PDA

View Full Version : normals with triangle_strip (very easy question)



dhoffman
05-02-2001, 01:28 PM
Hi, I understand that although normals are directed perp to the flat polygon surface, they are define at the points. So when defining something such as a triangle strip, or fan, or quad strip, or anything where different flat surfaces are sharing vertices, how do you properly define the normals? For example:
glBegin(GL_TRIANGLE_STRIP);
normal1
vertex1
vertex2
vertex3
normal2
vertex4
glEnd();

So you could get two connect traingles that are not on the same plane. But for the second triangle the normal is only correctly defined for one vertex. Is there some way to assign more than one normal to a vertex? Or what do I do here? Can I not use GL_TRINAGLE_STRIP?

DFrey
05-02-2001, 01:34 PM
Is there some way to assign more than one normal to a vertex?
No, you can not. The only solution is to split the mesh, and duplicate the vertex.