Hi there we want to load a model from 3DMax and render them with OpenGL. Here's my question: http://www.opengl.org/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic&f=2&t=020671 After some replies, i understood that the problem refers to the normals generated by 3DMAX. My colleague has used from the Flip normals instead of Unify normals. What should he do to generate the correct normals? Note that he should export the max models to the 3ds file format. -Ehsan-