Today's games make extensive use of what is referred to as lightmap and vertex lighting. However, that will begin to change as game developers begin to take advantage of the GeForce 256's support for up to 8 real-time light sources.
Lighting comes in a variety of types such as light from the sun, indoor lighting, and spotlights.
Even objects such as mirrors and brass doorknobs reflect light. Adding multiple light sources, to create a more realistic scene, further adds to the complexity. As was eluded to earlier, rather than tracing the path of light beams in real-time, today's games typically use lightmaps which are images that change the color of an object making it appear as though a light is shining on it. As with transformations, lighting calculations are done via matrix manipulation, are more complex and are typically computing the distances and directions between light sources and objects. Lighting also takes advantage of the natural abilities of the human eye which are actually more sensitive to changes in brightness than it is to changes in color.