VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Thu Jun 12 2003 - 10:11:43 CDT

Dear Dan,
  Sounds like you've found a bug in the implementation of stereo in the
OpenGL drivers on your machine. Can you email us the startup text that
VMD prints on your machine? i.e.:

Info) Multithreading available, 1 CPU detected.
Info) OpenGL renderer: ZFB, VIS
Info) Features: STENCIL MSAA(16) RN MDE MTX GAS
Info) Textures: 2-D (4096x4096), 3-D (512x512x512), Multitexture (4)
Info) Opening Spaceball on port: /dev/ttya

That will tell me something about what your machine's video driver is doing.
VMD is very demanding on the video card and the OpenGL driver, so its not
surprising that you may have found a bug in the implementation of stereo
on your PC. This is a big weak point with the Linux drivers that
are available presently, even the commercial ones such as XiG.

One thing you may wish to try would be to run one of the last test versions
of VMD 1.8.1 with the "VMDPREFERSTEREO" environment variable. Its possible
that the XiG drivers are having problems because VMD wants _both_ antialiasing
as well as stereo. The "VMDPREFERSTEREO" variable in the new versions gives
you a way to make less VMD slightly less agressive in its use of OpenGL
features, it only asks for stereo when that variable is set, so it avoids
some problems people have had with PC video cards and their drivers.

You may or may not experience the same behavior with other programs
since they are unlikely to use the same combination of OpenGL features
that VMD uses. VMD is far more demanding of the video drivers than
most apps are.

  John

On Thu, Jun 12, 2003 at 04:38:37PM +0300, Dr. Daniel James White PhD wrote:
> Hi all.
>
> In VMD 1.8 linux (Dec 2002) on redhat8.0
> with Xig summit Xserver for stereo
>
> I get double image for one eye with crystal eyes stereo
> with the stereo graphics enabler and emitter box from an ATI radeon
> 8500 64 mb
>
> is this a bug, is is it just me?
>
> Cheers
>
> Dan
>
>
> Dr. Daniel James White BSc. (Hons.) PhD
> Cell Biology
> Department of biological and environmental science
> PO Box 35
> University of Jyväskylä
> Jyväskylä FIN 40014
> Finland
> +358 (0)14 260 4183 (work)
> +358 (0)414740463 (mob)
>
> http://www.chalkie.org.uk
> dan_at_chalkie.org.uk
> white_at_cc.jyu.fi 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349              
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078