Hi, This is the first time that I post the question here. Please point me a direction for the question below. Thanks in advance! I'm trying to do dot3 bump mapping using OpenGL, where the multi-texturing function is used: glMultiTexCoord2fARB(GLenum texUnit, TYPE coords) At the same time, I need to tesselate the textured polygon to render ploygons with holes inside. In this case, I need to use: gluTessVertex(GLUtesselator* tessobj, GLdouble coords[3], void * vertex_data) However, I can't find a way to do both together. I can't find a way to fit the glMultiTexCoord2fARB(...) function in the GL tesselation routine and vice versa. Anyone had the similar problem before or has the ideas to get around it? I have an urgent dealine to meet and must sort this out soon. Any comments will be really appreciated. Many thanks, Chen