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Chapter 20: Using Lights and Basic Lighting Techniques

Figure 20.2 shows an elk model that was rendered using different levels of the standard lighting model. The
upper-left image uses the default lighting with no lights. The upper-right image uses only the key light. This
makes a shadow visible, but the details around the head are hard to define. The lower-left image includes
the secondary lights, making the head details more easily visible and adding some highlights to the antlers.
The bottom-right image includes the backlight, which highlights the back end of the model and casts a halo
around the edges if viewed from the front.

FIGURE 20.2
An elk model rendered using default lighting, a single key light, two secondary lights, and a backlight

The final type of light to keep in mind is ambient light. Ambient light is not from a direct source but is cre-
ated by light that is deflected off walls and objects. It provides overall lighting to the entire scene and keeps
shadows from becoming completely black. Global Lighting (including Ambient light) is set in the
Environment panel.
Shadows
Shadows are the areas behind an object where the light is obscured. Max supports several types of shadows,
including Area Shadows, Shadow Maps, and Raytraced Shadows.
Area Shadows create shadows based on an area that casts a light. It doesn’t require lots of memory and
results in a soft shadow that is created from multiple light rays that blur the shadows. Shadow maps are
actual bitmaps that the renderer produces and combines with the finished scene to produce an image.
These maps can have different resolutions, but higher resolutions require more memory. Shadow maps typ-
ically create fairly realistic, softer shadows, but they don’t support transparency.
Max calculates raytraced shadows by following the path of every light ray striking a scene. This process
takes a significant amount of processing cycles but can produce very accurate, hard-edged shadows.
Raytracing enables you to create shadows for objects that shadow maps can’t, such as transparent glass. The
Shadows drop-down list also includes an option called Advanced Raytraced Shadows, which uses memory
more efficiently than the standard Raytraced Shadows. Another option is the mental ray Shadow Map.

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