And I'll take the opportunity to justify the use of greyscale modes in the future. The Theory Behind Bump Mapping Bump mapping is a technique that makes a flat surface look like it has small bumps on it. Most of you are probably familiar with this technique since it has been quite popular over the past few months. Most 3D games will implement it in the near future. The main idea is that for each texture you also store a corresponding bump map.
Some people use a greyscale version of the texture as a bump map.
The bump map can be considered as a height map, which stores the altitude of each pixel. Of course in the case of a bump map, this altitude is really small. Given this data, we can compute how much light is actually hitting this part of the surface, and shade it. There are various different lighting techniques to determine how to shade this surface, one of which was invented by M. Phong. This is my personal favourite since it looks really good.