I must be doing something _really_ stupid, but why I can't
> draw even a simple tetrahedron with OpenGL? One of the faces > does not show :-/
Is there any magic word that I must utter before it works?
I have two guesses:
1) Could OpenGL be culling the back-facing polygons? Try changing GL_FRONT to GL_FRONT_AND_BACK in various places, and see if that fixes it.
2) How are you drawing the tetrahedron? Are you using GL_TRIANGLES, or more complicated approaches like GL_TRIANGLE_STRIP or GL_TRIANGLE_FAN? If it's one of the latter two, you may be defining your points in the wrong order, which could either cause some triangles not to draw at all, or to flip the normal on one or more of the triangles, so they look like back-facing polygons (see (1)). ______________________________________________________________________ Steve Sloan ......... Huntsville, Alabama =========> [EMAIL PROTECTED] Brin-L list pages .............................. http://www.brin-l.org Science Fiction-themed online store ..... http://www.sloan3d.com/store Chmeee's 3D Objects .................... http://www.sloan3d.com/chmeee 3D and Drawing Galleries .................. http://www.sloansteady.com Software ................ Science Fiction, Science, and Computer Links Science fiction scans ......................... http://www.sloan3d.com
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