tocreate a temporary dataset inyour working directory.

10. Click OK in the Reclassifydialog box.

Tip

Changing input ranges tounique valuesIf your input values are split intoranges and you want them to beunique values, click Unique.

See Also

See ‘Standard classificationschemes’ in Using ArcMap.

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Setting specific values toNoData


2. Click the Input Rasterdropdown arrow and click theraster with values you wish toset to NoData.


4. Click the input boxes for theNew values you wish to turnto NoData.

5. Click Delete Entries.

6. Check Change missingvalues to NoData.


8. Specify a name for theOutput Raster or leave thedefault to create a temporarydataset in your workingdirectory.

9. Click OK.

The values you deleted willbe turned to NoData in theoutput grid.

Tip

To change a value toNoDataYou can also type “NoData” in theinput box for a new value tochange an input value to NoData.

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Converting rasters and TINs to vector data

Why convert from surfaces to vectors?

Raster and TIN surfaces may contain information that you wouldlike to use in conventional, vector-based, GIS operations. Twosuch vector-based operations are overlay and selection bylocation.

Converting rasters to features

The general steps to convert rasters to features for analysis are:

1. Convert the raster surface data to categorical data (elevation,slope, or aspect categories).

2. Convert the categories to polygons.

3. Use the polygons with other vector data and select the areasthat meet some criteria.

For example, suppose you have a raster elevation model and apolygon feature class of vegetation.

Raster elevationmodel withcontinuous valuesand raster convertedto categorical values

Polygon featureclass created fromthe raster categories

Polygon feature classof vegetation typesand selectedvegetation that fallswithin a selectedelevation classpolygon

You can also use this technique to extract linear features fromrasters. For example, you could extract stream courses or roadsfrom land cover rasters or remotely sensed images.

Converting TINs to features

Converting TINs to features involves fewer steps. You can extractslope and aspect polygons directly from TIN surfaces, or you canextract the elevation values of nodes in the TIN as a point featureclass. You can use the slope and polygon features extracted froma TIN just as you would use such features extracted from a raster.

Raster elevationmodel and vectorvegetation featureclass.

You might want to select parts of a study area that are below1,000 meters in elevation and have a particular vegetation type.In order to do the vector overlay and selection with the elevationdata, you need to convert the raster to polygons.


Convertingsurfaces to vectordataYou can convert surface data tovectors—point, line, or polygonfeatures—for use in selections oroverlay or for editing.

Rasters must be reclassified fromcontinuous data to categoricaldata—for example, from slope indegrees to slope categories orfrom elevation values to eleva-tion classes.

Converting raster data tofeatures

1. Click the 3D Analystdropdown arrow, point toConvert, and click Raster toFeatures.

2. Click the Input rasterdropdown arrow and click theraster dataset you want toconvert to a feature.

3. Click the Field dropdownarrow and click the field youwant to copy to the outputfeatures.

4. Click the Output geometrytype dropdown arrow andclick the type of feature youwant to create from yourraster data.

5. Specify a name for Outputfeatures or leave the defaultto create a temporary datasetin your working directory.

6. Click OK.

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Converting TIN data tofeatures

1. Click the 3D Analystdropdown arrow, point toConvert, and click TIN toFeatures.

2. Click the Input TIN dropdownarrow and click the TIN youwant to convert to features.

3. Click the Conversiondropdown arrow and click thetype of conversion that youwant to do.

4. Specify a name for the Outputfeature or leave the default tocreate a temporary dataset inyour working directory.

5. Click OK.

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Creating 3DfeaturesIt is often useful to have featureswith 3D geometry. Although youcan display 2D features bydraping them over a surface, 3Dfeatures are displayed morerapidly, and you can share themwith others without having tosend along the surface data.

You can convert existing 2Dfeatures to 3D in three ways. Onemethod is to derive the heightvalues of the features from asurface. The second is to derivethe height value from an attributeof the features. The third is toderive the features’ height from aconstant value.

You can also digitize newfeatures over a surface inArcMap and interpolate thefeatures’ z-values from thesurface during digitizing.

Deriving existingfeatures’ height from asurface

1. Add the 2D features and thesurface to a map or scene.

2. Click 3D Analyst, point toConvert, and click Featuresto 3D.

3. Click the Input Featuresdropdown arrow and click thefeatures that you want toconvert to 3D.

4. Click the Raster or TINSurface button to set thesource for the features’heights.

5. Click the dropdown arrow andclick the surface that youwish to use.

6. Optionally, browse to thelocation where you want tosave the output feature classor shapefile.

7. Type the name of the output3D feature class or shapefile.

8. Click OK.Tip

Creating 3D graphicsYou use the same tools to digitize3D graphics from a surface as youuse to digitize 3D features. See‘Creating 3D graphics bydigitizing over a surface’. You cancopy and paste 3D graphics fromArcMap to ArcScene.

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Deriving existingfeatures’ height using anattribute

1. Add the 2D features to a mapor scene.

2. Click 3D Analyst, point toConvert, and click Features to3D.

3. Click the Input Featuresdropdown arrow and click thefeatures that you want toconvert to 3D.

4. Click the Input FeatureAttribute button to set thesource for the features’heights.

5. Click the attribute that youwish to use for the features’heights.

6. Optionally, browse to thelocation where you want tosave the output feature classor shapefile.

7. Type the name of the output3D feature class or shapefile.

8. Click OK.

Tip

Giving all of the featuresthe same z-valueYou can click the numeric constantbutton if you want to give all of theoutput 3D features the samez-value. 2

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Creating 3D features bydigitizing over a surface

1. Add the 3D feature class—anexisting feature class withone of the following geom-etries: pointZ, polylineZ,polygonZ—to which you wantto add features to the map.

2. Add the surface that you wantto use as the source for thefeatures’ height to the map.

3. On the Editor toolbar, clickEditor and click Start Editing.

4. If you have more than onefeature class on the map,identify the workspace of thefeature class in which you willbe creating new 3D features.Click OK.

5. Click the Interpolate Point,Interpolate Line, orInterpolate Polygon button,depending on the geometry ofthe feature class you arecreating.

6. Click on the surface andcreate the edit sketch for thefeature just as you would for a2D feature.

7. When you are finisheddigitizing, click Editor andclick Save Edits.

8. Click Editor and click StopEditing.

9. Click Yes to save your edits.

Tip

Selecting the surface tosupply z-valuesIf you have more than one surfaceon the map, use the Layerdropdown list on the 3D Analysttoolbar to select the surface thatwill be the source of your features’z-values.

Tip

3D polygon featurelimitationThe perimeters of 3D polygons arewhere the z-values are stored. Theinterior elevations are interpolatedbased on these values. Forrelatively smooth surfaces, theinteriors of 3D polygon featureswill reflect the actual surfacereasonably well. If you need toaccurately model the details of anarea, use a TIN or raster surfaceinstead of polygons.

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Creating 3D graphics bydigitizing over a surface

1. Add the surface that you wantto use as the source for thegraphics’ height to the map.

2. Click the Interpolate Point,Interpolate Line, or Interpo-late Polygon button, depend-ing on the geometry of thegraphics you are creating.

3. Click the surface at thelocation where you want tostart drawing.

If you are using the Interpo-late Point tool, a point willappear.

If you are using the Interpo-late Line or InterpolatePolygon tools, the first vertexwill appear. Click the surfacewhere you want to create thenext vertex.

4. Double-click the surface tocreate the last vertex andfinish drawing.

Tip

Selecting the surface tosupply z-valuesIf you have more than one surfaceon the map, use the Layerdropdown list on the 3D Analysttoolbar to select the surface thatwill be the source of your graphics’z-values.

Tip

3D polygon graphicslimitationThe perimeters of 3D polygons arewhere the z-values are stored. Theinterior elevations are interpolatedbased on these values. Forrelatively smooth surfaces, theinteriors of 3D graphic polygonswill reflect the actual surfacereasonably well. If you need toaccurately model the details of anarea, use a TIN or raster surfaceinstead of polygons.

Tip

Using 3D graphics inArcSceneYou can copy 3D graphics thatyou’ve created in ArcMap andpaste them into ArcScene.

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IN THIS CHAPTER

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3D visualization 7• Creating a 3D scene

• Adding layers and graphics to ascene

• Defining 3D properties for layers

• Using the 3D Effects toolbar

• Navigating through a scene usingthe Fly tool

• Setting bookmarks

• Viewing in Stereo mode

• Defining properties of a scene

• Identifying and selecting features

• Managing viewers

• View settings

• Exporting a scene

• Printing a scene

Viewing data in three dimensions gives you new perspectives. 3D viewingcan provide insights that would not be readily apparent from a planimetricmap of the same data. For example, instead of inferring the presence of avalley from the configuration of contour lines, you can actually see thevalley and perceive the difference in height between the valley floor and aridge.

ArcScene lets you build multilayered scenes and control how each layer ina scene is symbolized, positioned in 3D space, and rendered. You can alsocontrol global properties for the scene, such as the illumination. You canselect features in a scene by using their attributes or their position relativeto other features or by clicking individual features in the scene. You cannavigate around a scene or specify the coordinates of the observer andtarget for a viewer.


Creating a newsceneIf you start ArcScene with anempty scene, you will probablywant to add some data to it. Youcan add data surfaces, 2D or 3Dfeature classes, or layers thatspecify how the surface orfeature data will be rendered in3D. Once you add data to ascene, you can change how thelayers of data in the scene arerendered by modifying theirlayer properties. You can alsochange general properties ofthe scene including thebackground color, the illumina-tion of the scene, and thevertical exaggeration of thescene.

Adding data in ArcScene

1. Click the Add Data button onthe ArcScene Standardtoolbar.

2. Navigate to the surface orfeature data.

3. Click Add.

Adding data fromArcCatalog

1. Navigate to the data in theCatalog tree.

2. Click and drag it onto thescene.

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3D VISUALIZATION 183

Adding data fromArcMap

1. Right-click the layer in theArcMap table of contents andclick Copy.

2. Click the ArcScene windowto make it active, right-clickScene layers, then clickPaste Layer(s).

Tip

Why is the symbology ofmy layer different inArcScene?A layer file specifies how datashould be rendered in ArcMap,ArcCatalog, or ArcScene. The 3Dproperties that you can set for alayer—those found on the BaseHeights, Extrusion, and Renderingtabs—do not apply in ArcMap.Similarly, some symbology that youcan set in ArcMap—multilayersymbols, dashed lines—will notshow up in ArcScene. Features inArcScene can be symbolized withsimple symbols and using gradu-ated symbols or colors.

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Copying and pasting 3Dgraphics from ArcMap

1. Click the Select Graphicsbutton on the ArcMap Toolstoolbar.

2. Click the graphic.

3. Right-click the graphic andclick Copy.

4. In ArcScene, click Edit andclick Paste.

Adding 3Dgraphics to asceneOnce you’ve added data to ascene, you may find that youalso want to add a 3D graphic.For example, you might havecreated a single contour line; aline of sight; a steepest path; orsimple 3D point, line, orpolygon graphics with one ofthe 3D Analyst tools in Arc-Map. You can copy and pastethese 3D graphics from ArcMapinto ArcScene.

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Feature data and 3D

You may want to visualize feature data, as well as surfaces, in aperspective view.

Feature data differs from surface data in representing discreteobjects, rather than continuous phenomena. Features typicallyhave a shape (geometry) and attributes.

Some typical feature geometries are point, line, or polygon. Pointfeatures might represent mountain peaks, telephone poles, or welllocations. Lines might represent roads, streams, or ridgelines.Polygons might represent buildings, lakes, or administrativeareas. The attributes of features can store values that refer to theelevation or height of the features. Some GIS features storeelevation values with the feature geometry itself; for example,PointZ features are stored as a set of x,y,z coordinates. You canuse z-values in the geometry or attributes of features to displaythe features in a 3D scene.

U.S. cities, height extruded based on population in 1990Building footprints extruded by building height

Sometimes features lack elevation or height values. You can stillview these features in a 3D scene by draping or extruding them. Ifyou have a surface model for the area, you can use the values inthe model as z-values for the features. This is called draping thefeatures. You can also use this technique to visualize image datain 3D. If you want to show building features in 3D, you canextrude them using an attribute such as building height ornumber of stories. You can also extrude features based on anarbitrary value.

Sometimes you’ll want to view 2D features in a scene withz-values taken from some attribute other than a height value. Forexample, you might create a scene that shows city pointsextruded into columns based on their population.


Defining thez-values for alayerWhen you add a layer to ascene, it may not initially berendered in 3D. TINs andfeatures with 3D geometries—for example, pointZ, polylineZ,polygonZ, and multipatchshapes—are automaticallydrawn in 3D. Rasters (grids andimages) and 2D features aredrawn as though they wereresting on a flat surface. Inorder to view rasters and 2Dfeatures in 3D, you need todefine their z-values.

3D Analyst adds three tabs tothe Properties dialog box thatallow you to control how afeature layer is displayed in 3D.There are three ways to render2D features in 3D. These aresetting base heights using anattribute, setting base heightsby draping features on asurface, and extruding features.There are some variations onthese methods, and you cancombine them—for example,you can set base heights from asurface, then extrude thefeatures above or below thesurface.

You can set the base heights ofraster layers using a surface ora constant value.

Examining the baseheights of a layer

1. Right-click the layer and clickProperties in ArcScene orArcCatalog.


This layer does not havebase heights.

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Setting the base heightfrom an attribute

1. Right-click the layer and clickProperties.


3. Click the option to Use aconstant value or expressionto set heights for features inlayer.

4. Click the Calculate button.

5. Double-click the field that willprovide the z-value for thefeatures.

6. Click OK. u

Tip

Using built-in z-values of alayerSome feature data includesz-values in the feature geometry. Ifyou examine the attribute tables ofthese feature layers, you will seethat the shape field says PointZ,PolylineZ, or PolygonZ. Featureswith 3D geometry are automati-cally displayed in 3D in a sceneusing the z-values from the featuregeometry. You can set the baseheight of these features using anattribute or a surface if you do notwish to use the built-in z-values. Ifyou then want to switch back tousing the z-values, click the Layerfeatures have Z values. Use themfor heights. option.

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7. Click OK in the Propertiesdialog box.

The 2D features are nowdrawn in 3D, using theattribute that you selected asthe z-value.

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Perspective view of contours, base heights set using the contours’elevation attribute


Setting a feature layer’sbase heights using asurface



3. Click the option to Obtainheights for layer from surface.

4. Click the dropdown list andclick the surface that youwant to use for the baseheights.

5. Click OK.

The layer is now drawn in3D, using the surface thatyou selected to provide thez-values.

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Extruding the features ina layer



3. Check the check box toextrude the features in thelayer.

4. Click the Calculate button tocalculate an extrusionexpression. u

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5. Double-click an attribute youwant to include in theexpression.

6. Optionally, build a calculationthat includes the attribute.

7. Click OK.

8. Optionally, click the drop-down arrow to specify howthe extrusion should beapplied.

9. Click OK. u

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The features are extrudedinto 3D.


Raster data and 3D

Rasters sometimes contain continuous surface data—when theydo, rendering them in 3D is a simple matter of setting the rasterlayer’s base height to itself. You can improve the appearance ofthe surface by setting the symbology, shading, base resolution,and—if the surface’s z-units are not equal to its x,y units—z-unitconversion factor.

Terrain surface draped over a surface—itself

Aerial photo draped over a surface

Categorical raster draped over a surface

USGS quad map draped over a surface

Rasters often contain other kinds of discontinuous (nonsurface)data about an area—for example, thematic land use data, remotelysensed image data, scanned maps, or the results of surfaceanalyses—that can be mapped directly to a surface. You candisplay a nonsurface raster in 3D by draping it over a surfacemodel of the area. This can be a very effective way of visualizingthe relationship between the raster and the surface.


Defining the 3Dproperties of araster layerWhen you add a raster layer toa scene, it is initially drawn asthough it were resting on a flatsurface. In order to view rastersin 3D, you need to define theirz-values. 3D Analyst adds twotabs to the Properties dialogbox that allow you to controlhow a raster layer is displayedin 3D. Rasters can be renderedin 3D by interpolating heightsfor the raster using values inthe raster itself, by using valuesin another (raster or TIN)surface, or by giving the rastera constant base height.

Tip

What is the RasterResolution?When you drape a raster over araster surface, the base surface isresampled to 256 rows by256 columns to improve perfor-mance. You can change theresolution of the base surface byclicking Raster Resolution andsetting either the cell size or thenumber of rows and columns. Asmaller number of rows andcolumns improves performance butreduces the resemblance of thebase surface to the original.

Setting a raster layer’sbase heights using asurface



3. Click the option to Obtainheights for layer from surface.

4. Click the dropdown arrowand click the surface that youwant to use for the baseheights.

5. Optionally, click RasterResolution to set the resolu-tion of the base surface.

6. Click OK. u

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The raster layer is nowdrawn in 3D, using thesurface that you selected toprovide the z-values.


Convertingz-units to x,yunitsGeographic data is typicallycollected and represented in acoordinate system that has thesame x and y units. However,when heights, depths, orelevations are recorded forfeatures or surfaces, the z-unitsare not always the same as thex,y units of the coordinatesystem. For example, a set ofwell features might be stored inUniversal Transverse Mercator(UTM) meters but have a welldepth attribute in feet. In orderto represent the wells correctlyin 3D, the z-values must beconverted to meters. Otherwise,when you extrude the wells in ascene, they will appear to bethree times as deep as theyreally are.

Converting units



3. Click the Z Unit Conversiondropdown arrow and clickone of the predefined typesof conversion.

If you need to apply a customconversion, click custom.

4. Optionally, if you’re using acustom conversion, type theconversion factor.

5. Click OK.

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Offsetting theheights in a layerYou can add a constant amountor calculated value to the baseheight of a layer to raise—orlower—it relative to otherlayers in a scene. This can beuseful when creating 3Dvisualizations to ensure that alayer is visible above a surface,allow comparison of the shapesof two surfaces, or provide z-values for power lines or pipesthat have a given depth aboveor below a known surface.

The offset can be relative tobase heights determined usinga constant or expression, asurface, or z-values embeddedin feature geometries.



3. Type a constant value for theoffset.

4. Optionally, click the Calculatebutton to create an expres-sion to define the offset.

5. Click OK.

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Controlling whena layer isrenderedScenes can contain manylayers, and rendering somelayers can be quite demandingon your computer’s resources.If you find that rendering aparticular large or complex datalayer causes navigation in ascene to be sluggish, you canset it to display only whennavigation has ceased. Allow-ing a simpler layer to berendered during navigation canprovide landmarks to allow youto navigate accurately while thecomplex layer is not visible.

Rendering a layer onlywhen navigation isstopped



3. Click the option to Renderlayer only while navigationhas stopped.

4. Click OK.

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Rendering a layer onlyduring navigation



3. Click the option to Renderlayer only while navigating.

4. Click OK.

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Using the 3DEffects toolbarUsing the 3D Effects toolbar,you can access a layer’s displayproperties without opening itsproperties dialog box. Use the3D Effects toolbar to adjust alayer’s transparency, change itsface culling, toggle its lighting,set its shading mode, or rank itsdepth priority.

Turning on the 3D Effectstoolbar

1. Right-click in the blank areanear the menus and toolbarsand click 3D Effects.

The 3D Effects toolbarappears.

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Using the 3D Effectstoolbar to set a layer’stransparency

1. Click the Layer dropdownarrow and choose the layeryou want to change.

2. Click the Adjust Transpar-ency button and move theslider to a value.

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Using the 3D Effectstoolbar to adjust layerface culling


2. Click the Layer Face Cullingbutton and click the optionyou want to use.

The default setting is to viewboth sides.

3. Optionally, click a differentviewing option.

View only one side of a layerto make the data inside itvisible.

Using faceculling to controlthe way layersare drawnFace culling is a property that isonly accessible from the 3DEffects toolbar. Use culling toturn off the display of front orback faces of an areal feature orgraphic. For example, if youhave data that is surrounded bya multipatch shapefile used fora backdrop, use culling to turnoff the display of one of thebackdrop faces so that you canalways see your data, evenwhen zoomed outside of thebackdrop extent.

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Using the 3D Effectstoolbar to change alayer’s drawing priority


2. Click on the Change DepthPriority button and move theslider to a value.

Changing alayer’s drawingpriorityIf two layers occupy the samelocation in 3D space, a stitchingeffect may be seen when thelayers are drawn in a scene.This is because they arecompeting with each other to bedisplayed. To reduce the effect,assign a priority to the layersso that you control the order inwhich they are drawn. Forexample, if your scene containsa feature layer draped on asurface layer, and you notice aconflict between the layers, youcan lower the priority of thesurface so that the features arealways drawn first. Priority canonly be changed for area-basedfeatures, such as polygons,rasters, and TINs.

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Viewing a scene from different angles

By default, ArcScene has a single window for viewing yourscene, but you can create multiple viewer windows for a scene.Having additional viewers lets you focus on specific areas fromthe best angles while still seeing the whole.

You can navigate independently within each viewer window—thenavigation tools control the view within the window they’re usedin. You can even make the scene rotate in one viewer andnavigate in another.


Managing sceneviewersMultiple viewers let you see ascene from different angles atthe same time. Each viewer canbe independently navigated.You can maximize viewers to fillthe screen, minimize viewers toget them out of the way, restoreviewers to their previous size,or close them altogether.

The properties of a scene applyto all of the viewers.

Adding a viewer

1. Click Window and click AddViewer.

Closing a viewer

1. Right-click the title bar of theviewer and click Close.

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Managing viewers

1. Click Window and clickViewer Manager.

2. Click a viewer in the Selectviewer list.

3. Click Hide to hide theselected viewer.

4. Click Show to show theselected viewer.

5. If you have minimized aviewer, you can click Restoreto restore it to its previoussize.

6. Click Close Viewer(s) topermanently close theviewer.

7. Click OK to close the ViewerManager.

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Changing theviewer settingsYou can also change the wayyou see a scene in each viewerin several ways.

You can switch a viewer from aperspective view to an ortho-graphic view with no perspec-tive distortion of scale. Thislets you examine the data in theview as though it were on a 2Dmap.

You can change the roll angleand pitch of a viewer.

You can also change theposition of a viewer and itstarget point by typing x,y,zcoordinates.

You can continue to navigate ina viewer as you view the viewersettings—the position, pitch,and roll values are updated inthe View Settings dialog boxwhen you stop navigating.

Setting a viewer to 2D

1. Click View and click ViewSettings.

2. If you have more than oneviewer for the scene, click thedropdown arrow and selectthe viewer that you want tochange.

3. Click Orthographic (2D view).

You see an orthographicview of the scene with noperspective distortion ofscale.

4. Click Cancel to close theView Settings dialog box.

Tip

Extruded points limitationExtruded points are not visible inorthographic view.

If you need to see extruded pointdata in an orthographic view, copyand paste the layer in the scene andturn off extrusion for the copy.

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Changing the roll andpitch of a viewer



3. Click the roll slider and dragit to change the roll.

The artificial horizon and theviewer roll to the new rollangle.

4. Click the pitch slider anddrag it to change the pitch.

The artificial horizon and theviewer pitch to the new pitchangle.


Tip

Why can’t I set the roll andpitch?Roll and pitch are only applicablein perspective viewing. If you havethe viewer set to Orthographic, thepitch and roll controls aredisabled.

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Specifying thecoordinates of theobserver or target



3. Type the x,y,z coordinates forthe Observer.

4. Type the x,y,z coordinates forthe Target.

5. Click Apply to set the viewerto the new observer andtarget coordinates.


Tip

Finding a target’scoordinatesWith the View Settings dialog boxopen, click the Center on Targettool and click a location in thescene. The viewer centers on thetarget, and you can see its x,y,zcoordinates.

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Navigatingthrough a sceneusing the Fly toolUse the Fly tool to investigateyour scene by flying through it.You can fly in any direction andmove forward or backward atdifferent speeds.

Using the Fly tool tonavigate in a scene

1. Click the Fly button.

The cursor changes toindicate fly mode is active.

2. Click once in the center of thescene.

The tool enters the sus-pended state. You can pointthe mouse to look in alldirections, but there is notranslational movement.

3. Click the mouse to moveforward.

Right-click to move in reverse.Successive clicks in eitherdirection increase the speed.Speed is indicated in thestatus window.

4. Click the opposite button toslow down incrementally andthen stop.

Press Esc to immediately stopmovement in either direction.

Tip

Fine-tuning the fly speedIn between mouse clicks, pressarrow up or down to increase ordecrease speed, respectively.

Tip

Looking up or down whileflyingPress Shift while flying to maintaina constant elevation. You can thenpoint the mouse up or down to lookin those directions withoutchanging the direction of travel.

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SettingbookmarksA 3D bookmark identifies aparticular camera perspectivethat you want to save and referto later. For example, you mightwant to create a 3D bookmarkthat identifies a certain view ofa study area. That way, as younavigate through your scene,you can easily return to thestudy area view by accessingthe bookmark. You can also use3D bookmarks to highlightareas in your scene you wantothers to see.

The list of bookmarks applies toall viewers in a scene. If youcreate a bookmark in a viewer, itwill be added to a central listand can be applied to anyviewer.

Creating a perspectivebookmark

1. Navigate to the perspectivefor which you want to createa bookmark.

2. Click the View menu, point toBookmarks, and click Create.

3. Type a name for the book-mark.

4. Click OK.

Using a perspectivebookmark

1. Click the View menu, point toBookmarks, and click thename of the bookmark youwant to use.

The bookmarked viewappears.

Tip

Using bookmarks insecondary viewersTo create or use a bookmark in asecondary viewer, right-click on itstitle bar and click Bookmarks.

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Viewing in StereomodeStereo viewing provides addeddepth and realism to your 3Dscenes. You can view yourscenes in stereo by using redand blue stereo viewingglasses, using a polarizedstereo shutter for your monitorin combination with specializedeyeglasses, or projecting theimages in a scene and viewingthe images with specializedeyeglasses.

Red and Blue Anaglyph modedisplays the scene in overlap-ping red and blue views. Whenyou view these scenes with redand blue stereo viewingglasses, you’ll benefit from anenhanced 3D effect.

You can also use a polarizingshutter glass for your computermonitor and accessory glassesthat you wear to view in stereowith true color.

Finally, if you’d like to displayyour scenes in stereo projectedto an audience, you can useFree mode stereo viewing tosend left and right images toindependent projectors andthen view the images withspecialized glasses. u

Viewing the display instereo using red and blueanaglyphs


2. In the Applies to dropdownmenu, select the viewer youwant to view in stereo.

3. Click Stereo View.

4. Click the Method dropdownmenu and click Red/Blue.

The view mode changes sothat a red anaglyph of thescene is drawn superim-posed and to the right of ablue anaglyph. Use red andblue stereo viewing glassesto add more of a 3D feel toyour scene.

5. Optionally, move the EyeSeparation slider to the rightto increase the distancebetween the anaglyphs, or tothe left to decrease theseparation.

You may need to adjust thisto accommodate the distancebetween your eyes or thedistance between you andthe computer screen. u

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6. Optionally, move the Parallaxslider to the right to increasethe movements of sceneobjects relative to theobserver, or left to decreasethe relative movements.

Increasing the parallaxaccentuates the movementsof objects in the scene asyou look at them.

7. Optionally, click Reverse leftand right views to switch thered and blue sides of theview.

8. Click Cancel.

Shutter Glass mode requires aquad-buffer graphics card toaccommodate the shutter. Freemode requires a quad-buffergraphics card with dual outputin order to project images instereo.

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Viewing the display instereo using a shutterglass

You will need to have apolarized shutter glass onyour monitor and a pair ofaccompanying eyeglasses.




4. Click the Method dropdownmenu and click Shutter glass.

The view mode changes sothat a polarized version ofthe scene is sent through theshutter. Use accessory stereoviewing glasses to view thescene in stereo.

5. Optionally, move the EyeSeparation slider to the rightto increase the imageseparation, or to the left todecrease the separation.


7. Optionally, click Reverse leftand right views.

8. Click Cancel.

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Projecting the display instereo using free viewing

You will need a graphics cardthat supports output to twomonitors.




4. Click the Method dropdownmenu and click Free.

The view mode changes sothat left and right views of thescene are placed side byside. You can send each viewto independent projectors fordisplay on a screen and thenview the image for a stereoeffect.

5. Optionally, move the EyeSeparation slider to the rightto increase the left and rightimage separation, or to theleft to decrease the separa-tion.


7. Optionally, click Reverse leftand right views.

8. Click Cancel.

Tip

Free viewing exampleFor an example of how stereoviewing is accomplished on aprojection screen, visitwww.geowall.org.

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Setting the properties of a scene

In ArcScene, you can set certain properties—for example, verticalexaggeration, animated rotation, background color, extent, andillumination properties—that apply to the scene and all the layerswithin it. You can also add comments about the scene and set itscoordinate system. If your scene has multiple viewers, theseproperties also apply to all of the viewers.

Vertical exaggeration emphasizes variation in a surface.

The background color can make visualizations more realistic.

Illuminating a scene from different angles emphasizes differentparts of a surface.

The tabs of the Scene Properties dialog box let you set thevarious global scene properties.


Changing theverticalexaggerationVertical exaggeration can beused to emphasize subtlechanges in a surface. This canbe useful in creating visualiza-tions of terrain where thehorizontal extent of the surfaceis significantly greater than theamount of vertical change in thesurface. A fractional verticalexaggeration can be used toflatten surfaces or features thathave extreme vertical variation.

The vertical exaggeration isapplied to all layers in a scene.You can exaggerate a singlelayer by changing its z-unitconversion factor.

1. Right-click Scene layers andclick Scene Properties.


3. Click the Vertical Exaggera-tion dropdown arrow andclick a vertical exaggerationfactor.

4. Optionally, click CalculateFrom Extent to automaticallycalculate an exaggerationfactor based on the extentand z-variation in the scene.

5. Click OK.

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Using animatedrotationRotating a scene is a good wayto get an overview of itscontents. You can make a scenespin around the current centerwhen animated rotation isenabled.

You can adjust the rotationspeed and the observationangle and zoom in and out whilethe scene rotates.

Enabling animatedrotation



3. Check the check box toenable animated rotation.

4. Click OK.

The navigate cursor has acircle around it whenanimated rotation is enabled.

Tip

Toggling animated rotationusing shortcut keysWhile in navigation mode, you cantoggle on and off animated rotationin a specific viewer by pressingCtrl and Shift while clicking in thatviewer.

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Starting animatedrotation

1. Click the Navigate buttonafter enabling animatedrotation.

The navigate cursor has acircle around it whenanimated rotation is enabled.

2. Click the scene, hold themouse button down, drag tothe left or right, and releasethe mouse button while thescene is in motion.

The speed at which thescene rotates is proportionalto the speed at which themouse is moving when yourelease the button.

Click the scene to stop therotation.

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Changing the rotationspeed

1. While the scene is rotating,press the Page Up key toincrease the rotation speedand press the Page Downkey to decrease the rotationspeed.

Tip

Starting animated rotationwith complex dataTo start complex data rotating,press Shift while dragging rapidlyin the direction you want the sceneto rotate.

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Changing thebackground colorThe background color forscenes is white by default. Youcan change the backgroundcolor to suit your visualizationneeds. Various shades of bluecan make the backgroundappear to be a blue sky, while ablack background can simulatenight.

You can quickly set thebackgound to one of the presetcolors or mix your own color.You can also make the currentbackground color the defaultfor all new scenes.

Setting the backgroundcolor



3. Click the Background colordropdown arrow.

4. Click a color.

5. Optionally, click More Colorsto mix your own backgroundcolor.

6. Click OK.

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Setting the defaultbackground color forfuture scenes



3. Check the check box to usethe current color as thebackground in all newscenes.

4. Click OK.

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Changing thesceneilluminationYou can set the azimuth andaltitude of the light source, aswell as the amount of contrast,used in rendering the illumina-tion of the scene. The illumina-tion properties for a sceneapply to all of the areal features,including extruded polygon andline features, in a scene.

You can control whetherindividual layers are shaded byturning shading on or off on theRendering tab of the layer’sProperties dialog box.

Setting the illuminationazimuth


2. Click the Illumination tab.

3. Type an Azimuth for thescene light source.

4. Click OK.

Tip

Changing illuminationproperties quicklyYou can click on the sun graphic inthe Azimuth and Altitude controlsand drag it where you want it,instead of typing values into the textboxes. The illumination previewand the values in the text boxes willchange to reflect the new position.

Tip

What is the azimuth?The azimuth is the compassdirection from which the lightsource shines on the scene.

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Setting the illuminationaltitude



3. Type an altitude for the scenelight source.

4. Click OK.

Tip

What is the altitude?The altitude is the height, measuredin degrees above the horizon, fromwhich the light source shines on thescene.


Setting the illuminationcontrast



3. Type a contrast value.

4. Click OK.

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What is the contrast?The contrast controls the amount ofshading applied to a surface.

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Changing thescene extentReducing the extent of a scenecan be a useful way to removeextraneous information andincrease rendering performance.

By default, the extent of a sceneis the combined extent of all ofthe layers in the scene. You canchange the extent of a scene tobe the same as the extent of oneof the layers or set it usingspecific minimum and maximumx- and y-coordinates.

Data that falls outside of theextent of the scene is notdisplayed.

Setting the extent to alayer



3. Click Layer(s), click theLayer(s) dropdown arrow,then click the layer you wantto define the scene extent.

4. Click OK.

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Setting the extent usingcoordinates



3. Click Custom.

4. Type minimum and maximumx and y values to define theextent of the scene.

5. Click OK.

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Changing thescene coordinatesystemIf all the data you want todisplay in a scene is stored inthe same coordinate system—for example, you’re using yourorganization’s database—youcan just add it to a scene andnot consider whether the layerswill overlay properly; they will.If, however, you’ve collecteddata from a variety of sources,you’ll need to know whatcoordinate system each datasetuses to ensure ArcScene candisplay them together.

When you add a layer to anempty scene, that layer sets thecoordinate system for thescene; you can change it later ifnecessary. As you add subse-quent layers, they are automati-cally transformed to the scene’scoordinate system as long asthere’s enough informationassociated with the layer’s datasource to determine its currentcoordinate system. If there isn’tenough information, ArcScenewill be unable to align the dataand display it correctly. In thiscase, you’ll have to supply thenecessary coordinate systeminformation yourself.

ArcScene expects coordinatesystem information to be storedwith the data source. u

Finding out whatcoordinate system yourdata is currentlydisplayed in


2. Click the Coordinate Systemtab.

The details of the currentcoordinate system aredisplayed in the dialog box.

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For a layer in a geodatabase,this information is part of thelayer’s metadata. For coverages,shapefiles, TINs, and rasters,it’s stored on disk in a separatefile named after the data sourcebut with a .prj file extension (forexample, streets.prj). These filesare optional files; thus you maystill need to define the coordi-nate system for one of thesedata sources. You can create a.prj file with ArcCatalog.

If no coordinate systeminformation is associated with adata source, ArcScene willexamine the coordinate valuesto see if they fall within therange: -180 to 180 degrees for x-values and -90 to 90 degrees fory-values. If they do, ArcSceneassumes that these are geo-graphic coordinates of latitudeand longitude. If the values arenot in this range, ArcScenesimply treats the values asplanar x,y coordinates.

See Also

For more information on coordi-nate systems, see UnderstandingMap Projections.

Displaying data with apredefined coordinatesystem


2. Click the Coordinate Systemtab.

3. Double-click Predefined.

4. Navigate through the foldersuntil you find the coordinatesystem you want and click it.

5. Click OK.

All layers in the scene willnow be displayed with thatcoordinate system.

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Changing the coordinatesystem of a sceneChanging the coordinate system ofa scene does not alter the coordi-nate system of the source datacontained in it.


Selectingfeatures in asceneThere are several ways to selectfeatures in a scene. The mostdirect way to select features isto click them in the scene withthe Select Features tool or toclick them in an attribute table.When a feature is selected it ishighlighted.

You can also select features bytheir attributes as well as bytheir location with respect toother features. For example, youcould select all of the polygonsthat you’ve classified as havingmoderately steep slope, thenselect all of the buildings thatare within these polygons.

Selecting featuresinteractively by clickingin a scene

1. Click the Select Featurestool.

2. Click the feature you want toselect.

The selected feature ishighlighted.

Changing the interactiveselection method

1. Click Selection, point toInteractive Selection Method,and click the selectionmethod you want to use.

Tip

Learning more aboutselectionFor more information aboutselecting features, see UsingArcMap.

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Selecting featuresinteractively by clickingon a table

1. Right-click the feature layerand click Open AttributeTable.

2. Click the row belonging tothe feature you want toselect.

The selected feature ishighlighted.

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Selecting features bytheir attributes

1. Click Selection and clickSelect By Attributes.

2. Click the Layer dropdownarrow and click the layer fromwhich you want to selectfeatures.

3. Click the dropdown arrowand click the selectionprocedure that you want touse.

The default selectionprocedure is to create a newselection, but you can alsoadd to, remove from, orselect from the currentselection.

4. Double-click the attributefield that you want to selectfrom.

5. Click an operator, for ex-ample, the equals sign.

6. Double-click a value.

7. Optionally, click Verify tocheck your selectionexpression.

8. Click Apply.

9. Click Close.

The features are selected.

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Selecting features bytheir location

1. Click Selection and clickSelect By Location.

2. Click the dropdown arrowand click a selection method.

3. Check the layers whosefeatures you would like toselect.

4. Click the dropdown arrowand click a selection method.

5. Click the dropdown arrowand click the layer you wantto use to search for thefeatures.

6. Optionally, check to use onlythe selected features.

7. Optionally, check Apply abuffer to the features in<layer> and set the distancewithin which to search forfeatures.

8. Click Apply.

9. Click Close.

The features are selected.

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Exporting asceneYou can export a 2D image of ascene to a graphics file, or youcan export a 3D Virtual RealityModeling Language (VRML)model. Images of scenes can besaved in several common fileformats and placed in otherdocuments—for example, inmaps or reports.

Exporting a 2D graphic ofa scene

1. Click File, point to ExportScene, and click 2D.

2. Navigate to the locationwhere you want to save theimage of the scene.

3. Click the dropdown arrow tochoose the graphics fileformat to export.

4. Type the width of the ex-ported graphic in pixels.

5. Type a name for the graphic.

6. Click Export.

The scene is exported to a2D image.

Tip

Taking a snapshot of asceneSometimes you just need a quicksnapshot of a scene. Click Edit andclick Copy scene to clipboard. Youcan then paste the snapshot onto amap or other document.

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Exporting a 3D VRMLmodel of a scene

1. Click File, point to ExportScene, and click 3D.

2. Navigate to the locationwhere you want to save theVRML model.

3. Type a name for the VRMLfile.

4. Click Export.

The scene is exported to aVRML file.

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Printing a sceneWhen you want a hardcopy ofa scene, you can print one. Youcan quickly print to your defaultprinter, or you can change thepage setup to select anotherprinter and specify the detailsof how you want the scene toprint.

1. Click the Print button.

2. Optionally, click Setup.

3. Optionally, click the drop-down arrow to select aprinter.

4. Optionally, click the drop-down arrow to select a pagesize.

5. Optionally, click Portrait orLandscape to select thepage orientation.

6. Optionally, click the drop-down arrow to select aprinter engine.

7. Optionally, click OK.

8. Click OK on the Print dialogbox.

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Animation 8• 3D animation

• Creating animations

• Capturing perspective views

• Recording and playing backanimation tracks

• Creating keyframes

• Making group animations

• Making animations from paths

• Using the Animation Manager

• Timing properties in theAnimation Manager

• Saving an animation

• Sharing animations: Loading anArcScene or ArcGlobe Animationfile

Animations make your 3D documents come alive by storing actions so theycan be replayed as you choose. They can help you visualize changes inperspective, changes in the document’s properties, geographical movements,and temporal changes.

You might create an animation that helps you visualize how moving satellitesreact with one another during their orbit. In addition, you may model theearth’s rotation and change in lighting at the same time.

You create animations using the Animation toolbar. You can make animationsthat manipulate data, perspective, and scenes or globes.

An animation consists of one or more tracks. Tracks control dynamicchanges of the properties of an object, such as a document’s backgroundcolor, a layer’s visibility, or a camera’s location. Tracks are made up of a setof keyframes. A keyframe is a snapshot of a particular object’s properties ata certain time. The object can be a scene or globe, a layer, or a camera. Forexample, you can create a track with the scene or globe object that animatesscene or globe property keyframes to show the background color changingfrom white to black.

Animation tracks are stored in the current document. They can also besaved into a separate file that may be shared by numerous scenedocuments. An animation may also be exported as an Audio VideoInterleave (.avi) or QuickTime (.mov) file that can be played by third partyvideo players.

Animations provide a new and actuated aspect to your 3D documents. Useanimations to automate the processes you would undertake to demonstratepoints that can only be made through visual dynamics.


3D animation

ArcScene and ArcGlobe let you create, save, and shareanimations. You can create animations in different ways,composing the animation of multiple tracks that animate the sceneor globe properties, a layer, or the camera. An animation may besaved in a document, saved as an independent ArcSceneAnimation (.asa) or ArcGlobe Animation (.aga) file, or exported toa .avi or .mov file. You can share animations by exchangingdocuments, interchanging .asa and .aga files, or distributing .aviand .mov files.

The camera and the target

You view your scene or globe through viewer cameras. Acamera’s location is defined by the observer property. The centerof your view is called the target. Imagine what you see is what thecamera sees. As you navigate through a 3D view, you are actuallymoving the observer in conjunction with the target. If you set anew target on the data, that point on the data is shifted to thecenter of your view. There is only one camera, observer, andtarget set in any viewer. Familiarizing yourself with the camera,observer, and target will help you gain a better understanding ofanimation.

Introducing the Animation toolbar

The Animation toolbar has all the tools you’ll need to work withanimations in ArcScene and ArcGlobe. Using these tools, you canrecord navigation, capture perspective views, save and exporttracks, create video files, make group animations, create tracksfrom paths, and manage and preview your animations.

Creating an animation

You create an animation by composing the tracks it will contain.You can make tracks by creating a set of keyframes, recordingactions, alternating the visibility of groups of layers, andimporting paths that constrain movement. Use the AnimationManager to edit tracks and keyframes and organize how thetracks in an animation interact with each other.

Saving an animation

There are three ways to save an animation. A 3D document willautomatically store an animation that is present when thedocument is saved. In addition, you can save the animationtracks to a .asa or .aga file. Finally, you can create a standalonevideo by exporting the animation as a .avi or .mov file.

ANIMATION 239

Sharing animations

You can share animations by loading a 3D document thatcontains an animation, loading .asa or .aga files into ArcScene orArcGlobe, and viewing .avi or .mov files that were created fromanimations. Use a shared document with an animation todemonstrate a particular point to colleagues. Independent .asaand .aga files can be used as templates for others to build on oras generic animations that can be utilized with various data. Sharea .avi or .mov file for picture-perfect, highly detailed animationsthat can be played in real time to a wide and varied audiencewhen you need to quickly demonstrate a problem that can onlybe shown dynamically.


Turning on the Animationtoolbar

1. Click View, point to Toolbars,and click Animation.

The Animation toolbarappears as an undockedtoolbar.

CreatinganimationsThere are several ways to createanimations. The simplestmethod, capturing perspectiveviews, is quick and can be donewith any data. A more complexmethod of creating animationsis to create animations frompaths defined by selected linefeatures or graphics. Thismethod requires specific typesof data in the scene but canprovide a more visuallyappealing animation.

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CapturingperspectiveviewsUse the Capture View commandto save perspective views askeyframes in a camera track.The resulting track will be aninterpolation between thekeyframes, making a smoothanimation. For example, you cancreate a track that rotates yourscene or globe, zooming in andout to points of interest alongthe way.

Capturing views to makean animation

1. Navigate to the perspectiveyou want to capture.

2. Click the Capture Viewbutton.

3. Repeat to capture moreviews as keyframes in acamera track.

Clearing an animation

1. Click Animation and clickClear Animation.

All animation tracks areremoved from the scene.

See Also

To learn how to play back ananimation track, see ‘Recordingand playing back animation tracks’in this chapter.

Tip

Is there a shortcut tocapturing views?To capture a view to an animation,press Ctrl+A instead of clicking theCapture View button.

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Playing back ananimation

1. Click the Open AnimationControls button.

2. Press the Play button.

The animation is playedback.

Recording navigation tocreate an animation

1. Click the Open AnimationControls button.

2. Click the Record button.

3. Navigate in the scene usingany navigation tool.

4. Click the Stop button.

A camera track is created,storing the navigationsequence.

Recording andplaying backanimation tracksSimple recording and playbackare achieved using controls thatresemble a VCR. Press theRecord button to record yournavigation and press the Playbutton to play it back.

Tip

Controlling playback andrecording optionsClick Options on the AnimationControls toolbar to accessanimation duration, segments ofanimation to play back, loopingmode, and overwriting options.

Tip

Recording Fly or Walk toolnavigationYou can make a flyby or walk-through animation by recording asyou fly or walk through your sceneor globe with the Fly and Walktools.

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CreatingkeyframesKeyframes are the mostfundamental elements of ananimation. A series of keyframesis assembled into a track. Createa keyframe to make a snapshotof an object’s properties. Usekeyframes to make snapshots ofscene or globe properties,camera properties, or layerproperties, such as a 3D view’sbackground color, a layer’stransparency, or a camera’slocation.

Creating a keyframe ofscene properties


2. Set the scene property orproperties you want tocapture.

3. Turn on the Animationtoolbar, click Animation, andclick Create Keyframe.

4. Click the Type dropdownarrow and choose Scene.

5. Click New to create a newscene track.

6. Click OK.

7. Click Create.

8. Click Close.

You can repeatedly change aproperty and create a newkeyframe without closing theCreate Animation Keyframedialog box. Note that youneed at least two keyframesto create a track that willshow change.

Tip

How can I edit keyframeproperties?You can edit the properties of akeyframe by using the AnimationManager.

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Creating a keyframe ofcamera properties

1. Navigate to the cameraposition you want to capture.

2. Click Animation and clickCreate Keyframe.

3. Click the Type dropdownarrow and choose Camera.

4. Click New.

5. Click OK.

6. Click Create.

7. Click Close.

You can change a cameraproperty by navigating to anew position, then create anew keyframe repeatedlywithout closing the CreateAnimation Keyframe dialogbox. Note that you need atleast two keyframes to createa track that will show change.

Tip

How else can I create akeyframe?You can create keyframes from theKeyframes page of the AnimationManager dialog box. Click Createto invoke the Create AnimationKeyframe dialog box. For moreinformation, see ‘Using theAnimation Manager’.

Tip

Using bookmarks askeyframesIf your document has bookmarks,you can import them to ananimation as keyframes bychecking Import from bookmarksand choosing a bookmark in thedropdown list.

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ANIMATION 245

Creating a keyframe oflayer properties

1. Change the layer propertythat you want to capture.

For example, turn on the 3DEffects toolbar and set atransparency for a layer.

2. Click Animation and clickCreate Keyframe.

3. Click the Type dropdownarrow and choose Layer.

4. Click New.

5. Click OK.

6. Click Create.

7. Click Close.

You can repeatedly change aproperty and create a newkeyframe without closing theCreate Animation Keyframedialog box. Note that youneed at least two keyframesto create a track that willshow change.

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Making groupanimationsYou can create an animationfrom an existing group layer orindividual layers within a scene.For example, you might have agroup layer in which individuallayers represent snapshots intime. If these layers are orderedsequentially in the TOC, youcan create tracks that succes-sively turn visibility on and offfor each layer within the group.The animation will depend onthe ordering in the TOC, soarrange layers in the order thatyou want them played. Thetracks will show how the datachanges through time.

Making a groupanimation

1. Click the Add Data button toadd the layers or group layerthat you want to animate.

2. Click Animation and clickCreate Group Animation.

3. Optionally, choose a Basename for tracks.

You are provided with adefault name for the tracks,but you can change it tosomething more meaningful.

4. Optionally, set the beginningand ending times.

Setting these times allowsyou to determine when thegroup animation will playrelative to other tracks thatmay exist.

5. Select a group layer. You canclick a group layer or all thelayers in your scene.

6. Optionally, changeTransitions.

These options will help youdetermine how layers in ananimation change from oneto another.

7. Optionally, uncheck Over-write existing tracks withsame name to add additionalgroup animations.

8. Click OK.

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ANIMATION 247

Makinganimations frompathsYou can create camera tracksand layer tracks from paths. Apath is defined by a selectedline feature or graphic, and itspurpose is to constrain move-ment along the selection. Acamera track is created bymoving the camera along theselected path. A layer track ismade by moving a layer along apath.

Use the Path destinationoptions for a camera flyby pathto modify the way the camera(observer) travels. There arethree options for moving acamera along a path: move boththe target and observer alongthe path for a flyby, move theobserver along the path withthe current target to point thecamera at an area while it u

Making a camera flybyfrom a path

1. Click a selection tool andselect the line feature orgraphic you want to use as apath.

2. Click Animation and clickCamera Flyby from Path.

3. Optionally, check Apply inreverse order.

The camera will begin at theother end of the path.

4. Optionally, type a value in theVertical offset text box.

An offset defines the heightof the camera.

5. Optionally, slide thesimplification factor.

The simplification factordetermines how much thepath will be generalized forthe animation.

6. Optionally, choose a pathdestination.

Change the path destinationto determine how theobserver and target arepositioned during theanimation.

7. Optionally, uncheck Over-write last imported track.

Disabling this option willallow you to add tracks toprevious ones.

8. Click Import.

Tip

Modifying camerapropertiesWhen selecting flyby mode as thepath destination, click OrientationSettings in the Camera Flyby fromPath dialog box to modify the waycamera azimuth, inclination, androll properties are calculated fromthe path.

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Moving a layer along apath

1. Click a selection tool andselect the line feature orgraphic you want to use as apath.

2. Click Animation and clickMove Layer along Path.

3. Click the Layer dropdownarrow and choose the layeryou want to move.

4. Optionally, check Apply inreverse order.

This option will start the layermoving from the oppositeend of the path.

5. Optionally, type a value in theVertical offset text box.

The vertical offset determinesthe height of the layer.

6. Optionally, slide thesimplification factor.

The simplification factorindicates how much the pathwill be generalized when it isused for the animation.

7. Optionally, uncheck Over-write last imported track.

Disable this to allow addi-tional layer tracks to beimported without overwritingexisting ones.

8. Click Import.

moves along the path, or movethe target along the path withthe current observer to let thecamera follow a virtual pointalong the path in the track. Youcan then move a layer alongthis path to have the camerapoint toward the layer as itmoves.

Tip

Using advanced layerorientation settingsClick Orientation Settings to modifythe way a layer’s azimuth, inclina-tion, and roll properties arecalculated from the path.

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ANIMATION 249

Using theAnimationManagerThe Animation Manager allowsyou to access properties ofkeyframes and tracks. Inaddition, you can access timingproperties and preview youranimation. You can manipulatethese properties, then see theresult using the Time Viewpreview.

Using the AnimationManager to accesskeyframe properties

1. Click Animation and clickAnimation Manager.

2. Click the Keyframes tab.

3. Click the Keyframes of Typedropdown arrow and choosethe type of keyframe youwant to examine.

4. Click the In Track dropdownarrow and choose thespecific track you want toaccess.

5. Click a Keyframe property tochange it.

6. Press Enter.

7. Click Close.

Tip

Why change a track orkeyframe property?Use the Animation Manager tomodify the properties of a keyframeor track. For example, you canchange the camera target’sx-coordinate to move the target to amore pleasing position. Options tochange properties are numerous,allowing you to make youranimation look just as you intend.

Tip

Updating a keyframeTo fine-tune a scene or camerakeyframe in the AnimationManager, select the keyframe youwant to change in the Keyframespage, modify the property in thescene, and click Update. Thekeyframe will be updated to reflectthe change.

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Using the AnimationManager to access trackproperties


2. Click the Tracks tab.

3. Optionally, check View onlytracks of type, click thedropdown arrow, and selectthe type you want toexamine.

4. Click a Track property tochange it.

5. Press Enter.

6. Click Close.

Tip

Changing a track’s priorityIf multiple camera or scene tracksrefer to the same object, they willbe played back according to theirpriority. To change a track’spriority, select the track in theTracks page of the AnimationManager and use the arrow up ordown buttons to move its ranking.If multiple layer tracks refer to thesame layer, their transformationswill be combined.

Tip

What is binding?Tracks are bound to objects. Forexample, a camera track is boundto a particular viewer, and it willplay in that viewer. To change theobject that the track is bound to,click Binding.

Tip

Can I interact with ananimation track?You can manually alter propertiesof a track to allow you, forexample, to navigate duringanimation. Select a track and clickProperties to see those that areavailable for that track. Uncheckthe ones you want to controlmanually.

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ANIMATION 251

Using the AnimationManager to modify timingproperties of tracks


2. Click the Time View tab.

3. Optionally, click the Plus orMinus buttons to change thetime scale.

Reducing the time scalegives you a more detailedview.

4. Optionally, check Viewenabled tracks only.

Using this option shows onlythe tracks that are currentlyenabled. Disable a track inthe Tracks page.

5. Click and drag a greenkeyframe box in a track tochange the time when it willbe played.

Moving a keyframe to a laterpoint in the track will cause itto be played later in theanimation.

Click and drag a keyframe atthe start or end of a track todetermine when that trackwill play relative to others.

6. Click Close.

Timing propertiesin the AnimationManagerUse the Time View page of theAnimation Manager to modifywhen keyframes of one track areplayed relative to others or toorganize how tracks aresynchronized with one another.

When in the Time View page,the timing of all tracks isnormalized to one time unit, andthere is no indication ofduration. Use the durationsetting in the Animation Controloptions dialog box to determinehow long your animation willplay.

Tip

Previewing an animationIn the Time View page, you canexamine your animation by clickingthe display until a vertical red lineappears, then dragging the line topreview the way your animationwill play.

Tip

Why are my layer trackscolored differently?In the Time View page, group layertracks are color-coded to indicatetheir visibility. Light green meansthe layer is visible; red indicatesthat the layer is invisible; and paleyellow lets you know that the layeris semitransparent, or intransitional visibility.

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Saving an animation in ascene document


An existing scene documentwill be appended with theanimation, or if none exists,you will be prompted toprovide a name for a newdocument that will containthe animation.

Saving ananimationAn animation that is created ina scene or globe will be storedin the document when it’ssaved. Animation tracks canalso be saved into an indepen-dent .asa or .aga file. Anotherway to save an animation is toexport it to a .avi or Quick Time.mov file.

In order to be able to export.mov videos, you’ll need tohave Quick Time installed onyour computer.

Saving an animation byexporting tracks to anArcScene Track file

1. Click Animation and clickSave Animation File.

2. Click the Save in dropdownarrow and choose a location.

3. In the File name text box,type the name you want togive the animation file.

4. Click Save.

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ANIMATION 253

Exporting an animationto a video file

1. Click Animation and clickExport to Video.

2. Click the Save in dropdownarrow and choose a location.

3. In the File name text box,type the name of the videofile you want to create.

4. Click the Save as typedropdown arrow and selectthe type of video file youwant to create.

You can export a .avi or .mov.

5. Click Export.

A video file of the givenname and type is created inthe specified location.

Tip

Using advanced videooptionsTo access frame rate and videoquality properties, click Options onthe Video Export dialog box.

Tip

Preventing extraneouswindows from appearing invideo filesMake sure that when you exportyour animation to a video file youmove other windows away sonothing obscures the viewer that isplaying the animation. Otherwise,they may appear in the exportedfile.

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Sharinganimations:Loading anArcScene orArcGlobeAnimation fileYou can load an ArcScene orArcGlobe Animation file intoany scene or globe. However,when attempting to load ananimation into a new document,care must be taken to ensurethat the animation applies to thedocument. If an animation trackrefers to an item that doesn’tapply to the document, thetrack will not play. For example,if you’ve created an animationcontaining a track that refers toa certain layer in a document,that layer must be present in thenew document and must be inthe same location in the TOC.Because a layer track refers to alayer by noting its ranking inthe TOC, the track may animatean incorrect layer or may not u

Loading an ArcSceneAnimation file

1. Click Animation and clickLoad Animation File.

2. Browse to the ArcSceneAnimation file you want toload.

3. Click Open.

Tip

Identifying ArcSceneAnimation filesArcScene track files are appendedwith the .asa extension. ArcGlobetrack files are appended with the.aga extension.

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ANIMATION 255

be enabled to play if the rankingin the new document’s TOC isdifferent. Also, if a track refersto a viewer that doesn’t exist inthe new document, that trackwill not play. In addition, ifyou’ve created a camera track ina document’s extent and wantto play it in a new document,make sure the extent of the new3D view is the same, or elseyour track might move thecamera in an area where there isno data. This is because acamera track is defined in partby a document’s extent.

Tip

Using animations stored ina scene or globe documentLoad the document with animationinto ArcScene or ArcGlobe as youwould any other document. Modifythe name you give to animateddocuments to let others know thatthey contain animation.

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3D symbology 9• What is a 3D symbol?

• Using 3D symbols

• Using 3D styles

• Making 3D symbols

• The 3D Symbol Property Editor

• Altering the 3D placement of a symbol

• Offsetting a 3D symbol

• Scaling the size of 3D symbols

• Using 3D styles to assign symbology

• Symbolizing points with 3D symbols

• Symbolizing lines with 3D symbols

• Symbolizing polygon fills with 3Dsymbols

• Saving the current styles

• Organizing 3D style contents

• Creating and modifying 3D symbolsand elements

Using 3D symbology allows you to provide a sense of realism to your 3Ddocuments or render cartographic symbols in 3D. You can use 3D symbols todisplay features as 3D objects or display your map symbols in 3D.

For example, instead of symbolizing a house as a simple point, you couldchoose to symbolize it with a 3D model of a particular style of home, providingrealism to your document. Or, you might choose to display a layer ofrecreation use symbols by selecting 3D versions of the symbols for a morevivid effect. In addition, you could symbolize a roads layer as textured stripscreating a realistic road network. Finally, you might add a texture to a surfaceto provide a realistic ground surface to your scene or globe.

3D symbology lets you create documents that dramatically enliven your dataand provide stunning representations of your 2D maps. Using 3D symbologyallows you to depict real-world scenarios that can be as geospecific, or“visually true”, as you dictate while also giving you the option to portray yourdata geotypically, or “stylistically true”. You’ll be able to import your existingOpenFlight (.flt), 3ds max* (.3ds), or Virtual Reality Markup Language(VRML*) models into ArcGIS, then symbolize features with these models, orchoose to select symbology from a rich set of included 3D styles that containmodels, cartographic symbols, and 3D geometric shapes.


What is a 3D symbol?

A 3D symbol is a 2D symbol with extended properties. Theseproperties enhance 2D symbols so that they can be viewed in 3Din an ArcGIS 3D application.

While a 2D symbol has dimensions in the x and y directions, a 3Dsymbol has the additional property of a dimension in the zdirection. Thus, a 2D point symbol is analogous to a 3D spheresymbol, a square-shaped 2D symbol is analogous to a cube-shaped 3D symbol, and a 2D line symbol can be analogous to atube-shaped 3D symbol.

3D symbols can also be more complex than simple geometricshapes. A 2D picture fill symbol, whose pattern is applied as a fillto a 2D polygon, is analogous to a 3D texture fill symbol. A 3Dtexture fill symbol is a picture fill symbol that has awareness ofits real-world size, and can be mapped on to a geometry withproper scaling. Points may also be symbolized by representationsof real-world objects (3D models) as, for example, a set of pointsindicating dwelling locations being symbolized by existing 3Dmodels of houses.

Types of 3D symbols

A point can be symbolized in 3D by a simple 3D marker such as acube or a cone, a 3D character marker based on a system font, ora 3D marker as imported from a 3D model. A line can besymbolized in 3D by using a 3D simple line symbol, such as atube or a strip; or a texture line symbol, such as a texturesymbolizing a road. A polygon or surface can be symbolized byusing a 3D texture fill symbol, for example, a texture resembling ageotypical feature such as grass. These options allow you to

Example of 2D features on the left and the analogous 3D representationson the right

Existing points, on the left, symbolized by 3D model houses, on the right

3D symbols used to portray realism

3D SYMBOLOGY 259

render realistic 3D worlds. For example, you may have an existingdocument that could be made more visually realistic bysymbolizing points representing a housing tract by 3D models ofhouses, then symbolizing the roads in this tract by using atextured line symbol that models pavement. In addition, youmight use a grass texture to symbolize a polygon feature classshowing city parks.


Using 3D symbols

Making geotypical documents

A geotypical symbol is a model with realistic properties that areused to portray a certain style. A set of geotypical models mightshow a generic style or theme, such as “Capecod Houses”, withdifferent properties such as “1 story” or “2 story”. 3D Analystcomes with 3D styles that let you symbolize points, lines, andpolygons with generic 3D symbols such as typical houses,textured roads, and fills. You can use these symbols to createrealism, while still being abstract enough to not imply specific,actual objects. Use geotypical symbols to model a proposedhousing tract or in existing areas where it isn’t necessary to showreal-world objects. Using geotypical 3D symbols, you can makedocuments that mimic real-world characteristics but don’t implyvisual truth.

Making geospecific documents

A geospecific symbol is a model that is based on a real-worldobject. An example is a model of the White House in Washington,D.C. You can symbolize features with objects that are based onreal-world objects. For example, if you have existing 3D models ofbuildings that exist in an area, you can import them, then renderyour point feature class with the objects you’ve imported. Youcan also import any textures that you may have, such asvegetation or wall textures. You can import these models intostyles or as needed to symbolize features independent from astyle.

Making 3D maps

You can create dramatic maps that are rendered with 3Dsymbology. These maps may use a map’s 2D symbology as aguide, then display the symbols in 3D. For example, points can bedisplayed as spheres, lines as strips, and polygons as texturedobjects. In addition, you might choose a 3D character marker to

render font-based characters in 3D. You can use these 3Drepresentations to bring new perspectives to your maps.

2D representation (left) and 3D representation of a weather map

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Using 3D styles

3D styles

Styles are sets of particular symbols with preset characteristics.These symbols are categorized thematically, then saved withproperties, such as size and color, that make it convenient to usethem. 3D styles work the same way as 2D styles but contain 3Dsymbols commonly used in 3D Analyst. They may, in addition,store some real-world information about their sizing.

3D Analyst comes to you with 3D styles that are ready to use.These styles contain both simple geometric shapes as well asgeotypical models. In addition, you can create your own symbols,then make your own styles containing these symbols. You canalso construct styles from existing symbols.

Styles are a convenient way of storing symbology that youcommonly use. 3D Analyst provides styles that help yousymbolize common scenarios and also provides the flexibility foryou to create your own styles by making them from existingsymbols or importing them.

See ‘Working with styles and symbols’ in Using ArcGIS ArcMapfor more detailed information on working with styles and the StyleManager.

3D point styles

When you open the symbol selector of a point’s symbology,you’ll see the 3D styles available by noting those prefixed with“3D”. Some of these styles contain common 3D character markersymbols with convenient sizes and colors. Other 3D stylescontain simple geometric shapes such as spheres, cubes, andtetrahedrons. Yet other 3D styles contain models such asbuildings, street furniture, trees, and vehicles with real-worldsizing information.

Use 3D point styles to render simple geometric shapes such asspheres or cubes. Or use them to make building models based on

point feature classes. You can also symbolize points as modelssuch as houses, vehicles, or street furniture.

3D line styles

Similarly, styles are available for line symbology. You can choosefrom styles that contain simple geometries, such as tubes orstrips, or styles that include textures of fences, walls, roads, andwalkways.

Use 3D line styles to show roadways or fences. You might alsoshow a sewer network or pipe workings symbolized as tubes.

3D polygon fill styles

You can use 3D styles for polygons that allow you to depict theirfills as a variety of textures, including, for example, those that arevegetative or man-made.

Example of 3D styles available for point feature classes


You can use these 3D textures to model the grass in a park or thepavement of a parking lot. You might also use a style texture tosymbolize a surface, portraying the ground as a set of groundcovers.

3D styles are the quick way to symbolize common 3D features.Use them as a shortcut to create realistic models or abstract 3Dworlds. Next, you’ll see how you can import and create your own3D symbols.

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Making 3D symbols

You can make your own 3D symbols by composing them fromexisting symbols or by importing them as 3D models from otherformats. In this section you’ll learn how to do both.

Constructing your own 3D symbols

You can create your own 3D symbols to symbolize a particularfeature or add to a style’s contents. You might create a compositesymbol by combining unique symbols into one. See ‘Creatingnew symbols and map elements’ in the ‘Working with styles andsymbols’ chapter in Using ArcGIS ArcMap.

Importing 3D models as symbols

You can import OpenFlight (.flt), 3ds max* (.3ds), or VRMLmodels as 3D symbols. Use this feature if you have existing 3Dmodels that you’d like to use in 3D Analyst. You can import thesemodels when symbolizing a feature, or you can import them intoan existing or newly created style.

OpenFlight models can be created using MultiGen–ParadigmModelBuilder 3D*. You can use ModelBuilder 3D to quicklygenerate 3D models of real-world buildings, objects, andvegetation for incorporation into an interactive display of 3D GIS.To create .3ds models, you can work in Discreet 3ds max, or use@Last Software SketchUp* as a tool for creating 3D models,then export them to .3ds format.


The 3D SymbolProperty EditorWhen using 3D symbols in theSymbol Property Editor, somefeatures specific to 3D becomeavailable that are common to all3D symbols, such as a 3Dpreview, 3D placement, and 3Dthreshold. In this section, you’lllearn how to accomplish tasksusing these features.

Opening the 3D SymbolProperty Editor

1. In the TOC or the symbologyLayer Properties page, clickthe symbol whose propertiesyou want to change.


The Symbol Property Editorappears.

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Altering theplacement of a3D symbolYou can alter the placement of a3D symbol in relation to thefeature it’s symbolizing. Youcan set the origin of a 3Dsymbol, then offset thisnormalized origin. In addition,you can alter the rotation of asymbol in the three axes thatdefine 3D space.

When you set the origin of a 3Dsymbol, you’re indicating whereon that symbol you want theorigin to be. For example, thedefault location of the origin fora sphere is at its center. You canset, or normalize, the origin tobe at its edge.

Setting the origin of a 3Dsymbol

1. In the Symbol Property Editor,click the 3D Placement tab.

2. Slide the normalized originoffset slider for the axis youwant to modify to the positionyou want the origin to bewithin the symbol.

3. Click OK.

The origin is moved to thenew position in the 3DPreview window.

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Setting an offset for anormalized origin of a 3Dsymbol

1. In the Symbol PropertyEditor, click the 3D Place-ment tab.

2. Type an offset for the axisthat you want to modify.

3. Click OK.

The normalized origin of thesymbol is adjusted in the 3DPreview window.

Offsetting a 3DsymbolAfter you are satisfied with thenormalized origin of a 3Dsymbol, you may wish toindicate an offset for thesymbol. You’ll use real-worldunits to set offsets of 3Dsymbols.

Tip

Specifying an offsetwithout typingInstead of typing in a number forthe offset, you can use the Up andDown buttons on the right side ofthe Offset text boxes.

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Setting the rotation of a3D symbol

1. In the Symbol Property Editor,click the 3D Placement tab.

2. Type an angle of rotation indegrees for the axis you wantto modify.

3. Click OK.

The symbol is rotated alongthe axis in the 3D Previewwindow.

Tip

Specifying a rotationwithout typingInstead of typing in a number forthe rotation angle, you can use theUp and Down buttons on the rightside of the Rotation angles textboxes.

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Scaling the size of a setof 3D symbols in a layer

1. Right-click a layer symbol-ized with 3D symbols andclick Scale 3D Symbols.

2. Move the slider to the left orto the right to decrease orincrease the symbol’s scaledsize, respectively.

3. Optionally, click Suggest tooffer a scale based on thelayer’s extent and thesymbol’s size.

4. Click OK.

Scaling the sizeof 3D symbols3D Analyst stores models in itsstyles with real-world sizes andattempts to provide sizingoptions for other symbols thatwill suit your needs. However,you may find that after yousymbolize a feature, you’ll needto adjust its scale in yourdocument. The Scale 3DSymbols dialog box, accessedfrom a layer’s context menu,allows you to do this using on-the-fly feedback.

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Changing the dimensionsof the symbol axes

1. In the Symbol Property Editor,click the 3D CharacterMarker, 3D Marker, or 3DSimple Marker tab.

2. Optionally, uncheck Keepaspect ratio to change thedimensions of individualaxes.

3. Under Dimensions, type avalue in the text box for theaxis you want to modify.

4. Click OK.

The dimensions of thesymbol are modified in the3D Preview window.

Tip

Specifying a dimensionwithout typingInstead of typing in a number forthe size along an axis, you can usethe Up and Down buttons on theright side of the Width (X), Depth(Y), or Size (Z) text boxes.

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Using 3D stylesto assignsymbologyStyles contain symbols withpreset properties that you mightuse often. 3D styles offergeometric primitives as well asmodel libraries.

Symbolizing a featurewith a symbol in a style



3. Click the Symbol button.

4. Click More Symbols and clickthe style you want to use.

5. Optionally, click the Categorydropdown menu and click thecategory of the style youwant to use. u

Tip

A shortcut to the SymbolSelectorYou can invoke the Symbol Selector,the dialog box that lists symbols instyles, by clicking the feature classsymbol in the table of contents.

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6. Click the symbol you want touse.

7. On the Symbol Selectordialog box, click OK.


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Symbolizingpoints with 3DsymbolsPoints can be symbolized as 3Dcharacter markers, 3D markers,and 3D simple markers. You cancreate 3D symbols that usefonts on your system, choose3D markers from existing styles,or import them from OpenFlight,3D Studio Max*, or VRML. 3Dmarkers are analogous to 3Dmodels. Finally, you cansymbolize points as 3D simplemarkers, which are 3D primi-tives, such as spheres andcubes.

Symbolizing a point as a3D character marker notincluded in a style

1. In the TOC, click the symbolof the point feature class youwant to modify.


3. Click the Type dropdownmenu and click 3D CharacterMarker Symbol.

4. Click the font dropdownmenu and click the font youwant to use.

5. Click the Character buttonand click the symbol youwant to use.

6. Optionally, click the Colordropdown menu and click thecolor you want to use.

7. Click OK.

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Symbolizing a point as animported 3D marker


2. Click Properties on theSymbol Selector dialog box.

3. In the Type dropdown menu,choose 3D Marker Symbol.

4. Browse to the model youwant to use and click Open.

5. Click OK.

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Symbolizing a point as a3D simple marker notincluded in a style



3. Click the Type dropdownmenu, and click 3D SimpleMarker Symbol.

4. Click the Style dropdownmenu, and click the shapeyou want to use.


6. Optionally, adjust the Qualityslider for shapes with curvedsurfaces.

7. Click OK.

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Choosing a quality levelUse a higher quality level if youdon’t have many features tosymbolize and a lower quality levelif you have many features. Higherquality renders at the expense ofperformance.

3D SYMBOLOGY 275

Symbolizing lineswith 3D symbolsYou can symbolize line featuresas 3D simple lines or 3Dtextured lines. Use 3D simplelines to symbolize lines as 3Dgeometric shapes, such astubes and walls. Use 3Dtextured lines to turn your linework into realistic roads,fences, or walkways.

Symbolizing a line as a3D simple line notincluded in a style

1. In the TOC, click the symbolof the line feature class youwant to modify.


3. Click the Type dropdownmenu and click 3D SimpleLine Symbol.


5. Click the Style dropdownmenu and click the shapeyou want to use.

6. Optionally, slide the Qualityslider to your desired qualitylevel.

7. Click OK.

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Symbolizing a line as a3D texture line with animported 3D texture

1. In the TOC, click the symbolof the line feature class youwant to modify.


3. Click the Type dropdownmenu and click 3D TextureLine Symbol.

4. Browse to the texture youwant to use and click Open. u

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5. Optionally, check Verticalorientation to flip the geom-etry and texture vertically.

6. Click OK.

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Symbolizing a polygonwith an imported 3Dtexture fill symbol

1. In the TOC, click the symbolof the polygon feature classyou want to modify.


3. In the Type dropdown menu,choose 3D Texture FillSymbol.

4. Browse to the texture youwant to use and click Open. u

Symbolizingpolygon fills with3D symbolsPolygon fills and TIN trianglescan be symbolized with 3Dsymbols using the 3D TextureFill Symbol option. Use thisoption to realistically displayland use features or otherpolygonal areas.

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5. Optionally, type an angle youwant to use to rotate thetexture.

6. Optionally, type a number fora specific axis to scale thetexture in that direction.

7. Click OK.

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Saving thecurrent stylesYou can easily create a newstyle containing all the ele-ments, symbols, and symbolproperties used in yourdocument.

Create and modify 3D elementsand symbols as you designyour document, then saveeverything into a style.

Exporting styles allows you tosave 3D elements and symbolsfrom many styles into a singlestyle.

Tip

How are symbols stored ina 3D document?The items you draw in 3D—symbols and elements—are copiedinto the document. Therefore, youdon’t need the original referencedstyles to open and draw thedocument again.

Tip

Can I create a style from adocument without anyreferenced styles?If you need to modify the symbols ina document and don’t have theoriginal styles, you can create anew style by exporting the existingdocument elements and symbols.

Exporting the currentdocument styles to a newstyle

1. Click Tools, point to Styles,and click Export Scene (orGlobe) Styles.

2. Navigate to where you wantto save the new style.

By default, the browser is setto your Styles folder.

3. Type a style name.

4. Click Save.

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Organizing 3Dstyle contentsThe Style Manager dialog boxlets you organize styles andtheir contents. You can cut,copy, paste, rename, and modifyany style contents. You canalso create new styles andsymbols.

You can create a new style andcopy your personal stylecontents as well as othersymbols from other existingstyles. Or you can import 3Dmodels into styles.

You can easily distinguishwhich folders contain elementsand symbols, which can bemodified, and which are empty.

Tip

Finding the Styles foldersBy default, the ESRI Styles folder isin the \Bin\Styles folder whereArcGIS is installed. Your personalstyle folder is in your user profilelocation, for example,C:\Documents andSettings\<user>\ApplicationData\ESRI|ArcMap.

Creating a new style

1. Click Tools, point to Styles,and click Style Manager.

2. Click Styles and click CreateNew.

3. Navigate to the Styles folder.

4. Type the name for the newstyle you’re creating.

5. Click Save.

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Deleting style contentsRight-click any map element orsymbol and click Delete from thecontext menu.

There is no undo for delete, so youmay want to move the element toanother folder as a backup ratherthan delete it.

Tip

What’s a symbol’scategory?When you save a symbol, you canspecify a name and a category forclass distinction. The category canbe used to create thematic classifi-cations. You can also createsubcategories of styles. Categoriescan be viewed in the Style Managerdialog box.

Copying and pastingstyle contents

1. Click Tools, point to Styles,and click Style Manager.

2. Click the style folder whosecontents you want to view.

3. Right-click an element andclick Cut or Copy.

4. Click another style folder ofthe same type.

5. Right-click in the symbolcontents window and clickPaste.

You can only paste into stylefolders that are the same typeas the folder from which theelement was copied.

6. Type a new name for theelement.

You can change the namelater by using Rename on thecontext menu.

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Creating andmodifying 3Dsymbols andelementsYou can use the Style Managerdialog box to create newsymbols or to modify anexisting symbol.

To set or modify properties ofan element or symbol in a style,double-click it in the contentswindow of the Style Manager.This opens a property dialogbox and allows you to definethe appearance of the elementor symbol and save changeswithin the style.

Since symbols and elements areorganized by type, you create anew symbol or element by firstidentifying the type, then byselecting the appropriate folder.Then, when you choose tocreate a new symbol or element,the properties you can choosefrom are only associated withthat symbol or element type. u

Tip

Using Microsoft® Access toedit your stylesA style is a database. You can useAccess to edit names, check yourspelling, control sorting, andcomplete other tasks.

Creating a new symbol inthe Style Manager

1. In the style tree, click thesymbol folder in which youwant to create more symbols.

2. Right-click in the open spacein the Symbol contentswindow, point to New, andclick the type of symbol youwant to create.

Use the Symbol PropertyEditor to create the symbolyou want and click OK.

3. Name the new symbol.

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Layers appear in the listaccording to when they aredrawn. Therefore, the bottomlayer will be covered by thelayer listed above it.

By adding or working withlayers, you can enhance thesymbols that already exist orcombine them to make newsymbols. The layers you usecan be a mixture of differentsymbol types and properties,such as color, width, and offset.Turning on or off a layer affectswhich layers will be viewed inthe preview. Locking andunlocking a layer does notaffect your capabilities in theSymbol Property Editor;however, it does affect theability to change the color inthe Symbol Selector you accessthrough the Layer Properties.There, if you change thesymbol color, only the unlockedlayers will change to the newcolor.

Tip

Using a shortcut to theSymbol Property Editordialog boxInstead of clicking the Propertiesbutton on the Symbol Selectordialog box, you can click thePreview window on the SymbolSelector dialog box.

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285

3D graphics and text 10• The 3D Graphics toolbar

• 3D text

• Changing properties of selectedgraphic elements

• Changing defaults for the waygraphics appear

• Graphics layers

The information portrayed in your 3D documents isn’t always enough tomake your point. In some cases you will want to add text and other graphics,such as points, lines, and polygons, to bring attention to certain features oremphasize important areas. For example, you might define a study area byenclosing it with a line or polygon boundary or label buildings with textindicating their names.

You can use the 3D Graphics toolbar to help you accomplish these tasks.The 3D Graphics toolbar gives you the ability to digitize 3D text, points, lines,and polygons based on elements in your display. The toolbar gives you theflexibility of dictating how these graphics are drawn by defining properties,such as shape, color, font, location, and size.


Digitizing a 3D pointgraphic

1. Click the New Marker button.

2. Click the point on the surfaceor object you want to digitize.

The 3D GraphicstoolbarThe 3D Graphics toolbar allowsyou to make 3D point, line,polygon, and text graphics.These graphics will draw basedon objects in the view. Usingthe toolbar, you can digitizepoints that might show areas ofinterest, lines that may encom-pass an area, polygons that fillan area, or text that mayannotate parts of your studyarea.

A point graphic is drawn atthe location you digitized.

You can set the default pointto be any symbol you want.

Turning on the 3DGraphics toolbar

1. Right-click in the gray areawhere toolbars appear andclick 3D Graphics.

The 3D Graphics toolbarappears.

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Digitizing a 3D linegraphic

1. Click the New Line button.

2. Click the first point on thesurface or object you want todigitize.

3. Click any additional vertices,double-clicking on the lastone.

A line graphic is drawnbetween the vertices youdigitized.

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Line and surfaceintersectionYou can make a digitized lineconform to a surface by digitizingmore vertices along its length, ormake it intersect the surface bydigitizing fewer vertices. Since theline digitizing tool is not a profilingtool (heights are obtained atdigitized points and not interpo-lated between), the resulting linesmay not conform to the surface. Tomake lines conform to the surfacemore closely, digitize more points.


Digitizing polygongraphics

1. Click the New Polygonbutton.

2. Click the first point you wantto digitize on the surfaceobject.

3. Click any additional verticesyou want to create, double-clicking on the final point.

A polygon outline appears,defined by the vertices youdigitized.

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Why doesn’t the digitizedpolygon conform to thesurface?When you digitize a polygongraphic, only the vertices of theedges you indicated by digitizingare interpolated from the surfaceor object. Therefore, in cases ofvarying topography, polygoninteriors may not conform tosurfaces. A special case where apolygon will conform is in a flatarea. If you find that polygoninterior nonconformance is aproblem, you may want to set thedefault polygon fill to be No Color.If you need to show polygons withno color fill, see ‘Changing theproperties of selected graphicelements’ in the upcoming pages.


Digitizing text

1. Click the 3D Text tool.

2. Click the location on thesurface or object where youwant the text to be placed.

3. Type the text you want todisplay and press Enter.

3D text appears at thelocation you clicked.

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Changing the color of aselected graphic

1. Click the Select Graphicstool.

2. Click the graphic elementyou want to change.

3. Click the 3D Text Colordropdown arrow for text, theFill Color dropdown arrow forpolygon graphics, the LineColor dropdown arrow forlines, or the Marker Colordropdown arrow for points.

4. Click the color you want touse.

The selected graphic ischanged to the color youchose.

Changingproperties ofselected graphicelementsYou can change the way thatexisting graphics appear. If agraphic element is selected,then any change you makeusing the properties buttonswill be honored.

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Changing other drawingpropertiesIf you select a graphic and click onthe left side of the Color dropdownarrow, you’ll invoke dialog boxesthat allow you to set additionalproperties.

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Changing the defaultdrawing properties of a3D point, line, or polygongraphic

1. Click Graphics and clickDefault Symbol Properties.

2. Click the Marker, Line, or Fillbutton to set default proper-ties for a point, line, orpolygon symbol, respectively.

3. Click the symbol you want touse.

4. Optionally, click Color or Sizeto change the color or size ofa symbol.

5. Optionally, click Properties toaccess additional symbolproperties.

6. Click OK.

7. Click OK.

Changingdefaults for theway graphicsappearIf you want your graphics to bedrawn a certain way by default,you can do so by setting thedefault properties for points,lines, polygons, and text.Properties that you can set asdefault include color, sizing,and font. You set the defaultproperties by choosing asymbol that you would like tobe drawn by default. If youwant the default symbol toappear differently, you canchange its properties, in turn.For example, when you chooseto change the default propertiesfor a line symbol, you’ll invokethe Symbol Selector dialog box.At this point you can select anyline symbol from any availablestyle as the default symbol. Ifyou want the default to be analtered version of one of thesesymbols, you’ll invoke theproperty pages for that symboland change properties to suityour needs.

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Changing the defaultdrawing properties of a3D text graphic

1. Click Graphics and clickDefault 3D Text Properties.

2. Click the 3D Text tab to setdefault properties, such asfont, color, or orientation.

3. Click the Size and Positiontab to change default sizingoptions.

4. Click OK.

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Graphics layersDocuments can contain layersthat are made up of graphics.Graphics in a document can bestored in one layer, such as thedefault graphics layer, or inmultiple layers. If you begin tocreate graphics withoutdesignating a new graphicslayer as a target, the graphicswill be stored in the defaultgraphics layer. Optionally, youcan set 3D graphics to bestored in a graphics layer thatyou can create, name, and saveas a layer file.

Creating a new graphicslayer

1. Click Graphics and click NewGraphics Layer.

A new graphics layer iscreated in the TOC.

Tip

Naming graphics layersName a graphics layer listed in theTOC just like any other layer.Select the layer in the TOC, click itagain, and type the name you’d liketo call the layer.

Setting the target layer ofnew graphics

1. Click Graphics, point toActive Graphics Layer Target,and click the graphics layeryou want to set as the targetfor newly created graphics.

All new graphics you createwill now be added to thetarget graphics layer.

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Section 2

ArcGlobe

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IN THIS CHAPTER

11• What can you do with ArcGlobe?

ArcGIS 3D Analyst enables effective visualization and analysis of surfacedata. Using 3D Analyst, you can view a surface from multiple viewpoints,query a surface, determine what is visible from a chosen location on asurface, and create a realistic perspective image by draping raster and vectordata over a surface. The core of the 3D Analyst extension is the ArcSceneand ArcGlobe applications. This section describes and demonstrates howArcGlobe provides the interface for viewing multiple layers of GIS data andcreating and analyzing surfaces.

With 3D Analyst and ArcGlobe, you can

• Use several forms of geographic data including vector data (buildings,parcels, roads, power lines, water hydrants, and soils) and raster data(digital elevation models [DEM], satellite imagery, digital orthophotoquadrangles [DOQ], and aerial photography).

• Manage and navigate through extremely large databases (terabytes).• Extrude two-dimensional representations to three dimensions.• Create three-dimensional fly-through animations.• Perform analyses such as overlay, viewshed, and buffer.• Use GIS tools and functions in a 3D environment.• Apply various data layer effects such as transparency, lighting, shading,

and depth priority.

• View multiple perspectives simultaneously.

Introducing ArcGlobe

298 USING ARCGIS ARCGLOBE

What can you do with ArcGlobe?

Visualizing complex data, and more

ArcGlobe lets you work with your GIS data in 3D perspectivewhether its extent is local or worldwide and whether its size islarge or small. The interactive seamless display mechanism inArcGlobe allows a smooth visual transition between datasets.Individual datasets are merged into one of three unique globallayers categorized as floating, draped, or elevation. The drapedand elevation layers are the result of their constituent pieces ofdata; additional data increases the resolution of each global layer.

You can effortlessly zoom from a view of the whole earth to yourlocal site using simple navigation tools. ArcGlobe controls thecaching and tiling of levels of detail of your data using distanced-based (scaled) dependencies, allowing you to load large datasetsinto a globe and easily navigate and interact with them. Themultitasked input and output processes in ArcGlobe allow you tonavigate while the details of your data are loaded into the

display; you don’t have to wait for details to be paged into thedisplay before you continue your navigation.

The powerful display pipeline in ArcGlobe uses temporary filesgenerated as you need them to improve the speed of display. Thismechanism allows you to work with vast amounts of data as ifthey were small and simple. Application- and layer-level optionsallow you to choose caching mechanisms that work best for you.The flexibility of the caching options provide the opportunity foryou to customize the way ArcGlobe deals with large volumes ofdata.

To enhance your visualization experience, you can use multipleviewers to view data in different parts of the globesimultaneously, allowing you to gain perspective from different

INTRODUCING ARCGIS ARCGLOBE 299

view points. You can also use specialized toolbars, such as the3D Effects and Animation toolbars, to help you customize yourvisualization experience.

Use your existing GIS data

As long as your data has a spatial reference, you can add it toArcGlobe. ArcGlobe uses the world geodetic system 1984 (WGS-84) geographic datum to display data on a sphere. If your datauses a datum other than this, it will be transformed into the WGS-84 format for display.

You can load virtually any type of data into ArcGlobe that youwould in any other ArcGIS application. Most types of raster andvector data that are spatially referenced can be loaded into aglobe. The spatial reference indicates where the data will appearon the globe.

ArcGlobe is loaded with global and select local scale data rightout-of-the-box giving you a base from which to build your ownglobes. For example, you might enhance the base ArcGlobeelevation and imagery data with your own local elevation, image,and vector data, allowing you to zoom from a view of the entireearth down to your detailed local site.

Utilize large volumes of data

ArcGlobe can display substantial amounts of data quickly andeffectively. The data can be widespread or limited in extent withhighly detailed or coarse resolution.

Start working with ArcGlobe immediately

ArcGlobe ships with data already loaded. When you start theArcGlobe application, you’ll see a base globe that contains aworldwide image and a countries feature class. In addition,supplemental data is provided in the ArcGIS 3D Analyst and

ArcGlobe Data media kit that contains a comprehensive set ofimagery and elevation data. You can start working with ArcGlobeby using the navigation tools or by using a geographic indexservice, the ArcWeb Place Finder, to find locations by simplytyping the name of the place you want to find.

Explore areas of small extent

Because ArcGlobe is able to view a globe at its full extent and at adetailed, magnified view, you can view your data even if it’s asmall area. You have the whole globe as a reference to your data’slocation, and when you zoom in, you have the globe surface as abackground to your data.

Explore areas of large extent

Since ArcGlobe can load worldwide data into one GlobeDocument, you can utilize data that covers the whole world,zooming into the detail as you desire.

300 USING ARCGIS ARCGLOBE

Explore discreet areas spread worldwide

ArcGlobe presents your data as three global layer categories thatare resolved to a higher degree at geographic locations whereyou’ve added more detailed data. In this way, your globe has ahigh degree of resolution at the areas in which you’re interested.You can examine your study area in one location and thennavigate to another location where you’ve added data.

Make animations

ArcGlobe includes a complete set of animation tools, enablingyou to create flybys, animated objects, time series progressions,and more. You can export these animations as QuickTime movies(.mov) or Audio Video Interleave movies (.AVI) that you can sharewith others including those who don’t have an ArcGIS system.

Make 3D maps or real-world models

ArcGlobe incorporates 3D symbology that lets you displayabstract 3D geometric primitives as well as realistic typical orspecific models. This means that you can display standardcartographic symbols in 3D and real-world 3D models that youconstruct or choose to use from the rich 3D Style Librariesincluded with ArcGlobe. The wide variety of 3D symbols give youa high degree of flexibility in customizing your globes.

Getting started

In the next chapter you’ll learn how to display and navigate yourdata and perform analytic operations. You’ll find ArcGlobe to be apowerful and significant means of using your GIS data, while atthe same time, a simple and easy to use ArcGIS application.

IN THIS CHAPTER

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Using ArcGlobe 12• Data you can use with ArcGlobe

• Default layers

• Creating a new globe

• The ArcGlobe document

• Table of contents and layers

• Navigating

• Globe layer properties

• Layer cache properties

• Globe properties

• Application-level options

• Caching concepts

• And more

ArcGlobe gives you a new and unique way to view and analyze your GISdata. Spatially referenced data is placed on a 3D globe surface, displayed inits true geodetic location. You can manipulate the globe and investigate andanalyze its data while viewing the globe as a whole or by region. You can viewdata covering a global extent and seamlessly zoom in to highly detailed,localized data. ArcGlobe allows efficient display and query of raster data, andit is integrated to function with the ArcGIS geodatabase while providingsupport for analysis in the geoprocessing environment.

ArcGlobe includes a comprehensive set of imagery and additional data isavailable on DVD, including elevation data for the entire earth. To help youget started and to provide a backdrop for layers you’ll add, ArcGlobe startswith a set of default layers. Then, depending on how you want to useArcGlobe, the default layers can be changed, replaced, or completelyremoved.

Take some time to work through the ArcGlobe tutorials in Chapter 2, thenconsult this chapter for answers to questions you may have.

Much of the functionality that is common to ArcGlobe and ArcScene isdiscussed in Section 1 of this book.


Types of data you can use with ArcGlobe

Elevation data

You use elevation data to give your globe relief. You can useelevation data as a source of base heights to drape other data.Different sets of elevation data are used in conjunction with oneanother. Multiple elevation models of varying extent andresolution are automatically seamed together as one logicalsurface. The more detailed data you add, the more detailed thefinal surface becomes. Elevations can be calculated from anyspatially referenced raster supported by ArcGIS.

Image data

You can add spatially referenced images to ArcGlobe. The spatialreference will dictate where on the globe the data appears. If theimages have shared extent, the image with the higher degree ofresolution will take priority when displayed. Examples of data youmight use include satellite imagery, scanned maps, andcategorical data, such as land cover. The images added toArcGlobe are automatically draped on any elevation data with thesame extent if the image is added as a draped layer.

Feature data

Feature data with a spatial reference can be added to ArcGlobe.You can add 3D features or make features render in 3D by settingelevation and extrusion properties. You can then perform analysison the features, such as selection, or find a particular feature in afeature class.

Globe surface without terrain (left) and with terrain from elevation data(right)

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Default layersYou’ll notice that when youstart ArcGlobe, there areexisting layers in the table ofcontents. These are the defaultlayers that are included withArcGlobe and are meant to be abackground or starting point atwhich you can begin usingArcGlobe. You can use thedefault layers provided, provideyour own, or choose not tohave any default layers.

Setting ArcGlobe to openwithout any defaultlayers


2. Click Default Layers.

3. Check Don’t use any defaultlayers.

4. Click OK.

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User-defineddefault layersYou can define the defaultlayers that are in the table ofcontents when you startArcGlobe. These are known asuser-defined default layers. Youindicate which layers you’d likeset as default by clicking abutton that takes a snapshot ofwhat’s in the table of contentsat that time. Your choice ofuser-defined default layers willbe remembered by the system,so you can toggle between theother choices and return to theoption of loading your layersby default without having tospecify them again.

Setting ArcGlobe to openwith default layers youprovide



3. Check Use my choice ofdefault layers.

4. Optionally, click Make DefaultLayers From Current Docu-ment.

This captures the layers inthe table of contents as yourdefault layers.

5. Click OK.

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System defaultlayersWhen you start ArcGlobe,you’ll see a set of default layersin the table of contents. Theseare the system-supplied defaultlayers. You can always chooseto use them again after you’veset other choices.

Setting ArcGlobe to openwith the default layersoriginally provided

1. Click Tools and click Op-tions.


3. Check Use the default layersthat come with ArcGlobe.

4. Click OK.

Tip

Two sets of default layersOnce you create user-defineddefault layers, you’ll have two setsof default layers you can togglebetween: system and user-defined.You can always reset user-defineddefault layers to meet your currentneeds.

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Creating a newglobeWhen you start ArcGlobe,you’ll see image data of theearth drawn on a globe. A globeis the sphere in the displaywindow, or globe view, thatholds your data. You’ll prob-ably want to add more data tothe globe. You can add data assurfaces, images, or floatinglayers. Once you add data to aglobe, you can change the waythe data is rendered by modify-ing a layer’s properties. You canalso change properties thataffect the whole globe, includ-ing background color options,globe illumination, and thevertical exaggeration of theglobe. See ‘The ArcGlobe tableof contents and layer types’ tolearn how to add data tospecific layer types.

Adding data in ArcGlobe

1. Click the Add Data button onthe ArcGlobe standardtoolbar.

2. Navigate to the folder thatcontains the data you want toadd.

3. Click the layer you want toadd.

4. Click Add.

By default, ArcGlobe addsdata as draped layers, exceptfor features with z-values,which are added as floatinglayers.

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Adding data fromArcMap or ArcScene

1. Right-click the layer in theArcMap or ArcScene table ofcontents and click Copy.

2. Click the ArcGlobe window tomake it active, right-clickGlobe layers, then clickPaste Layer(s).

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The ArcGlobedocumentThe Globe document lets yousave all the work you put into aglobe. A Globe document savesinformation about paths to yourdata and the settings you haveindicated in the globe’sproperties and layers so thenext time you open a savedGlobe document, it will appearjust as it did when you saved it.ArcGlobe documents have a.3dd extension.

Saving an ArcGlobedocument


2. Navigate to the locationwhere you’d like to save anArcGlobe document.

3. Type a name for yourdocument.

4. Click Save.

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The ArcGlobetable of contentsand layer typesThe table of contents inArcGlobe differs slightly fromother ArcGIS applications inthat it has three ways ofdisplaying layers: the Displayand Source pages, which arethe same as ArcMap andArcScene; and a third page thatcategorizes layers by their type:elevation, draped, or floating.

Elevation layers give terrain toa globe surface, draped layersare draped on the globesurface, and floating layers useoffsets to display above orbelow the globe surface.

The globe surface is thesurface of the globe on whichdraped layers are drawn. Aglobe terrain is one or moreelevation layers representingone logical surface. Use rasterswith elevation data to definethe globe terrain, adding layersof higher resolution to theelevation layer category toincrease the detail of the globeterrain. Then drape rasterimages or feature classes onthe globe terrain by addinglayers to the draped layerscategory. Finally, add featureclasses or rasters to thefloating layer category and use

Adding elevation data

1. Right-click Globe layers,point to Add Data, and clickAdd elevation data.

2. Navigate to the folder thatcontains the elevation rasteryou want to add.


4. Click Add.

The raster is added as anelevation source for theglobal elevation layer.

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Adding draped data

1. Right-click Globe layers,point to Add Data, and clickAdd draped data.



4. Click Add.

The layer is added as a layerdraped on the globe surface.

offsets or independent surfacesto create layers that floatindependent of the globesurface.

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Adding floating layers

1. Right-click Globe layers,point to Add Data, and clickAdd floating data.



4. Click Add.

The layer is added as a layerthat floats independent of theglobe surface.

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Why doesn’t the layer Iadded float?After you add the layer, you’ll needto define more properties toindicate how you want it to float.

Tip

Can I float an elevationlayer?No. When you define an elevationlayer, it always becomes part of theglobal surface. If you want to floata layer on a surface independent ofthe globe surface, add that layer asa floating layer and use theelevation settings to browse to thesurface you want to use.

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Layer drawingorderThe order of draped layerslisted in the Type page of thetable of contents determineshow the layers are drawn on theglobe. Within the drapedcategory, the layers listed at thetop will draw over those listedbelow them, and so on downthe list. ArcGlobe looks atproperties of a layer, such asraster resolution, to make aninitial assumption aboutdrawing priorities of layers. Youcan also move draped layers inthe Type page of the table ofcontents to adjust their drawingorder on the globe.

Moving a layer to changeits drawing order on theglobe surface

Only layers that are drapedon the globe can have theirdrawing order defined.

1. In the Type page of the tableof contents, click the drapedlayer whose drawing orderyou want to change.

2. Drag the layer to the positionin the table of contents whereyou want it to be drawn.

A black line appears toindicate where the layer willbe dropped.

3. Release the mouse pointer todrop the layer in its newposition.

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Navigating inArcGlobeYou view a globe in a globeviewer. The 3D View tools allowyou to navigate your data in3D. Some of these tools aresimilar to those in ArcMap andArcScene. Other tools arespecialized for the differentnavigation modes used inArcGlobe. The Navigate andFly tools have two modes inArcGlobe: global and surface.Global mode allows you tonavigate without the sense ofgravitational influence; surfacemode gives you a sense of upand down as dictated bygravity. In both modes, clickingthe left and right buttons anddragging up, down, left, or rightlets you rotate the view, zoomin, and zoom out.

Navigating in globalmode


The Navigate tool is in spacemode by default; this isindicated by the Space Modeicon .

The Navigate tool allows youto rotate the globe and zoomin and out.

2. Click the globe and drag tothe right.

When you click the globe anddrag to the right, you rotatethe data counterclockwisearound the north–south axis.

3. Right-click the globe anddrag down.

When you right-click theglobe and drag down, youzoom in to the globe.

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Navigating in surfacemode

Surface mode is best usedwhen navigating near the globesurface.

1. Click the Center on Targetbutton on the 3D Viewtoolbar.

2. Click the location on theglobe surface where youwant to set your target andcenter the view.

The point you clicked iscentered in the view.


The Navigate tool is now insurface mode, as indicatedby the Surface Mode icon.

In this mode, the Navigatetool allows you to rotatearound the surface target,zoom in and out, and pan.The surface is always towardthe bottom of the viewer tosimulate the effect of gravity.

4. Click the globe and drag tothe right.

When you click the globe anddrag to the right, you rotatethe data counterclockwisearound a vertical axisthrough the target.

Tip

Shortcut for centering atargetYou can set the target when innavigation mode by pressing Ctrland clicking the mouse pointer atthe location you want to becentered.

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Switching betweensurface and global mode

1. Click the Navigation Modebutton.

If you click it again, the modewill toggle back.

When the Navigation Modebutton is clicked on, thenavigation is set to globalmode; otherwise, thenavigation is set to surfacemode.

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Keyboard shortcuts forswitching the navigationmodeTo switch from global to surfacemode, press Ctrl and click themouse pointer (you’ll center on thetarget where you clicked). Toswitch from surface to globalmode, press Ctrl + Alt and click themouse pointer.


Centering

1. Click the Center on Targettool.

2. Click the location you want tooccupy the center of theglobe view.

The point you clicked ismoved to the center of theview.

Using the cameratarget to simplifynavigationYou can manipulate the cameratarget to ease navigation toareas you want to explore. Forexample, when you zoom in toyour data, you always zoom toyour target. Changing thelocation of the target defineswhere you zoom in to your data.For more information about thevirtual camera, see ‘The camera,the observer, and the target’ inChapter 4 ‘Managing 3DData’of this book.

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Tip

Zoom to target shortcutYou can zoom to a target when innavigation mode by pressing Ctrland right-clicking the mouse.

Zooming to a target

1. Click the Zoom to Target tool.

2. Click the location on theglobe where you want tozoom.

The point you click becomesthe center of your view asyou zoom toward it.

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Zooming to alayer’s extentA useful way of examining astudy area is to zoom to alayer’s extent in the display.This method is a quick and easyway of zooming in to the area ofconcern, particularly if youhave many study areas in theglobe.

Tip

Graceful transitionsYou can set an option to animatecamera movements when zoomingin and out of the globe. Setting thisoption will animate the camera in asmooth fashion along the way toyour destination. To set this option,go to the Application page of theOptions dialog box and checkAnimate viewer when using toolsand commands. See ‘ArcGlobeapplication-level options’ in thischapter.

Tip

Zooming to more than onelayer’s extentYou can zoom to the extent of morethan one layer at a time by selectingmultiple layers in the table ofcontents and right-clicking to zoomto their combined extent.

Zooming to a layer

1. Right-click the layer to whichyou want to zoom and clickZoom To Layer.

The display zooms to theextent of the layer.

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Using the WalktoolSometimes the best way tonavigate your data is to flyabove it or to walk through it atsurface level. Use the Fly toolto gain unique perspectivesfrom the air. See ‘Navigatingthrough a scene using the Flytool’ in Chapter 7 ‘3D Visualiza-tion’ of this book for moreinformation about how to usethe Fly tool. Use the Walk toolto explore your data from theground. Similar to the Fly tool,the Walk tool allows you tonavigate in walk mode, walkingin any direction and movingforward or backward at differentspeeds.

Tip

Fine-tuning the walk speedIn between mouse clicks, press thekeyboard arrow left or right toincrease or decrease speed,respectively.

Using the Walk tool tonavigate

1. Click the Walk button.

The cursor changes toindicate walk mode is active.

2. Click once in the center ofthe view.

The tool enters the sus-pended state. You can movethe mouse pointer to look inall directions, but there is noforward or backward move-ment.

3. Press arrow up or down onthe keyboard to increase ordecrease the elevation,respectively.

4. Click the mouse to moveforward. Right-click to movein reverse. Successive clicksin either direction increasethe speed.

Speed is indicated in thestatus window.

5. Click the opposite mousebutton to slow down incre-mentally and stop.

Press Esc to immediatelystop movement in eitherdirection.

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Globe layerpropertiesTo display data, ArcGlobe usessome properties that aren’tavailable in other ArcGISapplications. These propertiesbecome available when you adda layer to ArcGlobe and allowyou to set various options todetermine how a layer getsdisplayed, how it gets elevationinformation, and how it’scached.

Tip

Another way to bring up theLayer Properties dialogboxDouble-click the layer’s name in thetable of contents.

Opening a layer’sproperties dialog box

1. Right-click the layer in thetable of contents and clickProperties.

The Layer Properties dialogbox is presented. The LayerProperties dialog boxprovides access to a layer’s2D and 3D properties.

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Setting thevisibility range ofa layerSometimes you’ll only want alayer to appear in the displaywhen you’re zoomed to aparticular distance. Usingvisible distance ranges, you canset at what point a layerbecomes visible in the display.Use visible distance ranges tomake layers appear in thedisplay at defined distancesfrom the globe. For example, setthe distance ranges for locallayers with small extents sothey’re visible only when youzoom in to their proximity.Visible distance range units arethose defined as globe displayunits in the General page of theGlobe Properties dialog box.

Setting the visibledistance range of a layer

1. Right-click the layer in thetable of contents whosevisible distance range youwant to set and click Proper-ties.

2. Click the Globe General tab.

3. Check Don’t show layerwhen zoomed.

4. Type the distance in the outbeyond text box at which youwant the layer to becomeinvisible when you zoom out.

5. Type the distance in the inbeyond text box at which youwant the layer to becomeinvisible when you zoom in.

6. Optionally, click Checkvisibility based on each tiledistance to enable distancevisibility for discrete parts ofthe layer.

7. Click OK.

The layer will be visiblebetween the two thresholds.

You can also set the visibilityrange from the context menu,using the current distances ofthe display. See the tip on thispage.

Tip

Setting a layer’s visibilityrange from the contextmenuYou can also set a layer’s visibilityrange by using the currentdistances in the display. In alayer’s context menu, use the SetMaximum Distance and SetMinimum Distance commands inthe Visible Distance Range contextmenu to capture distances used inthe display.

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Reclassifying alayerYou can change how a layer iscategorized in ArcGlobe—as anelevation, draped, or floatinglayer—by using context menucommands. After you categorizea layer, you’ll be able to usedifferent options that becomeavailable for a layer in thatcategory.

Elevation layers provide asource of base heights for theglobe surface. Add rasters withheight source information aselevation layers to make a globeterrain.

Tip

Adding a layer as anelevation sourceIf you know you want to add asingle band raster as an elevationsource, you can add it directly tothe Elevation layers category byright-clicking Globe layers,pointing to Add Data, and clickingAdd elevation data.

Redefining data as anelevation layer

1. Right-click the layer you wantto reclassify in the table ofcontents, point to Redefinelayer, and click Redefinelayer as elevation.

Note: This option is onlyavailable for single bandrasters.

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Draped layersDraped layers are layers thatuse the base heights of theglobe surface as elevationsources. Drape a layer to showit on the globe surface. Forexample, you might drape anaerial photo and its associatedfeatures on a mountain top.

Rasters and 2D features areadded as draped layers bydefault.

Tip

Adding a layer as a drapedlayerIf you know you want to add adraped layer on the globe surface,you can add it directly into thedraped layers category by right-clicking Globe layers, pointing toAdd Data, and clicking Add drapeddata.

Redefining data as adraped layer

1. Right-click the layer you wantto reclassify in the table ofcontents, point to Redefinelayer, and click Redefinelayer as draped.

The layer is draped on theglobe surface.

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What is a floatinglayer?A floating layer floats indepen-dently of the globe surface. Youcan use offsets or independentsurfaces to define where in 3Dspace the layer is drawn, aboveor below the globe surface. Usefloating layers to show utilities,aircraft, or clouds.

Tip

Adding a layer as a floatinglayerIf you know you want to add alayer as a floating layer indepen-dent of the globe surface, you canadd it directly into the floatinglayers category by right-clickingGlobe layers, pointing to Add Data,and clicking Add floating data.

Tip

How can a surface not bepart of the globe elevation?An example of a surface that isindependent of the globe surface isan analytical surface, such as araster showing ozone concentra-tions. When you define an elevationlayer, it always becomes part of theglobe surface. If you want to float alayer on a surface independent ofthe globe surface, add or redefinethe layer as a floating layer and usethe elevation settings to browse tothe surface you want to use as asource of base heights.

Defining a layer as afloating layer

1. Right-click the layer you wantto redefine, point to Redefinelayer, and click Redefinelayer as floating.

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Redefining a layer’scategory in the table ofcontents

1. Click the layer in the table ofcontents whose category youwant to change.

2. Drag the layer to the newcategory.

A black line appears wherethe layer will be dropped.

3. Release the mouse pointerto drop the layer in its newcategory.

The layer is reclassified asthe type you indicated. Youmay have to set someproperties for the layer todisplay it properly.

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Tip

Redefining a layer usingthe context menuYou can also redefine a layer’scategory by right-clicking the layerin the table of contents and clickingRedefine layer.


Layer cachepropertiesYou can set options that controlhow individual layer caches aretreated by ArcGlobe. Theseoptions dictate what happens toa layer’s cache when disk spaceis needed in the globe cache orafter you exit ArcGlobe.

Setting cache removal optionslets you manage the size of theArcGlobe cache.

To save a cached layer in theArcGlobe cache, you’ll have tosave the layer or save the Globedocument that contains thelayer.

If you need to restrict the size ofthe globe cache, you canspecify that a layer’s cache willbe deleted either when storagespace is needed or when youexit ArcGlobe.

Setting the cacheremoval option to deletea layer’s cache when diskspace is needed

1. Right-click the layer in thetable of contents whosecache properties you want tochange and click Properties.

2. Check the check box underCache removal options forStorage space is needed.

When ArcGlobe needs tomanage the size of the globecache, it may delete thislayer’s cache.

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Setting the cacheremoval option to removea layer’s cache whenremoving the layer fromthe table of contents orwhen exiting ArcGlobe

1. Right-click the layer in thetable of contents whosecache properties you want tochange and click Properties.

2. Check the check box underCache removal options forExiting the application orremoving the layer.

When the layer is removedfrom the table of contents oryou exit ArcGlobe, the layer’scache will be cleared.

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Globe displaylayer propertiesGlobe display properties dictatehow a layer will appear in theglobe view. Use globe displayproperties to determine araster’s or rasterized feature’stexturing mode or drawingpriority, whether a feature israsterized, or how 3D symbolsin a feature class are scaled.

A raster’s texturing modedetermines how it will look inthe display. In general, imageswill look better with a smoothtexture mode. Use the NearestNeighbor texture mode forlayers that should preservedistinct boundaries, such as arasterized polygon feature classwith distinct polygonal bound-aries.

Changing the texturingmode of an image layer

1. Right-click the image in thetable of contents and clickProperties.

2. Click Globe Display.

3. Click the Image Texturingmode dropdown arrow andselect the texturing mode youwant to use.

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RasterizingfeaturesRasterizing features inArcGlobe allows you tomaintain any cartographicsymbology that you may havesaved in ArcMap. It’s also aneffective way to drape featureson the globe surface. Bydefault, 2D points, lines, andpolygons are added toArcGlobe as rasterizedfeatures. 3D points and linesare added as vectors.

Setting a layer to draw asvectors

1. In the table of contents,double-click the layer.


3. Uncheck Rasterize featurelayer.

4. Click OK.

The features will be drawn asvectors.

Tip

Rasterized polygonsLines and points can be displayedas vectors or rasterized. Polygonsare always rasterized.

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Why are some, but not all,features rasterized bydefault?By default, polygons, 2D lines, and2D points are rasterized. 3D linesand 3D points are not rasterized bydefault.


FeaturepropertiesTo display features, a scaleneeds to be set. ArcGlobemakes an estimate about whatthe scale should be, but youmay need to alter the scale forthe layer on the Featureproperties dialog box.

When you set a scale for alayer, you indicate at whatdistance, or scale, the featuresin that layer become visible.

Setting the featureproperties of features in alayer

1. In the table of contents,double-click the layer whosefeature properties you wantto set.

2. Click Globe General.

3. Click the Feature Propertiesbutton.

4. Move the Scale slider toselect an appropriate scalerange to display the featuresin the layer.

Use the images, level,approximate scale, anddistance information to helpyou decide which scale isappropriate for the layer.

5. Click OK.

6. On the Layer Propertiesdialog box, click OK.

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Scaling 3DsymbolsWhen you symbolize points inArcGlobe using 3D symbols,you may want to scale thesymbols so they maintain theirsize in relation to the globe andthe rest of its layers when youzoom in and out. You can turnon the option to scale 3Dsymbols in the Globe Displaypage of the Layer Propertiesdialog box.

Tip

What kinds of layers canbe scaled?Only point feature layers contain-ing 3D symbology can be scaled.

Scaling the size of 3Dsymbols in a layer

1. Double-click the 3D Symbolslayer in the table of contents.


3. Check the Scale 3D symbolswith distance check box.

4. Click OK.

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See-throughpositionFloating layers can be given adrawing order based on theirposition relative to the globesurface when usingtransparencies. For example, ifyou have a subterranean layerbelow the globe surface and anaerial layer above the globesurface, and you’d like to settransparencies for the layers soyou can see them all, you canuse see-through positions for thefloating layers. Picture the globesurface with a value of zero. Thesubterranean layer would receivea value of -1, and the aerial layerwould receive a value of +1. Ifyou then added a subterraneanlayer with a lower elevation, itwould receive a see-throughvalue of -2, and an aerial layerwith a higher elevation wouldreceive a value of +2.

Setting the see-throughvalue for a floating layer

1. In the table of contents, right-click the layer whose see-through value you want to setand click Properties.


3. Click the See-throughposition dropdown arrow andselect a value.

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Globe propertiesGlobe properties, includingvertical exaggeration, back-ground characteristics, andillumination, can be changed tosuit your particular needs. Thiscan be done to enhance realismor accentuate specific aspectsof your globe. Changes made inthe Globe Properties dialog boxapply to the current document.

Use vertical exaggeration toemphasize the topography ofthe globe surface or floatinglayers.

Changing the verticalexaggeration of the globesurface

1. In the table of contents, right-click Globe layers and clickGlobe Properties.

2. Click General.

3. In the Vertical ExaggerationOf globe surface dropdowncombo box, choose a value.

Alternately, you can type avalue.

4. Click OK.

The surface of the globe isexaggerated by the valueyou indicated.

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Changing the verticalexaggeration of thefloating layers


2. Click General.

3. In the Vertical ExaggerationOf floating layers dropdowncombo box, choose a value.

Alternately, you can type avalue.

4. Click OK.

Floating layers are exagger-ated by the value youindicated.

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Selecting and settingbimodal backgroundcolor options

1. In the table of contents,double-click Globe layers.

2. Click Background.

3. Click the Mode dropdownarrow and click Transitionalcolor.

4. Click the Space colordropdown arrow, and select aspace color.

5. Optionally, type an upper andlower limit for the transitionzone.

The colors will begin to fadeinto each other based on thethresholds you define here.

6. Click the Sky color dropdownarrow, and select a sky color.

7. Click OK.

BackgroundoptionsYou can choose from a varietyof options to customize thebackground of your globe. Bydefault, the background colorchanges depending on thecamera observer location. Youcan change whether thebackground is a single color orthe default transition betweentwo colors and how thetransitional colors changebased on camera observerelevation.

When using transitional colormode, the space color is thebackground of the globe viewwhen viewing the globe fromhigh altitudes. The sky color isthe background when you’reviewing closer to the globesurface.

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Selecting single colorbackgrounds

1. Right-click Globe layers andclick Globe Properties.

2. Click Background.

3. Click the Mode dropdownarrow and click Single color.

4. Click the Sky color dropdownarrow, and select a color forthe background.

5. Click OK.

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IlluminationoptionsYou can choose to illuminatethe globe based on the sun’sposition or not illuminate it atall. You can define where thesun’s rays strike the globesurface most directly geo-graphically or based on time. Inaddition, you can modify theway the unlit side of the globeis illuminated.

Turning on illuminationbased on the sun’sposition


2. Click Sun Position.

3. Check Enable sun lighting.

4. Click OK.

The globe is illuminatedbased on the position of thesun on the dialog box.

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Changing theillumination based ongeography




4. Click and drag the yellowsun symbol to the place onthe map that you want thesun to shine on.

5. Alternately, type in thelatitude and longitude valuesof the location you’d like thesun to shine.

6. Optionally, move the slider toindicate how bright you wantthe unlit side of the globe tobe.

7. Click OK.

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Changing theillumination based ontime




4. Click Set sun position basedon time, and type in values ofthe time you want the sunposition to be.

Optionally, click Now for real-time sun lighting.

5. Optionally, move the slider toindicate how bright you wantthe unlit side of the globe tobe.

6. Click OK.

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ArcGlobeapplication-leveloptionsYou can set options that controlthe way ArcGlobe behavesevery time it starts. Theseoptions stay the same unlessyou change them. Application-level options include settingsthat affect the way ArcGlobebehaves, how thegeoprocessing frameworkbehaves, table behavior, andhow rasters are handled. Next,you’ll see how to change someoptions that control the wayArcGlobe behaves.

You can control the way thecamera behaves when it movesbetween locations. You can setoptions that move the camerasmoothly between the locationsyou zoom to.

Animating cameramovements whentransitioning betweenviews


2. Click General.

3. Check the Animate viewerwhen using tools andcommands check box.

Optionally, move the Speedslider to indicate how quicklythe transitions will occur.

4. Click OK.

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Setting the default viewfor full extent


2. Click General.

3. In the Full View ObserverPosition window, click thelocation of the globe youwant to see when you clickFull Extent.

A red X appears at thelocation you clicked, indicat-ing the part of the globe thatwill be shown as default inthe full extent position.

Optionally, type in decimaldegree values in the Latitudeand Longitude text boxes.

4. Click OK.

Setting thedefault view atfull extentYou can set the location yousee on the globe when youzoom to full extent. This way,when you zoom to the fullextent of the globe, you’ll seethe part of the world you’reinterested in.

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Application-levelcache optionsYou can control the wayArcGlobe manages caches,including the size of the memorycache, the location or size of thedisk cache, or the default tile sizeof feature caches.

The size of the memory cachedetermines how much of yourcomputer’s physical memoryArcGlobe will use. The first timeyou start ArcGlobe, it willestimate how much memory touse based on how much isavailable on your computer. Youcan manually change theallocation.

Changing how muchmemory ArcGlobe uses


2. Click Cache.

3. In the Size of memory cachetext box, type the amount ofmemory you want ArcGlobeto use.

4. Click OK.

If you indicate a value higherthan is available on yourcomputer, ArcGlobe willbegin to use virtual memory.

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Disk cachesArcGlobe creates files on yourcomputer’s disk that help itefficiently navigate and displaydata. These disk caches may betemporary or permanent, as youchoose. See ‘What is cachingand how do I use it?’ later inthis chapter for more informa-tion about layer caching andhow it gets stored on disk.

Layer caches are stored in theArcGlobe disk cache. Bydefault, the globe’s cache iscreated in your user profilelocation, for example,C:\Documents andSettings\<user>\LocalSettings\Temp\GlobeCache.You can change the location ofthe globe cache and determineits maximum size.

Setting the globe cachelocation


2. Click Cache.

3. Check Use a disk cache toimprove visualization speed.

4. In the Cache path text box,type the path to the locationthat you want your cache.

Optionally, browse to thelocation.

5. Optionally, in the Maximumsize text box, type themaximum size that you wantthe globe cache to be ondisk.

The maximum size of theglobe cache applies only totemporary caches (thosedeleted on exit). A globecache that contains perma-nent layer caches mayexceed the indicated maxi-mum cache size.

6. Click OK.

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Level of detailYou can control how much of animage or elevation raster’squality, or level of detail, is usedwhen displaying it in ArcGlobe.When changing the level ofdetail setting for rasters, beaware that the higher the level ofdetail, the more compromised theperformance.

Changing the level ofdetail displayed by imageand elevation rasters


2. Click Level of Detail.

3. Move the Image slider to thedesired level of detail.

4. Move the Elevation slider tothe desired level of detail.

5. Optionally, click RestoreDefaults to return to theoriginal settings.

6. Click OK.

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CompressionoptionsArcGlobe uses compressiontechniques to more efficientlydisplay rasters. These optionsare on by default to increase theperformance of images inArcGlobe, but you can chooseto turn off the different com-pression types.

Radiometric compressionreduces the number of bits usedto display the colors of animage. Using compressionsacrifices some image quality atthe benefit of performance byreducing the cache size.

Turning off radiometriccompression

1. Click Tools and clickOptions.

2. Click Compression.

3. Uncheck Use radiometriccompression of colors to16 bits.

4. Click OK.

Note that ArcGlobe usesradiometric compressionby default to more effi-ciently display images.Turning off this featuremay result in poor perfor-mance.

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Lossy spatialcompressionLossy spatial compressionreduces cache storage space byspatially averaging the distribu-tion of colors in an image. Thisresults in increased perfor-mance.

Turning off lossy spatialcompression



3. Uncheck Use lossy spatialcompression.

4. Click OK.

Note that ArcGlobe useslossy spatial compression bydefault to more efficientlydisplay images. Turning offthis feature may result in poorperformance.

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ElevationcompressionElevation compression reducesthe number of bits used todisplay the elevation range of araster. This decreases the cachesize and increases performance.

Turning off elevationcompression



3. Uncheck Compress elevationrange to 16 bits (1 m. verticalaccuracy).

4. Click OK.

Note that ArcGlobe useselevation compression bydefault to more efficientlydisplay elevation rasters.Turning off this feature mayresult in poor performance.

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Table of contentsoptionsThe ArcGlobe table of contentshas three different pages: theDisplay, the Type, and theSource pages. The Displaypage shows a simple list andlegend of the layers in yourdocument. The Type pageshows the layers in yourdocument categorized by theirlayer classification. The Sourcepage shows the paths to thelayers in your document.

Using application-level options,you can choose the ordering ofthese pages, indicating whichyou’d like to see by default.

See Also

See ‘The ArcGlobe table of contentsand layer types’ section earlier inthis chapter for more informationabout the table of contents andlayer classification.

Setting table of contentsdisplay preferences


2. Click Table Of Contents.

3 Optionally, check the boxesnext to the layers you want tosee in the table of contents.

Uncheck them if you don’twant to see them.

Optionally, set the displayorder of the pages.

4. Click a layer to select it.

5. Click the Up or Down arrowbuttons to change the orderin which the pages aredisplayed.

6. Click OK.

The setting you choose willbe the default every time youstart ArcGlobe.

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What is cachingand how do Iuse it?When you add a layer toArcGlobe, it creates a tempo-rary file, or cache, that helpsyou display and navigate yourdata efficiently. A cache storesthe data and information thatallow ArcGlobe to bettermanage your environment bycontrolling levels of detail.Caches may be on-demand, orpartial, containing somedetails of the layer, or full,containing all the details thelayer has to offer. As younavigate your layers inArcGlobe, the parts of the datayou zoom to are cached on-demand to disk. Revisitingthese areas subsequent timeswill be faster because they arealready cached. In addition,it’s possible to generate apartial or full cache as a batchprocess. This is beneficial ifyou need ArcGlobe to displayany potential area at a speci-fied level of detail (partialcache) as fast as possible orany potential area at thehighest level of detail as fastas possible—for example,when giving demonstrationsto an audience.

Most of the time, it’s better tocache part of your data, u

Saving a layer’s cache

1. In the table of contents, right-click the layer whose cacheyou want to save and clickSave As Layer File.

2. Navigate to the locationwhere you want to save thelayer.

3. Type the name you want tosave the layer as.

4. Click Save.

The layer’s cache is pre-served through reference bythe layer file. Saving thecache preserves optimizationof areas you’ve visited.

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building an on-demand diskcache as you navigate andsaving disk space. By doingthis, the places you visit (andmay visit again) will becomepart of the cache, but placesyou never visit don’t becomepart of the cache. A conse-quence of an on-demand cacheis a slightly increased time tobuild the cache and bring thehighest detail into the viewwhen visiting new places. Analternative to the on-demandcache is to build a cache at aspecified level of detail. Thisprocess makes a cache of theentire layer at the specifiedlevel of detail. For people whowant the highest resolution ofthe data available in theshortest amount of navigationtime for any potential region ofthe data, creating a full cache ofthe data may be the bestalternative. The possibility oflong processing times andincreased disk space require-ments make full caching asecondary option to on-demandcaching. Consider your needsby evaluating whether you willonly need quick access to thehighest detailed data in arelatively smaller number ofareas, whether you can workwith all areas at a specified levelof detail, or whether you needquick access to all areas at theirhighest level of detail.

Generating a cache

1. In the table of contents, right-click the layer you want tocache and click GenerateData Cache.

2. Drag the From LOD slider tothe minimum scale at whichyou want to cache the data.

3. Drag the To LOD slider to themaximum scale at which youwant to cache the layer.

Setting the levels of detail atwhich you want to create acache makes a partial cacheof the data. The remaininglevels will be cached on-demand.

To create a full cache, set theFrom LOD slider to thesmallest scale, or Near, andset the To LOD slider to thelargest scale, or Far.

4. Click OK.

The caching process begins.Depending on the size of thedata, the process may takesome time to complete.

Click Cancel to terminate thecaching process.

Don’t forget to save the dataas a layer file or to save thedocument to preserve thecache.

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A variety of cache manage-ment options are available,allowing you to delete cacheson layer removal or exit, deletecaches as space is needed,and set the size and location ofthe ArcGlobe cache folder.

Tip

Another way to save acacheWhen you save a globe document,the state of caches for layers in thetable of contents is saved.

353

123D featureA representation of a three-dimensional, real-world object in a map or scene, with elevation values(z-values) stored within the feature’s geometry. Besides geometry, the feature may have attributesstored in a feature table.

3D graphicA representation of a three-dimensional, real-world object in a map or scene, with elevation values(z-values) stored within the feature’s geometry. Unlike 3D features, the graphic does not haveattributes.

3D modelA paradigm used to portray an object in three dimensions.

3D shapeA point, line, or polygon which stores z-coordinates, or elevation, in addition to x,y coordinates aspart of its geometry. A point has one z-coordinate; lines and polygons have one z-coordinate foreach vertex in the shape.

3D styleIn ArcScene and ArcGlobe, a library containing 3D symbols.

3D symbolA symbol that has properties which allow it to be rendered in three dimensions.

altitude1. The height, z-value, or vertical elevation of a point above or below a given reference datum (such

as sea level) or surface (such as land).

2. The height above the horizon, measured in degrees, from which a light source illuminates asurface; used when calculating a hillshade or for controlling the position of the light source in ascene for on-the-fly shading.

animationIn ArcScene and ArcGlobe, a collection of tracks in a document that defines dynamic propertychanges related to associated objects.

Glossary


Animation ManagerIn 3D Analyst, the interface in which the properties of keyframesand tracks can be edited, and an animation can be timed andpreviewed.

area1. A fundamental spatial unit consisting of a closed, two-

dimensional shape defined by its boundary. Its extent isusually defined in terms of an external polygon or by acontiguous set of grid cells.

2. A mathematical calculation of the size of a two-dimensionalgeographic feature, measured in square units.

aspectThe compass direction in which a topographic slope faces,usually expressed in terms of degrees from the north. Aspect canbe generated from continuous elevation surfaces. The aspectrecorded for a TIN face is the steepest downslope direction of theface. The aspect of a cell in a raster is the steepest downslopedirection of a plane defined by the cell and its eight surroundingneighbors.

attribute1. Information about a geographic feature in a GIS, generally

stored in a table and linked to the feature by a unique identifier.For example, attributes of a river might include its name, length,and average depth.

2. In raster datasets, information associated with each uniquevalue of raster cells.

3. Cartographic information that specifies how features aredisplayed and labeled on a map; the cartographic attributes ofa river might include line thickness, line length, color, and font.

autocorrelationGenerically, a statistical measure which describes the extent towhich one property changes as another changes. In GIS it is usedto refer to a statistical measure which describes the extent towhich the value of an attribute at geographically referencedpoints changes as a function of the distance and orientationbetween them.

azimuthA compass direction. In 3D Analyst and Spatial Analyst, thedirection from which a light source illuminates a surface is calledthe azimuth.

backgroundIn ArcScene or ArcGlobe, the backdrop of the view. The color ofthe background can be set to suggest sky, empty space, or anycolor that improves visualization.

base heightThe height at which a surface, raster, or feature is drawn in ascene. Base height for features and rasters can be set from asurface such as a digital elevation model (DEM) or using aconstant value or expression. Features with z-values stored intheir geometry can have their base height set using the z-values.Setting the base heights from a surface is also called draping.

bin1. In a variogram map, each cell that groups lags with similar

distance and direction. Bins are commonly formed by dividingthe sample area into a grid of cells or sectors, and are used tocalculate the empirical semivariogram for kriging.

2. In a histogram, user-defined size classes for a variable.

GLOSSARY 355

cameraIn 3D Analyst, an object that defines the perspective of a scene’sdisplay.

Catalog treeIn ArcCatalog, a hierarchical view of folder connections thatprovide access to GIS data stored on local disks or shared on anetwork, and allows users to manage connections to databasesand GIS servers.

categorical rasterA raster that represents the world with a set of values that havebeen aggregated into classes. For example, a satellite image thathas been reclassified to extract a number of landcover types is acategorical raster. Categorical rasters represent an area, but thevalues do not form a continuous surface.

continuous rasterA raster that represents the world with a set of values that varycontinuously to form a surface. For example, a raster digitalelevation model and an interpolated chemical concentrationsurface are continuous rasters.

contour lineA line drawn on a map that connects points of equal elevationabove a datum, usually a mean sea level.

cullIn ArcScene and ArcGlobe, to selectively choose not to draw oneside of an areal feature.

disk cacheIn ArcGlobe, the folder on a computer’s disk drive whereArcGlobe stores layer cache files.

draped layerA layer in ArcGlobe that has been categorized to be draped ontop of the globe surface.

drapingSetting the base height for features or a surface using a surface.For example, an aerial photograph might be draped over a digitalelevation model (DEM) to create a realistic terrain visualization.

drawing priorityThe order in which layers that occupy the same x,y,z positions aredrawn in a scene. For example, if a road feature layer and anorthophoto are draped over the same terrain model, the roads andraster may appear patchy or broken up where they coincide. Thedrawing priority for the raster can be reduced so it will appearbelow the features. The drawing priority can only be changed forpolygon features and surfaces.

edgeA line between two nodes, points, or junctions that forms theboundary of one or more faces of a spatial entity. In an image,edges separate areas of different tones or colors. In topology, anedge defines lines or polygon boundaries; multiple features inone or more feature classes may share edges. In a TIN, the lineconnecting nodes.

elevation layerA layer in ArcGlobe that has been categorized to help define thegeometry of the globe surface.

extrusionProjecting features in a two-dimensional data layer into three-dimensional space: points become vertical lines, lines becomewalls, and polygons become solid blocks. Uses of extrusioninclude showing the depth of well point features or the height ofbuilding footprint polygons.


faceA region bounded by a closed sequence of edges. Faces arecontiguous and do not overlap. On a TIN surface, each face isdefined by three edges and three nodes, and is adjacent to one ofthree faces of the surface. TIN faces store aspect and slopeinformation, and may have tag values.

floating layerA layer in ArcGlobe that has been categorized to floatindependently above or below the globe surface.

full cacheIn ArcGlobe, a layer cache saved on disk that contains completelevels of details for the entire layer.

geospecific modelA model that is based on a real-world feature. For example, ageospecific model for the White House would look exactly likethe White House and be used to represent the White House on amap of Washington, D.C.

See also geotypical model.

geotypical modelA symbolic representation for a class of objects, such asgovernment buildings. For example, on a map of the UnitedStates, a white building with a dome on top could be used as ageotypical model for all state capitols.

See also geospecific.

global modeA navigation mode in ArcGlobe during which the camera target isalways at the center of the globe.

globeIn ArcGlobe, the sphere in a globe view on which data isdepicted.

globe documentA disk-based representation of the globe view or views containedin ArcGlobe. Globe documents have a .3dd extension.

globe propertiesIn ArcGlobe, properties that can be set for a globe document.These include vertical exaggeration, background color, or sunposition.

globe terrainA globe surface with base heights supplied from an elevationlayer.

globe viewIn ArcGlobe, the display window in which a globe can be viewed.

hillshading1. Shadows drawn on a map to simulate the effect of the sun’s

rays over the land.

2. On a raster, a simulated shadow effect achieved by assigningan illumination value from 0 to 255 to each cell according to aspecified azimuth and altitude for the sun. Hillshading createsa three-dimensional effect.

IDWSee inverse distance weighted (IDW).

imageA raster-based representation or description of a scene, typicallyproduced by an optical or electronic device such as a camera or ascanning radiometer. Common examples include remotely sensed

GLOSSARY 357

data (for example, satellite data), scanned data, and photographs.An image is stored as a raster dataset of binary or integer valuesthat represent the intensity of reflected light, heat, sound, or anyother range of values on the electromagnetic spectrum. An imagemay contain one or more bands.

interpolationThe estimation of surface values at unsampled points based onknown surface values of surrounding points. Interpolation can beused to estimate elevation, rainfall, temperature, chemicaldispersion, or other spatially based phenomena. Interpolation iscommonly a raster operation, but it can also be done in a vectorenvironment using a surface model called a triangulated irregularnetwork (TIN). There are several well-known interpolationtechniques, including inverse distance weighted and kriging.

inverse distance weighted (IDW)An interpolation technique that estimates cell values in a raster orimage with a set of sample points that have been weighted so thatthe farther a point is from the cell being evaluated, the lessimportant it is in calculating the cell’s value.

keyframeIn a 3D Analyst animation, a snapshot of an object’s properties ata certain time.

krigingAn interpolation technique in which the surrounding measuredvalues are weighted to derive a prediction for an unmeasuredlocation. Weights are based on the distance between themeasured points, the prediction locations, and the overall spatialarrangement among the measured points. Kriging is based onregionalized variable theory, which assumes that the spatialvariation in the data being modeled is statistically homogeneousthroughout the surface. That is, the same pattern of variation canbe observed at all locations on the surface.

lagThe line (vector) that separates any two locations. A lag hasdistance (length) and direction (orientation

line of sight1. A line drawn between two points, an origin and a target, in athree-dimensional scene that shows whether the target is visiblefrom the origin and, if it is not visible, where the view isobstructed.

2. In a perspective view, the point and direction from which theviewer looks into the image.

memory cacheIn ArcGlobe, the amount of system memory that the applicationwill use.

natural neighborsAn interpolation method that estimates cell values usingweighted values of the input data points that are their naturalneighbors, determined by creating a triangulation of the inputpoints.

navigateTo interactively change the observer’s or target’s position using atool designed for this purpose, such as the navigate or fly tool.There are three contexts in which a user can navigate: in a sceneof ArcScene, in a preview of ArcCatalog, and in a globe ofArcGlobe.

nodataIn a raster, the absence of a recorded value. While the measure ofa particular attribute in a cell may be zero, a nodata valueindicates that no measurements have been taken for that cell atall.


nodeIn a TIN, one of the three corner points of a triangle, topologicallylinked to all triangles that meet there. Each sample point in a TINbecomes a node in the triangulation which stores elevation z-values and may have tag values.

nuggetA parameter of a covariance or semivariogram model thatrepresents independent error, measurement error, and/ormicroscale variation at spatial scales that are too fine to detect.The nugget effect is seen as a discontinuity at the origin of eitherthe covariance or semivariogram model.

observerIn ArcScene and ArcGlobe, the position of the camera in a scene.

See also camera.

observer offsetIn ArcScene and ArcGlobe, the height of the observer pointabove a surface used in analysis when calculating lines of sightand viewsheds.

See also camera, observer.

offsetA change in or the act of changing the z-value for a surface orfeatures in a scene by a constant amount or by using anexpression. Offsets may be applied to make features draw justabove a surface.

on-demand cacheIn ArcGlobe, a temporary layer cache that is placed on disk andbuilt as areas of the layer are viewed.

orthographic viewIn 3D Analyst, a perspective that allows viewing of data in ascene as a two-dimensional plane seen from above. There is noperspective foreshortening in orthographic view, so scale isconstant across the entire display.

partial cacheIn ArcGlobe, an on-demand cache that contains levels of detailfor areas that have been visited, or a pre-processed cache thathas a specified, incomplete, level of detail range for the entirelayer.

pathIn 3D Analyst and ArcGlobe, a single line feature or graphic that,when imported to an animation track, determines the movement ofa camera or layer.

perspective viewA projection mode in 3D applications that allows viewing from aperspective that can be controlled by navigating the scene orglobe from a specified location.

pre-processed cacheIn ArcGlobe, a cache that is built prior to viewing, using anindependent process accessed from the context menu of a layer.

profile graphA graph of the height of a surface along a specified line.

rangeA parameter of a variogram or semivariogram model thatrepresents a distance beyond which there is little or noautocorrelation among variables.

GLOSSARY 359

rasterA spatial data model that defines space as an array of equallysized cells arranged in rows and columns. Each cell contains anattribute value and location coordinates. Unlike a vectorstructure, which stores coordinates explicitly, raster coordinatesare contained in the ordering of the matrix. Groups of cells thatshare the same value represent geographic features.

rasterized feature layerIn ArcGlobe, a feature class that has been added and rendered asa raster in order to retain its cartographic symbology.

relief shadingSee hillshading.

raster resolution1. The area represented by each cell or pixel in a raster.

2. The smallest spacing between two display elements, expressedas dots per inch, pixels per line, or lines per millimeter.

3. The detail with which a map depicts the location and shape ofgeographic features. The larger the map scale, the higher thepossible resolution. As scale decreases, resolution diminishesand feature boundaries must be smoothed, simplified, or notshown at all; for example, small areas may have to berepresented as points.

sceneIn 3D Analyst, a document containing 3D data that can be viewedin perspective.

semivariogramThe variogram divided by two.

sillA parameter of a variogram or semivariogram model thatrepresents a value that the variogram tends to when distancesbecome very large. At large distances, variables becomeuncorrelated, so the sill of the semivariogram is equal to thevariance of the random variable.

slopeThe incline, or steepness, of a surface. The slope of a TIN face isthe steepest downhill slope of a plane defined by the face. Theslope for a cell in a raster is the steepest downhill slope of a planedefined by the cell and its eight surrounding neighbors. Slopecan be measured in degrees from horizontal (0—90) or percentslope, which is the rise divided by the run, multiplied by 100. Aslope of 45 degrees equals 100 percent slope. As slope angleapproaches vertical (90 degrees), the percent slope approachesinfinity.

splineA mathematical curve used to smoothly represent spatialvariation, either in a line or on a surface. A spline operationinserts vertices to create a curve in a line.

steepest pathA line that follows the steepest downhill direction on a surface.Paths terminate at the surface perimeter or in surface concavitiesor pits.

stretchA display technique that increases the visual contrast betweencells of similar value when applied to raster datasets.


surfaceA geographic phenomenon represented as a set of continuousdata, such as elevation or air temperature over an area, or theboundary between two distinct materials or processes. A clear orsharp break in values of the phenomenon (breaklines) indicates asignificant change in the structure of the phenomenon, such as acliff, not a change of geographic feature. Surfaces can berepresented by models built from regularly or irregularly spacedsample points on the surface, or by contour lines, isolines,bathymetry, or the like.

surface modeA navigation mode in ArcGlobe in which the camera target isalways on the globe surface.

targetIn ArcScene and ArcGlobe, the center point in a scene’s view atwhich the camera is aimed.

target offsetIn ArcScene and ArcGlobe, the height of a target point above asurface used when calculating lines of sight and viewsheds.

TINTriangulated irregular network. A vector data structure used tostore and display surface models. A TIN partitions geographicspace using a set of irregularly spaced data points, each of whichhas an x-, y-, and z-value. These points are connected by edgesinto a set of contiguous, non-overlapping triangles, creating acontinuous surface that represents the terrain.

trackAn ordered collection of like keyframes that, when played as ananimation, shows a dynamic transition between them.

triangleTriangles form the faces on a TIN surface. Each triangle on a TINsurface is defined by three edges and three nodes, and isadjacent to one to three other triangles on the surface. TINtriangles can be used to derive aspect and slope information, andmay be attributed with tag values.

variogramA function of the distance and direction separating two locationsthat is used to quantify autocorrelation. The variogram is definedas the variance of the difference between two variables at twolocations. The variogram generally increases with distance and isdescribed by nugget, sill, and range parameters.

variographyThe process of estimating the theoretical variogram. It beginswith exploratory data analysis, then computing the empiricalvariogram, binning, fitting a variogram model, and usingdiagnostics to assess the fitted model.

vertical exaggerationA multiplier applied uniformly to the z-values of a three-dimensional model to enhance the natural variations of itssurface. Scenes may appear too flat when the range of x- and y-values is much larger than the z-values. In most cases, settingvertical exaggeration can compensate for this apparent flatteningby increasing relief.

viewerAn additional window that allows you to view the 3D data in ascene from another angle. You can have multiple viewers in ascene or globe.

GLOSSARY 361

viewshedThe viewshed identifies the cells in an input grid that can be seenfrom one or more observation points or lines. This is useful forapplications where the visibility of an object is important, such asfinding well-exposed places for communications towers, orhidden places for parking lots or other facilities.

volumeThe space (measured in cubic units) between a TIN surface and aplane at a specified elevation. Volume may be calculated above orbelow the plane.

walk modeIn ArcGlobe, a navigation mode that allows navigation on a globeclose to the ground, simulating walking.

Z factorA conversion factor used to adjust vertical and horizontalmeasurements into the same unit of measure. Specifically, thenumber of vertical units (z-units) in each horizontal unit. Forexample, if a surface’s horizontal units are meters and its elevation(z) is measured in feet, the z-factor is 0.3048 (the number of feet ina meter).

z-valueThe value for a given surface location that represents an attributeother than position. In an elevation or terrain model, the z-valuerepresents elevation; in other kinds of surface models itrepresents the density or quantity of a particular attribute.

363

12Index Symbols

3D AnalystArcGIS extension 3

3D contour graphicscopy from map to scene 155

3D featureclass

creating 122creating 177

by digitizing 179defined 353

3D geometryfeatures with 187

3D graphic contour lines 1553D graphics

adding to a scene 184changing default 291creating 122, 177creating by digitizing over a surface 180defined 353pasting into ArcScene 184using in ArcScene 180

3D line featureprofiling 166

3D line graphicadding to a scene 184

3D line graphics, digitizing 2873D model 258, 353

importing 2633D point graphic

adding to a scene 184digitizing 286

3D polygon feature limitation 1793D polygon graphic

adding to a scene 1843D properties

of layers 1073D shape 3533D style 261, 353

organizing 281

3D symbol 258, 353creating and modifying 283importing models

importing other formats 263making 263offset 266placement 265scaling 268scaling in ArcGlobe 331symbolizing lines 275symbolizing points 272symbolizing polygons 278types 258

3D text 289digitizing 289

3D View previewdata appears flat 111in ArcCatalog 109

3D View toolbarin ArcCatalog 109

3D viewing propertiesBase Heights tab 117Extrusion tab 117Rendering tab 117

A

Adding3D graphics to a scene 184a single band

of a multiband raster 130a viewer to a scene 205data from ArcCatalog 182data from ArcMap 183data in ArcScene 182depth in 2D 164features to a TIN 101, 104selected features to a TIN 104

Adjust Transparency toolin ArcMap 143


Advanced parametersin kriging 94

Altitude 353described 223for scene illumination 222in hillshading 162setting for scene illumination 223

Analysis maskand nodata 97described 97

Analysis resultsspecifying location to save 96

Analyzingsurfaces 145visibility 158

Animated rotation 216, 218starting 219

Animation 353Animation Manager 354Application-level options, ArcGlobe 318, 340ArcCatalog

basics 108extended by 3D Analyst 3managing 3D data 107opening a scene from 121starting ArcScene from 121

ArcGlobeIntroduction to 301

ArcMapadding data from 183adding layers from 183copying 3D graphics from 184displaying surfaces 123extended by 3D Analyst 3

ArcScene3D viewing application 3displaying surfaces 123introduction to 3pasting 3D graphics to 184simplified symbology of layers 183

Areadefined 354

Aspectcalculating 152defined 354deriving from a surface 153described 148drawing TIN faces by 134quantifying the shape of a surface 148raster calculation 148rendering a TIN 123TIN calculation 148

Attribute tableseeing geometry type in 187

Attributesdefined 354of features 185selecting features by 231setting base heights from 118, 185storing z-values of features 185

Autocorrelationdefined 354

Azimuthdefined 354described 222for scene illumination 222in hillshading 162

B

Backgrounddefined 354options

ArcGlobe 335setting color of in rasters 128values in a raster 132

Background (raster)rendering 123

Background colorchanging for scene 220of a scene 182, 216setting the default 221

Band colorschanging in a multiband raster 130

Barriersin IDW interpolation 82

described 89Base height

defined 354examining for a layer 186not applied in ArcMap 183of raster layer 193setting for a raster 124setting for feature layers 186setting for raster layer 194setting from a surface 189setting using a surface 119setting using an attribute 118, 187

Base resolutionof raster 193

Bindefined 354

Breaklineshard 101input features for a TIN 101soft 101use of 101

Browsingdata in ArcCatalog 108

Building a TIN 103

C

Cache optionsArcGlobe

application level 342Caching in ArcGlobe 349Calculate

base height 187extrusion expression 190scene vertical exaggeration 217

Calculate from Extentscene vertical exaggeration 217

INDEX 365

Calculated valueadding to base height 197

Calculating aspect 152Camera 113

defined 355Capturing perspective views in a scene 241Capturing views to make an animation 241Catalog tree

defined 355Categorical raster

defined 355discussed 127

Cell sizefor analysis results 100of base surface 194

Centering 113shortcut 113

Changingband colors 130classes

in reclassifying data 170illumination properties quickly 222input ranges to unique values

in reclassifying data 172the background color 220the band color assignments 129the classification of input ranges 172the interactive selection method 229the light source 144the rotation speed 219the scene extent 225the scene illumination 222the slope of a TIN surface 136the vertical exaggeration 217

Classifyraster data 123

Clearing an animation 241Clip polygons

creating TINs with 102Closing a viewer 205, 206Color

background of scene 216

Color (continued)setting for background 132setting for nodata 132

Color Rampfor raster 128setting for raster 126

Color Schemesetting for raster 127

Colorslocking a symbol layer 283

Complex datarendering performance 198

Compression, elevation 347Compression, lossy spatial 346Compression options 345Computing hillshade 162Constant

adding to base height 197extruding features to a 120

Contents tabdescribed 108

Continuous rasterdefined 355discussed 126drawing using a color ramp 126

Contourcreating 3D graphics 155creating a single contour 155described 149, 154using in a scene 154

Contour linedefined 355

Contour linesadding to a scene 184representing surfaces with 148

Contour toolcreating a single contour 149

Contrastdescribed 224for scene illumination 222stretching a raster 128

Controlling when a layer is rendered 198

Convertingraster data to features 175raster data to TIN data 105raster data to vector data 174TIN data to features 176TIN data to raster data 106TIN data to vector data 174units for z-values 196z units to x,y units 196z-values 196

Coordinate systemfor analysis results 98of a scene 227predefined 228

Coordinatessetting scene extent using 226

Copy3D graphic in ArcMap 184scene to clipboard 233

Copyinggraphics from ArcMap 184

Copying and pasting 3D graphics fromArcMap 184

Creating3D features 177

by digitizing over a surface 1793D graphics 177

by digitizing over a surface 180a 3D thumbnail 116a hillshade raster 163a keyframe 243

of camera properties 244of layer properties 245of scene properties 243

a layer 117a line of sight 160a new scene 182a single contour 157an animation 238, 240TINs

described 101


Culldefined 355

Custom conversionfor z-values 196

D

Dashed linesnot applied in ArcScene 183

Dataadding from ArcCatalog 182adding from ArcMap 183adding to ArcScene 182rendering performance 198

Data, elevation 302Data, feature 302Data, image 302Data types, ArcGlobe 302Default

location for temporary rasters 96Default background color

setting 221Default color

of bands in multiband raster 131Default layers, system 305Default layers, user defined 304Defining

the 3D properties of a raster layer 194the z-values for a layer 186

Degree and percent slope 151Degree slope 150Degrees

measuring aspect 152Deriving

a hillshade of a surface 163a viewshed 161aspect 153contour lines 149contours 156features height from a surface 177features height using an attribute 178slope 151

Digitizingcreating 3D features 179

Discontinuousrasters 193

Disk cache 343defined 355

Displaying2D data in 3D 117Map Tips

for features 147for surfaces 146

TIN edges with the same symbol 142TIN nodes

by tag value 140with a single symbol 140

TIN nodes by Tag value 140Draped layer

defined 355Draping

2D features over a surface 186a raster on a surface 124defined 355features

in scene 185Drawing

TIN edges grouped with uniquesymbol 142

TIN faces by aspect 134TIN faces by elevation 133TIN faces by slope 136TIN faces by tag value 138TIN nodes by elevation 140

Drawing prioritydefined 355

E

Edgedefined 355drawing with unique values 142rendering a TIN 123TIN component 79

Editing a 3D feature class 122Effects toolbar

in ArcMap 143Elevation

displaying TIN faces 133Elevation layer 322

defined 355Empirical semivariogram

fitting a model to 85Empty feature classes

creating 122Empty shapefile

creating 122Enhancing performance

rendering 198Erase polygon

creating TINs with 102Examining the base heights of a layer 186Exponential

semivariogram model 85Exporting

a graphic of a scene 233a VRML model 234an animation to a video file 253

Extentchanging for a scene 225for analysis results 99of scene 216setting for a scene 225setting using coordinates 226

Extruding featuresin a layer 190in scenes 185using a constant 120using an attribute 120using an expression 120

Extrusionapplying in different ways 191defined 355described 120expression

calculating 120, 190

INDEX 367

Extrusion (continued)expression (continued)

loading 120not applied in ArcMap 183

F

Facedefined 356

Featuretypical geometries of 185

Feature classadding to a scene 182creating 3D shapes 122

Feature datadescribed 185using in a scene 185

Feature data and 3D 185Feature height

from an attribute 178Feature layer

rendering in 3D 186Features

attributes of 185deriving from rasters 174deriving from TINs 174displaying in 3D 185lacking z-values 185selecting by attributes 231selecting by location 232selecting in a scene 229shape 185

Features, rasterized 329File extensions

of coordinate systems 228Fill polygons

creating TINs with 102Finding out the coordinate system

for a scene 227Finding the steepest path 167Fitting a model

empirical semivariogram 85

Fixed Search Radius 87Flat surface

2D features initially rendered on 186raster initially drawn on 194rasters rendered as 186

Floating layer 324defined 356

Full cachedefined 356

Full extent 112Full extent, setting the default view in

ArcGlobe 341

G

Geography viewin ArcCatalog 109

Geometryof features 185

Geospecific modeldefined 356

Geotypical modeldefined 356

Global mode 313defined 356

Globedefined 356new

creating 306Globe document 308

defined 356Globe properties 333

defined 356Globe terrain

defined 356Globe view

defined 356Graduated colors

used in ArcScene 183Graduated symbols

used in ArcScene 183

Graphicexporting a scene 233

Graphic elements, changing properties 290Graphics layers 293Grouping entries

in reclassifying data 171

H

Hard breaklinesdescribed 101

Heightsoffsetting in a layer 197

Hidea viewer 206

Hillshadeadding depth to 2D maps 164creating 163creating a raster 149defined 356described 148, 162on the fly 149surfaces 148

Hillshadingdefined 356

Histogramwhen stretching raster 128

Hullsdescribed 102in TIN creation 102

I

Identify 146Identifying

features 146surfaces 146

IDW (Inverse Distance Weighted)defined 356described 81details 82


Illuminationof a scene 182, 222setting the altitude 223setting the azimuth 222settings for a scene 149

Illumination contrastsetting 224

Illumination options, ArcGlobe 337Illumination properties

of scene 216Image

defined 356draping over a surface 193raster 193setting base height from a surface 185

Importing 3D models 263Input features

building a TIN 101Input ranges

in reclassifying data 172Interpolate

line 179, 180point 179, 180polygon 179, 180

Interpolating usingIDW

fixed radius 90variable radius 89

Natural Neighbors 95spline

regularized 92tension 91

Interpolationassumption of 80creating surface models 77defined 357described 80Kriging 93

Interpolation methodsavailable

described 81available in 3D Analyst 77

Inverse Distance Weighted (IDW) 357defined 356described 81details 82

K

Keyframedefined 357

Keyframes 243Kriging

advanced parameters 94defined 357described 81details 83fixed radius 94interpolation 93methods 88Ordinary 88, 93Universal 88, 93variable radius 93

L

Lagdefined 357

Lag sizein kriging 94

Landmarksrendering simple layer during

navigation 198Launch ArcScene 121Layer

adding a constant to base height 197adding from ArcMap 183adding to ArcScene 182creating in ArcCatalog 107default 301, 303defining 3D properties of 194defining z-values 186draped in ArcGlobe 323

Layer (continued)examining base heights of 186extruding features in 190globe display properties 328rendering only during navigation 199rendering only when stopped 198shading 144symbology of 183zooming to 318

Level of detailin ArcGlobe 344

Line featuresused to represent 185

Line of sightadding to a scene 184and color of line 158creating in ArcMap 160defined 357described 158pasting into a scene 158

Loadingan ArcScene Animation file 254remap table for reclassify 170

Locationselecting features by 232

Lockingsymbol layer color 283

Lookup codesusing tag values to store 138

M

Major rangein Kriging 94

Makinga camera flyby from a path 247a group animation 246a layer transparent 143a prediction 86animations from paths 247group animations 246

INDEX 369

Managing3D data with ArcCatalog 107scene viewers 205viewers 206

Map contours 154Map Tips

displaying for features 147displaying for surfaces 146

Maskfor analysis results 97

Mass pointsinput features for a TIN 101

Memory cachedefined 357

Metadata tabdescribed 108

Minimum Countin fixed radius IDW

described 90Modeling shadows 163Moving a layer along a path 248Multiband raster

adding a band 130as RGB composite 123band color assignment 129turning bands off 130

Multilayer symbolsnot applied in ArcScene 183

Multipatchautomatically rendered in 3D 186

Multiple viewer windows 204

N

Natural Neighborsdescribed 81interpolation

described 95Navigate

defined 357Navigating, ArcGlobe 301, 313

Navigating in 3D 111Navigation

rendering a layer only during 199rendering a layer only when stopped 198rendering simple layer during 198

NoDataand analysis masks 97defined 357in reclassifying 173reclassifying data 169rendering 123setting color in raster 128unknown values in a raster 132

Nodedefined 358drawing TIN nodes elevation 140rendering a TIN 123TIN component 79

Nuggetdefined 358in Kriging 94semivariogram 86

Number of columnsof base surface 194

Number of pointsdescribed 92in spline interpolation 82in tension spline 91

Number of rowsof base surface 194

O

Observer 113defined 358

Observer offsetdefined 358described 160

Offsetdefined 358in deriving contours 156

Offsetting the heights in a layer 197On-demand cache

defined 358Opening an existing scene from

ArcCatalog 121Ordinary Kriging 88Orthographic view

defined 358Output cell size

for analysis results 100Output extent

for analysis results 99Overriding default cell size 100

P

Page Downanimated rotation 219

Page Upanimated rotation 219

Parametersin Kriging 94

Partial cachedefined 358

Partial sillin Kriging 94

Paste Layerinto ArcScene 183

Pasting3D graphic in ArcScene 184graphics from ArcMap 184

Pathdefined 358

Percent slope 150Performance

rasampling base surface 194Performance enhancement

rendering 198Perspective view

defined 358Playing back an animation 242


Point featuresused to represent 185

PointZ 111, 179, 185, 187automatically rendered in 3D 186

Polygon featuresused to represent 185

Polygon graphics, digitizing 288Polygons

input features for a TIN 101PolygonZ 111, 179, 187

automatically rendered in 3D 186PolylineZ 111, 179, 187

automatically rendered in 3D 186Power

in IDW interpolation 82described 89

Pre-processed cachedefined 358

Predefinedz-unit conversion 196

Preview tabdescribed 108viewing 3D data in ArcCatalog 107

Previewingdata in ArcCatalog 108

Primary display fieldshown in Map Tip 147

Printing a scene 235PRJ file (projection file) 228Profile

use of 166Profile graph

defined 358Profiling a 3D line feature 166Projection file (PRJ) 228Properties

of scene apply to all viewers 216setting 3D properties of layers 186setting for a scene 216

Properties, globe layer 320Property editor, 3D Symbol 264

R

Radius typein IDW interpolation 82

Rangedefined 358semivariogram 86

Rastercategorical 127cell size 78continuous 126converting to TIN 105data and 3D 193defined 359deriving contours 149described 78draping over a surface 124drawing using color ramp 126hillshade 163image 78initially rendered at 0 plane 186layer

defining 3D properties of 194setting base height 194

locational precision 78setting base heights for 124symbology 123tab 131thematic 78unknown values 132ways of displaying 125

Raster resolution 194, 359defined 207

Rasterized feature layer 359Reclassifying data

and Nodata 169described 169

Recording and playing back animationtracks 242

Recording navigation to create ananimation 242

Red-Green-Blue (RGB)composite 129

Regularizedspline

described 92spline interpolation method 83

Relief shadingdefined 359

Renderinga layer

only during navigation 199only when navigation is stopped 198

controlling when a layer is shown 198not applied in ArcMap 183performance enhancement 198tab 144, 198, 199

Replace polygonscreating TINs with 102

ReplacingNoData values 170values based on new information 170

Resamplebase surface for draping raster 194

Resolutionof base surface 194

Restorea viewer 206

RGB (Red-Green-Blue)composite 129

RGB compositedisplaying multiband rasters 123

Rotationanimated 216, 218speed

changing 219of scene 218

starting 219Runoff patterns

and steepest path 167

INDEX 371

S

Savingan animation 238, 252

by exporting tracks to an ArcScene 252in a scene document 252

remap table for reclassify 170setting a default location 96

Sceneadding feature classes 182background color 182changing background color 220coordinate system of 227copy to clipboard 233creating 182default background

color 221, 222, 223, 224, 225, 226, 228defined 359exporting as a graphic 233exporting VRML 234extent 216

changing 225illumination 182

changing 222illumination properties 216managing viewers 205opening from ArcCatalog 121printing 235properties

apply to all viewers 216selecting features in 229setting properties of 216vertical exaggeration 182viewers

managing 205Search Radius 87

fixed 87variable 87

Search toolfinding data in ArcCatalog 110

See-through position 332

Selectingfeatures

by their attributes 231by their location 232in a scene 229interactively 229, 230

the surface to supply z-values 180Selection method

changing 229Semivariogram 84

defined 359nugget 86range and sill 86

Semivariogram modelstypes of 85

Settinga layer's base heights using a surface 189a raster's base heights using a surface 194an analysis mask 97base heights using a surface 119base heights using an attribute 118layer properties 117the background color 132, 220the base height from an attribute 187the coordinate system for analysis

results 98the default background color 221the default color band assignments 131the extent to a layer 225the extent using coordinates 226the illumination altitude 223the illumination azimuth 222the illumination contrast 224the NoData color 132the output cell size 100the output extent 99the properties of a scene 216the Snap extent 99values to NoData 173

Shading 144a layer 144a raster surface in a scene 165

Shading (continued)a raster with a hillshade 164areas in a scene 165of raster 193surfaces 123TIN faces 144

Shapeof features 185

Shapefilecreating 3D shapes 122

Sharing animations 239, 254Show

a viewer 206Sill

defined 359semivariogram 86

Simple layerrendering during navigation 198

Simple symbolsused in ArcScene 183

Slopecalculating 150defined 359described 148expressed as percentage 150expressed in degrees 150quantifying the shape of a surface 148raster calculation 148rendering a TIN 123TIN calculation 148

Snap extentsetting 99

Snapshotcopy to clipboard 233

Soft breaklinesdescribed 101

Spatial autocorrelationdiscussed 84

Specifying a Z factorin hillshading 163

Speedchanging for scene rotation 219


Sphericalsemivariogram model 85

Splinedefined 359described 81details 82

Starting animated rotation 219Steepest path

adding to a scene 184checking TIN integrity 167defined 359finding 167

Stereo mode, viewing in 181, 212Stereo viewing 212Stretch

defined 359described 128raster data 123type 128

Structural analysisin Kriging 84

Style contentscreating

symbols 283Styles

editing database in Microsoft Access 283Styles, saving current 280Surface

analyzing 145area 4defined 360described 78displaying 123model

creating 77described 78raster 77setting base heights of features 185TIN 77

setting feature base heights from 189using to set base heights 119

Surface modedefined 360

Surface-to-vector transformationreclassify step 169

Symbol, geospecific 260Symbol, geotypical 260Symbol Property Editors

described 283Symbolizing

TIN features 133Symbology

of raster 193simplified in ArcScene 183

Symbolscolor

locking 283creating 283layers

drawing 283locking 283

propertiesdescribed 283

units 283

T

Table of contentsArcGlobe

Layer types 301, 309Table of contents options

ArcGlobe 348Table view

in ArcCatalog 109Tag value

described 138displaying TIN faces 138

Taking a snapshot of a scene 233Target 113

defined 360Target offset

defined 360described 160

Target, using to simplify navigation 316Techniques, including inverse distance

weighted 357Temporary rasters

deletion of 96Tension

spline interpolation method 83Tension spline

described 91The camera, the observer, and the

target 113, 238Thematic raster 193

draping over a surface 193drawing with unique values 127

Thumbnailcreating 3D thumbnails 107

Timing Properties in the AnimationManager 251

TIN (triangulated irregular network)adding features 101, 104adding selected features to 104automatically rendered in 3D 186components of 79creating 101defined 360deriving contours 149described 78displaying elevation 123edges

drawing with unique symbols 142face shading 144faces

displaying by slope 136displaying elevation 133drawing by aspect 134drawing by tag value 138

integritychecking with steepest path 167

nodesdrawing by elevation 140

resolution 79symbology 123

INDEX 373

Track 360Transparency

setting for hillshade 164Transparent

making a layer 143surfaces 123

Trenddescribed 81

Triangledefined 360TIN component 79

Triangulated irregular network (TIN)adding features 101, 104adding selected features to 104automatically rendered in 3D 186components of 79creating 101deriving contours 149described 78displaying elevation 123edges

drawing with unique symbols 142face shading 144faces

displaying by slope 136displaying elevation 133drawing by aspect 134drawing by tag value 138

integritychecking with steepest path 167

nodesdrawing by elevation 140

resolution 79symbology 123

Triangulationcreating surface models 77

Turning bands on and off 130Turning on the Animation toolbar 240

U

Ungrouping entriesin reclassifying data 171

Unique valuesdrawing thematic rasters 127raster data 123

Unitsconverting for z-values 196symbol 283

Universal Kriging 88Universal Transverse Mercator (UTM) 196Unknown values

symbolizing in a raster 132Using

3D graphics in ArcScene 180animated rotation 218built-in z-values of a layer 187contours in a scene 154hillshading

for display 162in analysis 162

the Animation Manager 249to access keyframe properties 249to access track properties 250to modify timing properties 251

UTM (Universal Transverse Mercator) 196

V

Variable radiusin IDW interpolation

described 89Variable search radius 87Variogram

defined 360Variography 84

defined 360Vertical accuracy

converting raster to TIN 105

Vertical exaggeration 216applied to all layers in scene 217changing 217defined 360of a scene 182

Vieweradding 205close 206closing 205defined 360hide 206managing 206restore 206show 206

Viewer Manager 206Viewer windows

multiple 204Viewing

a scene from different angles 204a surface

to understand its shape 148rasters in 3D 194thumbnails 116

Viewsheddefined 361deriving 161described 158input feature types 161

Visibilityanalyzing 158

Visualizingfeatures in 3D 185relationships 193

Volume 4defined 361

VRMLexporting to 234


W

Walk modedefined 361

Walk tool 319Weight

for Regularized splinedescribed 92

in tension spline 91

Z

Z factorconverting TIN to raster 106defined 361in calculating slope 151in deriving contours 156in hillshading 163

Z-unit conversion factorof raster 193of TIN 136

Z-unitsconversion

predefined 196Converting to x,y units 196

Z-valueconverting units of 196custom conversion 196defined 361defining for a layer 186defining for features 186defining for raster 186, 194described 78of features

from surface 179offsetting 197setting from an attribute 187stored in attributes 185stored in geometry 185using from feature geometry 187

Zoomingshortcut 114, 115to a target 114

Using 3 d_analyst

Technology

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