[gl2ps] Re: Wierd problem with gl2ps under Mac OS X

[Christophe Geuzaine]

Prabhu Ramachandran wrote:
> Hi Christophe,
> 
> I sent in a message yesterday to gl2ps at geuz.org but apparently the
> message has not made it through.  So here is a re-send with some extra
> information.
> 
> I think I have found a bug in gl2ps on Mac OS X.  I have no idea where
> it occurs though.  One MayaVi user (Konrad Hinsen) was generating some
> figures via VTK->gl2ps and found that the generated PS/EPS/PDF has
> *no* shading, all the triangles are unshaded. 

Yes, I have the same problem on my Mac: it must be a bug in Apple's
OpenGL implementation...

It might be worth it to send a bug report directly to Apple.


Christophe



> I don't have a Mac so I
> have been asking the user to mail me test output.  I am attaching two
> gzipped EPS figures, one was generated on Linux and the other on the
> Mac OS X.  The linux version renders correctly and generates shaded
> triangles in the EPS output, the Mac version has no shaded triangles
> and looks flat.  The PDF output is also similarly bad with no shading
> of the triangles.  Both figures were generated using GL2PS_BSP_SORT.
> I also asked for output without sorting and while it is slightly
> different it also has no shading for any of the triangles.  Here are
> the other options used:
> 
>  GL2PS_DRAW_BACKGROUND, GL2PS_SIMPLE_LINE_OFFSET, GL2PS_BEST_ROOT,
>  GL2PS_OCCLUSION_CULL
> 
> Platform: MacOS 10.3.2
> gcc version: 3.3  (from the Apple developer kit)
> 
> I also have the VTK configuration options but don't think they will
> matter too much.  If you need them I can give you those too.
> 
> The pictures were generated via a small VTK-Python script.  I don't
> have a pure OpenGL test program I can mail.  The script basically
> renders a sphere and uses gl2ps to generate the PS output.
> 
> If you need more information please do let me know.
> 
> Thanks!
> 
> prabhu
> 


-- 
Christophe A. Geuzaine
Applied and Computational Mathematics, Caltech
geuzaine at acm.caltech.edu - http://geuz.org