Whats the difference between displacement maps and bump maps?
Displacement maps actually change geometric position at the per-vertex or per-fragment level. This means that object silhouettes actually change, based on the displacement map. In contrast, bump maps keep the geometric position the same, but perturb the normal. Therefore, bump mapping is useful only when lighting changes or when the viewpoint moves (in the case of specular highlights). Given a static screenshot, it is often difficult to tell if a surface is bump-mapped or displaced. I’ve set up my Direct3D texture stage states to perform an operation, but it’s not working! What’s wrong? The caps report 8 stages are supported and I’m only using 4. Although 8 stages may be reported by the caps, that doesn’t mean that all combinations of operations are supported. D3D8 added the ValidateDevice function to help with this. So before you start your game, you should run through the techniques you would like to use, and test them with ValidateDevice. To support older cards like GeForce4 MX and
