From: John Stone (
Date: Thu Sep 02 2021 - 08:43:49 CDT

Have you checked to ensure that you're not running your system out of
memory? Do you have a conventional OpenGL rendering of the scene in
question for comparison? When you render the scene to an external file,
how large is the scene file? I notice that in the output you included
below, there's no console output indicating that spatial acceleration grid
structures were built, despite the fact that you have the +V flag enabled.
That is one of the reasons I'm wondering about the memory exhaustion
issue. Another possibility is a runaway grid build of some sort, but
I haven't seen a problem like that for a very long time, so the odds
are somewhat against it.

  John Stone

On Thu, Sep 02, 2021 at 12:29:11PM +0000, Jason Hlozek wrote:
> Hi
> I'm trying to render an overlaid view of multiple ligands in the same
> protein pocket (i.e. a very busy scene).
> If I go above 2-3 protein/ligand pairs in the scene, then VMD still writes
> the scene file and calls Tachyon as usual but after a few seconds of
> processing, instead of proceeding to the completion % bar, Tachyon instead
> just ends with VMD saying the render is complete even though it didn't
> run. The same thing happens if I try to call tachyon from the command
> line:
> "C:\Program Files (x86)\University of Illinois\VMD> .\tachyon_WIN32.exe +V
> "C:\Users\user-pc\AppData\Local\VirtualStore\Program Files
> (x86)\University of Illinois\VMD\mmpl3_overlay_test"
> Tachyon Parallel/Multiprocessor Ray Tracer Version 0.99.1
> Copyright 1994-2014, John E. Stone <>
> ------------------------------------------------------------
> C:\Program Files (x86)\University of Illinois\VMD>"
> I thought it might be timing out and tried increasing the windows Timeout
> Detection and Recovery (TDR) registry variables as well as disabling them
> but it made no difference.
> Any suggestions please?
> Kind regards
> Jason

NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801           Phone: 217-244-3349