From: John Stone (
Date: Tue Nov 08 2005 - 10:55:57 CST

  If you're getting all black geometry, it sounds like there's a race
condition in the CAVE display device with your version of CAVElib.
Try restarting the program and see if it behaves this way every time or
if you get correct lighting some of the time. If you get correct lighting
some of the time, then there's indeed a race condition in the VMD per-wall
OpenGL initialization with the version of CAVElib you're using. The bad
news is I don't have a way to solve the problem for you since we don't have
a CAVE running here currently so I have no way to test. If you want to try
changing the CaveDisplayDevice.C startup etc to log the sequence of OpenGL
commands that are being executed, you'll probably find that some OpenGL
state isn't getting set properly in the slave renderer for one of the eyes.
Is your CAVE system an active stereo or passive stereo system? From your
description it sounds like a passive stereo system, but it would be helpful
to know what the display configuration is so I have some idea what the
mapping of renderers to projectors/walls is.

  John Stone

On Tue, Nov 08, 2005 at 05:44:39PM +0100, Bram Stolk wrote:
> Hi there,
> Another quick question:
> for my IRIX6 CAVE build, I see the following behaviour when
> using -dispdev cave:
> - Lines are visible in both L en R eye.
> - Polygons are visible in R eye only.
> It looks like that for the L eye, all polygons are black, because
> they do seem to obscure the line geometry for the L eye.
> Did anyone else see this?
> thx,
> Bram
> --
> Bram Stolk, VR Engineer SARA, Amsterdam. tel +31 20 592 3000
> "Windows is a 32-bit extension to a 16-bit graphical shell for an 8-bit
> operating system originally coded for a 4-bit microprocessor by a 2-bit
> company that can't stand 1 bit of competition."

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