http://gongziya.com/941/opengl%E8%AF%BB%E5%8F%96obj%E6%A8%A1%E5%9E%8B%E6%96%87%E4%BB%B6/comment-page-2/
http://www.cnblogs.com/kex1n/archive/2011/09/23/2186361.html