Re: [Mesa3d-users] GLU 1.2 tesselator bugs ?

[Stephen J B. <sj...@li...>]

On Wed, 14 Jun 2000, Olivier Michel wrote:

> I recently moved from Mesa-3.0 to Mesa-3.2 and I had to update the GLU
> tesselator from 1.0 to 1.2. Although I followed the guidelines explained
> in the Red Book, the results weren't good at all:
> Some faces were reversed (wong side) and I got many crashes in glu
> library (apparently memory leaks) when the vertices of a non-convex
> polygon didn't lie exactly in the same plane.
> 
> I could identify more precisely one bug:
> 
> The gluTessNormal is ignored for re-orienting vertices whereas it should
> be used (as described in the OpenGL Reference and User manuals). This
> makes some faces appear on the wrong side. I found a workaround for this
> bug by calling glCullFace(GL_FRONT) just before drawing a face for which
> the normal direction is negative (and should reverse the vertice order).
> But this is an ugly workaround (as often).
> 
> I am now trying to identify better the crash problems.
 
Have you tried the same code using the GLU from the SGI OpenGL Reference
Implementation?    It would certainly be interesting to discover if it
exhibits the same problem...and might give you a reasonable work-around
in the short term.

Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
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