glm.h Nate Robins, 1997, 2000 nate@pobox.com, http://www.pobox.com/~nate Wavefront OBJ model file format reader/writer/manipulator. Includes routines for generating smooth normals with preservation of edges, welding redundant vertices & texture coor

改编自DirectX SDK中的SphereMap实例，经过优化，可以通过按"A"，"S"，"D"三个键改变Technique，实现逐顶点、逐像素的变化，特别适合研究D3DEffect