[vtkusers] Bug in depth ordering whilst rendering

[Peter Clifton]

On Wed, 2007-11-28 at 09:40 -0500, Jeff Lee wrote:
> If these artifact are independent of whether you have opacity set or
> not, it is probably a depth-buffering issue.  What happens when you
> setenv GL_DEPTH_BITS 32 and relaunch your app?
> -J

Converting to bash...

GL_DEPTH_BITS=32 ipython -wthread vtk_test.py 

(Where vtk_test.py is the very short "Simple Example" at:
http://scipy.org/Cookbook/MayaVi/mlab

Its still bad from certain camera angles.

AHA... turning on MESA_DEBUG=1..

Mesa warning: glEnable(GL_DEPTH_TEST) but no depth buffer

It does seem like we have a guilty suspect. I'll bug the Intel driver
guys to see if there _should_ be a depth buffer.

Thanks for the help... I'm sure I didn't see that message last time I
tried with MESA_DEBUG=1, perhaps the distro version wasn't built with
all debugging enabled. I've since built it myself from git HEAD.

Is a depth buffer expected on GL Hardware??

Best wishes,

-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)