Why use Vertex Shaders?
If you use Vertex Shaders, you bypass the fixed-function pipeline or T&L pipeline. Why would you want to skip them? Because the hardware of a traditional T&L pipeline doesn’t support all of the popular vertex attribute calculations on its own, processing is often job shared between the geometry engine and the CPU. Sometimes, this leads to redundancy. There is also a lack of freedom. Many of the effects used in games look similar with the hard-wired T&L pipeline. The fixed-function pipeline doesn’t give the developer the freedom he need to develop unique and revolutionary graphical effects. The procedural model used with vertex shaders enables a more general syntax for specifying common operations. With the flexibility of the vertex shaders developers are able to perform operations including: • Procedural Geometry (cloth simulation, soap bubble [Isidoro/Gosslin]) • Advanced Vertex Blending for Skinning and Vertex Morphing (tweening) [Gosselin] • Texture Generation [Riddle/Zecha] • Advan
