1 Lighting computation is handled in eye space(需要根据眼睛的位置来计算镜面发射值有多少进入眼睛), hence, when using GLSL (GPU) to do so, we need to transform vertex from local space to eye space in vertex processor.
2 vec4 ftransform(): 将vertex从eye space转到clip space
3 why procedural texture (generated from the program not by reading from the image) is infinite?
Because we could draw a 3D scene in the computer, this scene is infinite. We see it from a certain direction then use this view (frame) (就是用此时看到的情景作为texture) as texture. Hence, the texture is like the scene we view in natural life, it is infiinite.
4 bump mapping 示例
5 Refraction (折射) 示例