Most end users believe top-class games use very detailed geometry to render the lush scenarios and characters seen onscreen. Although sometimes that's actually true, there are other, more powerful weapons in the game developer's toolbox. Geometry has a very high cost, and most of the time the same amount of detail can be supplied not by means of more vertices, but with clever use of materials and textures. Sharp, crisp textures convey lots of information and are, in the end, responsible for most of the believability of the scenarios.
In the previous chapter, we discussed how lighting goes a long way in providing realism to a scene. However, well-lit surfaces are just one part of the equation. We need actual materials, bricks, stones, and mortar. Characters need eyes and skin, and many other details that are usually conveyed with texture mapping techniques. This is what this chapter is all about. However, this chapter should be read along with the previous one because many techniques are common, and others are simply steps in a continuous progression. Both chapters, taken as a whole, will help you understand how we can set the look and feel of our graphics engines.