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The Three Components of Light

Early in our primary education, we learned that when we "see" something, our brains are calculating the effect of light as it bounces off the surface of an object. While the object absorbs a portion of the color spectrum, the remainder is reflected and diffused into the surrounding environment. The light that is reflected gives us information about the object's color and texture. Compare a well-used "alley ball" from your local bowling alley to a new and recently polished counterpart. They're both spheres of the same size and weight, yet the new ball will look sleeker and harder, while the alley ball will give the impression of being slower and heavier.

Light is broken down into three distinct components, known as diffuse, ambient, and specular light. Although the parameters of these components are primarily determined in the Material Editor, it's the lights in your scene that bring them to life. Figure 12.5 shows two standard 3ds max teapots, with slightly different materials applied, which emphasize these components. The file Light Components.max is available on the DVD if you would like to follow along.

Figure 12.2, the absence of either bounced light or a fill light results in the objects' illumination falling off (fading at the edges) in an unnatural way. The left side of each teapot appears to be slightly illuminated by a low-energy bounced light from within the scene. Because a fill light is used to generate the illusion of ambience, the light isn't truly an ambient effect. The necessity of faking a real-world condition within max to accommodate a required look is a common situation.

3ds max allows a default amount of global ambient light to be automatically generated in a scene. This can be adjusted by selecting Rendering > Environment from the Main toolbar and opening the Color Selector by clicking in the Ambient swatch in the Common Parameters rollout (Figure 12.6). Raising the default ambient light level has its rare uses, but it often leaves a scene looking washed out and flat. Try running the Ambient Light RBG values to (255, 255, 255) to see an extreme use (or abuse) of this tool and its effect on the scene. I highly recommend retaining the default value of (0, 0, 0) and creating the ambient light manually.