说明：  OpenGL纹理映射。近百页的详细讲解OpenGL纹理映射机制的PPT教程，其中包含多种高级纹理映射技术：凸凹纹理、位移纹理、RayTrace、环境映射、法线贴图、过程纹理等。
(OpenGL texture mapping. Nearly a hundred pages of PPT tutorials detailing the OpenGL texture mapping mechanism, which includes a variety of advanced texture mapping techniques: bump texture, displacement texture, RayTrace, environment mapping, normal map, process texture, etc.)