Up to now, you’ve only used one light source called a Distant Light to create a sun. You have two other light sources available to help simulate light: point-light sources and spotlights. This section will show you some examples of how you can use these types of light sources along with some imagination to perform any number of visual tricks with the(X\.
Simulating the Interior Lightig of an Office Building
Our current rendering shows a lifeless-looking office building. It’s missing a sense of activity. You might notice that when you look at glass office buildings you can frequently see the ceiling lights from the exterior of the building-provided the glass isn’t too dark. In a subtle way, those lights lend a sense of life to a building. To help improve the image you’ll add some ceiling lights to the office building.
You’ve already supplied the lights in the form of square 3D Faces arrayed just at the ceiling level of each floor as shown in Figure 17.12. In this section you will learn how to make the ceiling lights appear illuminated.
1. Start by assigning a reflective material to the squares. Choose View > Render > Materials and then dick the Materials Library button.
2. In the Materials Library dialog box locate and select white Plastic from the Library List at the right and then click Import.
3. Click OK to exit the Materials Library dialog box. Then in the Materials dialog box highlight White Plastic in the list to the left and click the By Layer button.
4:- In the Attach by Layer dialog box, make sure White Plastic is highlighted in the Select a Material list to the left; then click the Clglite layer in the Select Layer list to the right.
5. Click the Attach-> button. The word White Plastic appears next to the Clglite layer name in the Select Layer list.
6. Click OK to exit the Attach by Layer dialog box and then click OK to exit the Materials dialog box.
You now have a reflective white material assigned to the ceiling fixtures. But the reflective material alone will not give the effect of illuminated lights. You need a light source that can be reflected by the fixtures giving the impression of illumination. For this you’ll use a point-light source.
1. Choose View> 3D Viewpoint> SE Isometric to get an Isometric view of the model.
2. Zoom into the base of the office building so your view is similar to Figure
3. Choose View Render >: Lights. Then in the Lights dialog box select Point Light from the New drop-down list; then click the New button. The New Point Light dialog box appears.
4. Enter Pointl for the light name. Then enter 300 in the Intensity input box.
5. Click the Modify button and then select a point at the very center of the office building base as shown in Figure 17.13.
6. Click OK to exit the New Point Light dialog box and then click OK in the Lights dialog box.
7. Choose View >Named Views. Then at the Named Views dialog box select 3DFront and click the Restore button.
8. . Click OK to exit the Named Views dialog box.
9. Go ahead and render the view. After a minute you will have a rendered view similar to Figure 17.14.
The new point light in conjunction with the 3D Face light fixture adds a sense of life and depth to the office building. Notice that despite the fact that the light is located inside the box representing the office core, the light manages to strike all the lights of all the floors as if the floors and core were transparent. Since you didn’t turn on the Shadow feature for the point-light source its light passes through all the objects in the model.
There is even light falling on the granite facade building illuminating the inside of the arched entrance. This shows that with careful use of lighting you can bring out some of the detail in the Facade model that might otherwise get lost with the distant light source.
Of course you can use point-light sources in a more traditional way representing light bulbs or other nondirectional light sources. But by playing with light source location and shadow you can create effects to help enhance your rendering