[heading]10.4. Lighting the 3D model[/heading]
One of the significant additions to the CS5 3D engine is the ability to use IBL (image based lighting). That means that you can take any photographic image and utilize its Color and Luminance properties to light the scene so that your models will actually look as if they were photographed within the same environment. For more information on image based lights, see Chapters 1 and 5. Let's start with lighting the car.
Step 1: Click on the “add new light” icon and select “New Image Based Lights”. Now that the light has been added to the scene, all we need to do is select the image that it will use to light the model. If you select any light tool, take note that a 3D navigational sphere for the IBL light will be displayed for you to facilitate navigating the light.
Note: Although it is customary to add 360 degree panoramic HDR images, it is important to know that you can use any bitmap image; that is what we will do in this situation.
Inside the 3D Lighting panel click on the add image icon that is next to the “Image” title located below the color swatch. Navigate to your downloads folder and select “ibl lightsource.jpg.” This is the merged imagery of the background scene as shown in (Figure 10.34).
Step 2: It is a good idea to match the ambient light in the scene. If you like, select any color so that you can see how this feature will affect the car; however the reddish bluish horizon was chosen in this example (Figure 10.35).
Step 3: Let's take a look at the actual surface properties on the concept car. The 3D Materials panel will display all of the separate 3D surfaces that are attached to this model. As you can see there are quite a few (Figure 10.36). Through the 3D Materials panel you can select each 3D mesh and view its surface. In this example “mesh643-geometry” is chosen and below is its surface titled “Gris_argent_Rendering.”
Note: These titles were the originals given when the car was created in its native 3D program. However, you can change them by double-clicking on their titles and typing in the new name.
Step 4: Now we are going to add some ambient lighting to the City Block so select that layer and this time choose a more bluish color within the clouds (Figure 10.37). Since this portion of the buildings is mostly in shadow we will allow it to be dominated by the bluish temperature that often dominates shadow regions of a photographic image.
Next we will add a wet looking surface to the street.