Digital Lighting & Rendering, Second Edition

CHAPTER EIGHT: The Art and Science of Color 217

In 3D graphics, internal calculations are done in RGB because it is much

quicker and easier to simulate illumination of colored surfaces by colored

lights when using only three possible wavelengths of light (red, green, and

blue) instead of a continuous spectrum using many possible wavelengths.

When Light Color Meets Surface Color

There are two very different ways that colors are mixed during a rendering.

As shown at the beginning of this chapter, when different lights overlap,

their colors are added together. When colored light illuminates a colored sur-

face, however, the light color is multiplied with the surface color. For example,

if you make a surface orange {1,.28,.08}, it will refl ect 100 ...