barcelona exterior tutorialSetting Material Properties for Water Finally, we’ll set up the water....

barcelona exterior tutorial

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�SU Podium - Barcelona Exterior Tutorial

IntroductionAlthough Podium is about as easy as rendering gets, sometimes if you want to get really good images, you need to put in a little effort. It is true that exterior scenes are the easiest to render in SketchUp, but sometimes the resulting images seem to be missing something com-pared with some of the best images in the gallery.

This tutorial will go through all the various steps to creating a con-vincing rendered image. We are going to use Mies van der Rohe’s Barcelona Pavilion as a tutorial subject model. This modern design icon is a perfect subject because apart from its status as one of the all time great pieces of modern architecture, it has all the features we need to consider in rendering, lighting, texturing, materials properties, environment setup in a very simple form which shouldn’t take forever to render.

The tutorial scene is a modified version of the one posted on the Google 3D Warehouse. The tutorial scene can be downloaded here.

Barcelona Pavilion - A final render.

3SU Podium - Barcelona Exterior Tutorial

Environment SetupThe first thing we are going to do is set up the environment, that is, the sun and sky. There are two basic options for an environment, you can use the SketchUp sky or you can use a custom background colour.

First of all we’ll set up the SketchUp Sky. Podium uses the SketchUp sky settings to create an external ‘skydome’ representing the sky, so the settings we use here are important. We’ll start from scratch set everything up from first principles, so go to the styles tab and create a new style. Next, click on the ‘Edit’ tab and select the middle icon, which sets up the background. Make sure the ‘Sky’ box is checked, and click on the coloured square immediately to the right of the check-box. In the ‘Choose Color’ dialog that appears, switch to the RGB option from the ‘Picker’ drop down menu. Set the colours to [RGB colours required]. These values will give you a reasonably accurate colour temperature for the sky. You can read a little more about this here on Wikipedia. For an overcast sky, values of [insert values] are more representative. Please note, when using sky do not switch on the ground tab but instead build a base so the model sits on this. When you don’t use sky, switch on the ground tab, so light won’t penetrate from below.

The next thing to do is set up the sun and shadows. Display the Shad-ows dialog by going to the >Window menu in SketchUp, and select-ing the Shadows entry. Figure 1. shows this dialog.

First, make sure Display shadows is checked, and at the bottom of the dialog, also make sure the ‘On faces’ box is checked. Set the Dark slider to around �5. You may notice with the test renders while setting your model up if the quality settings are not set to maximum, that the model will have white burn marks on it. When doing the final render, the higher you push the quality bar in podium, the less the marks will appear.

When you start to use the SketchUp sky in your renders, you may notice some unexpected visual effects like excessive blue colour cast-ing, and ‘artifacts’ (unwanted things that appear in the model and are not related to any geometry) such as lines. The time setting is criti-cal when you use the sky. Currently Podium’s physical sky isn’t quite perfect, and needs setting up carefully to avoid undesirable effects. Setting the time near midday seems to intensify the colour bleeding caused by global illumination to an unacceptable extent. Times of around 10:00am and 3:30pm seem to work quite well.To start with, use a morning setting, pretty early.

If you are using a custom background color, you can set the time to whatever you want, as the pronounced colour washing effect doesn’t occur.

You then need to adjust the month setting until you are happy with the shadows cast. The next stage depends on whether you want an accurate representation of the shadows, or just a nice image! If you

Figure 1: Shadow Settings Dialog Box.


want accurate shadow casting (or as accurate as SketchUp can get) then you need to set the building orientation and location to coincide with the actual site. This varies depending on whether you are using Google SketchUp, or SketchUp Pro. If you just want a nice image, then you can rotate your model until you are happy with the shadow patterns. Try to set up your model so that at least one big face is in shade. These starting stages are crucial, because when your model gets more fully detailed, setting this up at that stage will take longer which may be a little frustrating! So it is worthwhile taking a little time to get things right at the start.

It is probably worth doing a quick test render to check that you are happy with everything so far before proceeding.

Textures and MaterialsGood renders basically rely on good lighting and good textures. Then the model needs a consistent and convincing level of detail. Fortu-nately, as this building is basically simple, we don’t need too much detail.

The Barcelona Pavilion has some very distinctive materials, so we are going to try to make sure that we do a little justice to them in the ren-dered image. Obviously for this tutorial we aren’t going to get things perfect, but we will expend a little time and effort which should be evident in the finished result.

First of all we will find a suitable texture for the white travertine walls. You can either look for this on one of the texture links posted in the Forum, or us Google image search. This is quite a good resource for this type of texture, as there are lots of online suppliers which have previews of their products at a reasonable size. For stone in particular, this can be a really fast way to find just the right sort of texture if you know what you are looking for. I have found the Lightbeige travertine image in Figure 3. with a Google search. This seems about the right texture and a reasonable colour. I have used an Auto adjust colours feature in Irfanview, to improve the colour a bit. You can use your favourite image manipulation program. Google’s Picasa is good too.

Note: Irfanview is an excellent freeware image viewing/processing application, more details are available here.

Figure 3. shows the modified image. Ideally, you would probably en-large the canvas and use the clone brush to avoid the obvious texture repeat, but this will be sufficient for the moment. In some instances we will want to make the texture seamless, but in our case, the travertine is in a series of panels, so we don’t need to do this.

Now we need to import this texture into SketchUp to use as a standard material in Podium. There are two ways of doing this.

Figure 2: The original travertine texture.

Figure 3: The modified travertine texture.


Importing a Texture Option One:

First of all you can go the materials dialog (>Window>Materials) and click on the Create material button. This gives you the material editing dialog shown in Figure �.

If you click on the folder icon to the right of the blank text field. You can then browse to the material you want to use, and the name will appear in the text field. You can then adjust the scale. I have scaled the texture unequally by clicking on the chain icon to the right of the image size. You will notice that in the image, the chain is broken indicating that the image has different settings for vertical and horizontal scaling. This allows you to stretch a texture more or less in a particular direction. I have scaled it so that is twice as wide as it is high. Give the material a name and apply it to the back wall, floor and sides of the pool.

Importing a Texture Option Two:

The other way of getting textures into your model is simply to drag them from your Windows Explorer into SketchUp, it will be a grouped image. If you use the scale button on the texture you can size your image before applying it. To apply, simply right click on your image, and select ‘explode’. If you right click again on the exploded texture, you will now see a menu item labelled ‘Texture’. This menu item can be found on any face which has a texture applied. On cylinders, or round shapes, just select show hidden lines and you can select that face.To come back to this, choose texture, by right clicking on the surface. now it gives you options, untick projected. Go to position, and there will be four corners. Dragging each corner gives you different proper-ties to your texture. Green scales and rotates.

Note this only applies for the current face.

Figure 4: Materials settings for the travertine texture.


Setting Material Propertiesfor Glass and ChromeMay people seem to have difficulty getting glass and chrome or mirrored surfaces to look right. Best results seem to be obtained again by using a lightish mid-grey colour and setting transparency (actually it is probably bet-ter to think of this setting as opacity, because completely transparent is 0%, and completely opaque, 100%) to no more than �0%. In reality glass is rarely perfectly clear, and usually has a faint grey tint. You may need to open a window a little to see the difference between a view through glass, and an unobstructed plain one. You might want to experiment with this a little, as you might prefer the results you get with slightly different settings. The settings I have used are shown in Figure 5.

To set reflectivity of the surfaces, you need to highlight the glass, and set reflectivity to between �5 and 35%. Next we’ll set up the chrome colour of the window frames and columns. For chrome, best results are usually obtained by using a darkish mid-grey, with high reflectivity. If you look in the tutorial model, you will see that I have already set the colour. The settings I have used are shown in Figure �. Next, you need to select the materials to receive the chrome material, and set reflectivity to at least 50%. In this building the famous cross-shaped columns and door/window frames all have a chrome finish.

Figure 5: Materials settings forglass.

Figure 6: Materials settings for chrome.


Setting Material Properties for WaterFinally, we’ll set up the water. This can be tricky to get right, as in real-ity, water is seldom smooth, there are usually ripples which reflect the light and the surroundings. Its effects are a combination of the two. In strong sunlight you get little sparkles as each separate surface reflects the sun, and the distorted reflection on the undulating surface. Short of modelling a rippled plane for water, the best solution is to use a good texture. This can be notoriously difficult to get right.

Even if you use an undulating geometric plane, in reality it is likely to be too simple to fully simulate the effects you get in real life, and if it was complex enough, it would take a long time to render. So, it comes down to getting a really good texture map. It isn’t particularly insight-ful to say that there are many different types of water effects, and the textures for them depend on the depth of the water, the surface under-neath, extent of surface disturbance, and degree/type of reflectivity.

However people frequently choose an unsuitable texture for water. If you have a shallow pond with mud at the bottom, the water is likely to look brownish, and the ripples are likely to be fairly small, because the only disturbance to the surface will come from small insects and wind. Swimming pools tend to have pale finishes at the bottom, so you tend to see refracted patterns of light where sunlight diffuses through the water, hitting ripples which redirect the light in different directions.

These ripples sometimes come from water recirculation pumps un-der the surface creating the characteristic patterns that most people recognise as being associated with swimming pools. The point of this is to illustrate that the characteristics of one type of water can be so totally different to another, that choosing the right texture is absolutely essential to getting a good result. Using a pond water texture for a pool or vice-versa is really not going to get you a good result! If you look at the texture used in Figure � you will see that it has gentle rip-ples in one direction, with a dark background, which is more like a pond or small pool. Actually, the Barcelona Pavilion pool is normally glass-like and fairly ripple-free, but that wouldn’t be much help for a tutorial, so we are going to use a texture which is of more use in gen-eral rendering.

This looks fairly reasonable, so we’ll apply it in the same way we ap-plied the travertine texture. We’ll set the transparency to something like �5% opaque and set reflectivity to around 10 and see how that looks when it renders. My settings are shown in Figure 8. We don’t want to make the surface too reflective because a rippled surface won’t show a clean reflected image. We’ll set quality and jaggy to around �0% to start with.

Figure 7: The water texture used in the tutorial model.

Figure 8: Material settings for the water.


Rendering theModelIn the tutorial model, I am rendering Scene 1. Figure 9 shows how this looks with the SketchUp sun set as described earlier.

You will notice the blueish tint to the ground. This is exaggerated be-cause the floor is a pale colour. The closer the time gets towards midday, the stronger the effect. This render looks okay, but it needs a some sort of context and the blueish tint to the surfaces is a little strong. This is partly because the floor surface is a pale cream colour. A darker floor will not display this same colour cast nearly as much.

Rendering with a coloured back-ground does not have this drawback, but the resulting images seem to lack intensity. Figure 10 shows how this differs from the render using the SketchUp sky. You can choose to use whichever method you prefer.

Figure 9. Initial render using SketchUp sky.

Figure 10. Another render of the same scene, but using a custombackground colour.


Both scenes are okay, but really could benefit from adding a back-drop. You can do this in Podium, but better results are usually obtained by adding it in your image editing pro-gram like PhotoShop, PaintShop Pro or the Gimp.

If you want to do this within Podium, you have to create a plane as a backdrop to apply a background im-age to. If you switch the layer ‘back-ground’ on and render, you can see how I have set this up. Figures 11 and 1� show the end result. Obviously the quality of the result depends on the quality of the image you use as a backdrop. Note that SketchUp’s photomatch feature isn’t supported by Podium at the moment.

When you insert a texture and ap-ply it in this way, you need to set the properties of the images such that it does not cast shadows. This is done by selecting the background image, then displaying the Entity Info dialog (>Window>Entity Info) shown in fig-ure 13. You will note that in this case I have set the face so that it does not receive shadows. You may choose to do this if your backdrop image represents a vertical surface that will receive shadows, and if it is close enough to the model so that shad-ows are cast onto it.

Figure 11. A render using a background image in Podium with custom back-ground colour.

Figure 12. A render using a background image in Podium with SketchUp sky.

Figure 13. The Entity Info dialog showing how the face is configured so as not to cast shadows


The final image in Figure 1� shows what can be done with some good work in Photoshop. This can be quite time-consuming, but for the ab-solute best results, this is the approach that you probably need to consider. Post-processing offers all sorts of opportunities to adjust the colour balance, brightness, insert a background image, and remove any small ‘artifacts’ produced by the render.

Figure 14. A finished render, with image processing in Adobe Photoshop.Image courtesy of Jacques Cleghorn (silver shadow).

PRODUCTION:Written By: Jim Allen (bigstick)Publication Design: Darryl Jones (zorro)

SU Podium is a trade mark of Cadalog, Inc.SketchUp is a registered trade mark of Google.

Contents of this document are copyrighted to © �00�-�00� Cadalog, Inc. All rights reserved.

barcelona exterior tutorialSetting Material Properties for Water Finally, we’ll set up the water....

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