Business and Computing Deanery

3D Modelling Week 4

Materials

3D Modelling 2

Aims of today Discuss your assessments

Presentation Portfolio

Materials Why materials Working with materials in 3ds max Shaders and rendering Surface properties Applying maps

Bitmaps Procedural

Libraries Exporting materials

3D Modelling 3

Your portfolio Create a series of non-trivial and novel

3D applications Build upon concepts taught in the

tutorials Submission of paper screenshots Submission of electronic version

On the disc you are expected to provide: Webpages with critical reflection and links to your

models Your models Copy of your presentation

3D Modelling 4

Portfolio 4An interactive model of an object, added to your room. The subject of this object will be given to you in class. Marks will only be awarded for elements identified by you in your documentation and that go beyond the scope of the tutorials used in the teaching session.

You choose one from: A BBC Micro computer

http://en.wikipedia.org/wiki/Bbc_micro

A trading starship, a Cobra Mark III, from the game Elite

http://en.wikipedia.org/wiki/Elite_(computer_game)

A room or building from the Hope campus

3D Modelling 5

Materials - a context… To model furniture how would you

apply material to an object to model: A shinny metal chair? Wood surface on a chest of drawers? Marble vase? A glass table top? A tumbler with blackcurrant squash?

3D Modelling 6

…and more To display a wooden bowl, full of

oranges? A video recorder? A stone fireplace? A metal light fitting, with the light

turned on? A TV? A plastic chair? A magazine?

3D Modelling 7

Concepts Consider modelling a brick wall Can you think of three ways to do it? Which would look best?

3D Modelling 8

Using materials in 3ds max Use the library that comes with the

software Or make you own

Simple material Using a material texture Use a map

Apply sections or in particular ways

3D Modelling 9

Materials Materials are like paint With materials, you make apples red

and oranges orange You put the shine in chrome and the

polish on glass Materials are what make your

scenes look real

3D Modelling 10

Materials and light Light is reflected from the surfaces

of your model Consider how the light and materials

will interact Will it reflect its surroundings? Will it be bumpy or smooth? Old, clean or dirty?

3D Modelling 11

Material editor Materials

Defined Created Applied

Sample shots Parameters

Shaders Maps

3ds max v7

3D Modelling 12

Standard materials You can create an unlimited number

of materials The most important part of the

material is the shader A mathematical formula that defines

the way that a surface is affected by light

You choose a shader according to the surface you hope to create

3D Modelling 13

Rendering The computer “paints” the result of

calculation onto the screen as an image Takes into account the geometry of the

model, but also Colours Textures Light position, intensity, colour

The viewport is a preview, you need to render the scene to see the materials properly

3D Modelling 14

Shaders and rendering For standard materials, a shader is

an algorithm that tells your software how to calculate surface rendering

Each shader has a unique set of characteristics in order to serve a particular purpose

3D Modelling 15

Maps and the Standard Material Think of the Standard Material as an

easel The shader is the surface type

Canvas, paper, metal Maps are the paintbrushes

Use them to add colour and texture

3D Modelling 16

Rendering modes Wireframe – most basic Flat render – single colour in the middle

of the polygon Gourand or smooth renderer – smoothly

blended object surfaces Phong Blinn Ray tracing – special type

Reflections Radiosity Takes longer to render as it attempts to

physically model a surface

3D Modelling 17

3ds types of shaders Seven shaders used with a standard material

Anisotropic: For surfaces with elliptical, "anisotropic" highlights. These highlights are good for modeling hair, glass, or brushed metal.

Blinn: For rounder, softer highlights than Phong shading Metal: For metallic surfaces Multi-Layer: For surfaces with more complex highlights

than Anisotropic Oren-Nayar-Blinn: For matte surfaces such as fabric or

terra-cotta Phong: For surfaces with strong, circular highlights Strauss: For metallic and nonmetallic surfaces. The

Strauss shader has a simpler interface than other shaders.

Translucent: Similar to Blinn shading, the Translucent shader also lets you specify translucency, where light is scattered as it passes through the material.

3D Modelling 18

Phong Smoothes the edges between

faces and renders highlights realistically for shiny, regular surfaces

Interpolates intensities across a face based on the averaged face normals of adjacent faces.

Calculates the normal for every pixel of the face. 3ds max v7

3D Modelling 19

Blinn shading Blinn shading is a subtle variation on

Phong shading The most noticeable difference is

that highlights appear rounder

3ds max v7

3D Modelling 20

Ray tracing Each pixel is

calculated In 3ds max it uses

mental ray renderer Generate reflections

and refractions Ray tracing traces the

path of rays sampled from the light source

Reflections and refractions generated this way are physically accurate 3ds max v7

3D Modelling 21

Reflections and Radiosity Ray-tracing algorithm takes into

account reflections and radiosity

3ds max v7

3D Modelling 22

Surface attributes Basic material settings

Colour Shininess Transparency

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Standard colour components 1. Specular

The colour of shiny highlights

2. Diffuse The colour of the

object in direct, "good" lighting

3. Ambient colour The colour of the

object in shadow

Some shaders generate the specular colour, rather than letting you choose it.

3ds max v7

3D Modelling 24

Colour Hue

Frequency of the light coming form the object

Saturation How concentrated

the colour is Value

Lightness or darkness of a colour

Additive colour model RGB

3ds max v7

3D Modelling 25

Shininess Overall reflective

nature of the object

Specularity Intensity of the

highlight Glossiness

The size of the specular highlight

Top sphere: Glossiness=100; Specular Level=100

Left sphere: Glossiness=50; Specular Level=50

Right sphere: Glossiness=0; Specular Level=0 3ds max v7

3D Modelling 26

Anisotropic highlights The Anisotropic

shader creates surfaces with elliptical highlights

Good for modelling hair, glass, or brushed metal

3ds max v7

3D Modelling 27

Activity Use a box to create a tray or table top Create a 2 x 3 array of spheres on the

top Save to use again

Create 6 different materials and apply them to your spheres Polished steel, brushed aluminium, red

dull plastic , red shiny plastic………….

3D Modelling 28

Transparency Transparency and

opacity are opposites

3ds max v7

3D Modelling 29

Translucency and refraction A translucent

material transmits light, but unlike a transparent material, it also scatters the light so those objects behind the material cannot be seen clearly

Simulate frosted and etched glass 3ds max v7

3D Modelling 30

Glow Appears to be lit from inside

3ds max v7

3D Modelling 31

Activity Reopen your saved file

Make a partially transparent glowing material Use the translucent shader Select self-illumination

3D Modelling 32

Materials and maps Materials describe how an object

reflects or transmits light Within a material, maps can

simulate textures, applied designs, reflections, refractions, and other effects

3ds max v7

3D Modelling 33

2D maps 2D Maps are two-dimensional

images mapped onto the surface of geometric

objects or used as environment maps to create

a background for the scene Bitmaps can be used as 2D maps Other kinds of 2D maps are

generated procedurally

3D Modelling 34

Diffuse map An image is used

as a diffuse map Applied to the

surface of the object

Overrides the base colour Wood grain Texture of fruit Marble 3ds max v7

3D Modelling 35

Procedural maps Derived from

mathematical equations Simple or complex Do not degrade

when you zoom into them

They are 3D Marble material goes

through an object as if it were solid 3ds max v7

3D Modelling 36

Mapping textures Mapping is a method of projecting

pictorial information onto surfaces It is a lot like wrapping a present

with wrapping paper

3ds max v7

3D Modelling 37

Why use bitmaps? Stick a logo on something Making street scenes or urban

landscapes Use with billboard Used with avatars

The map is generated by a graphic artist

Use with care in real-time modelling Why?

3D Modelling 38

Tiling Repetition of an

image over a large area

Use less memory Can look too

uniform Can get join

patterns3ds max v7

3D Modelling 39

Face mapping Ignores any mapping coordinates Conforms the image to the faces

Select the desired face Apply the image

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Bump map Bump mapping

makes an object appear to have a bumpy or irregular surface

Manipulates the object’s normals Does not affect the

object’s mesh 3ds max v7

3D Modelling 41

Mapping coordinates Use x, y z coodinates

3ds max v7

3D Modelling 42

UVW co-ordinates Most material maps are a 2D plane

assigned to a 3D surface. The coordinate system used to

describe the placement and transformation of maps

Mapping coordinates use the letters U, V, and W The three letters preceding X, Y, and Z

in the alphabet.

3D Modelling 43

Activity Add a procedural map to your scene

Wood Marble

Change the colours and grain

Add a bitmap to a material in your scene

3D Modelling 44

Material libraries Materials used in a model are saved

in the max file

The software comes with libraries of materials

Create your own materials Which can then be saved to a library

for use on another project Make a library from a particular scene

3D Modelling 45

Special libraries Ray trace

Attempts to physically model a surface instead of simulating it

Form of rendering that calculates rays of light

Supports advanced transparency parameters such as fog

Architectural Actual physical properties Use with photometric lights to model

real-life objects

3D Modelling 46

Activity Use the material library to add the

following: Clear glass Earth Clouds Mirror

3D Modelling 47

Animated textures Use an animation or video

A model of a TV May loop Think about transitions

3D Modelling 48

Environments You can use an

image as a background Rendering>Environm

ents

3ds max v7

3D Modelling 49

Bitmaps for exported models Exported files do not always take

colours or textures with them Bitmaps can be better, but you need

to collect them With 3ds max use Utilities > More… > Bitmap/Photometric

Paths > Path Editor > Edit Resources

3D Modelling 50

Activity Export your model as VRML Collect all the maps into a ‘maps’

folder

3D Modelling 51

Covered today Why materials Working with materials in 3ds max Shaders and rendering Surface properties Applying maps

Bitmaps Procedural

3D Modelling 52

Self assessment To model furniture how would you

apply material to create Shinny metal Wood surface Marble A glass table top A tumbler with blackcurrant squash

3D Modelling 53

Self assessment …and more

To display a wooden bowl, full of oranges A video recorder A stone fireplace A metal light fitting, with the light turned

on A TV A plastic chair A magazine

3D Modelling 54

References Giambruno M, (2002) 3D Graphics & Animation,

2nd Edition, New Riders, ISBN: 0-7357-1243-3 Kerlow I. V., (2003) The Art of 3-D Computer

Animation and Effects , 3rd Edition, John Wiley & Sons Inc; ISBN: 0471430366

Murdock K. L., 3ds max7 Bible, Wiley Publishing; ISBN: 0-7645-7971-1

Screen shots taken from 3ds max 7 User Reference and tutorials

Discreet, 3ds max6 fundamentals courseware, Autodesk; ISBN 1-56444-976-9