From: John Stone (
Date: Mon Apr 03 2017 - 09:45:35 CDT

  Only the _external_ CPU Tachyon renderer can write the scene geometry to a
".dat" file. All of the "internal" Tachyon variants write images only, and
they do not write (nor can they read) scene geometry to/from .dat files.
You would normally use it like this (just one example):
  render TachyonLOptiXInternal /some/directory/my/image.tga

The OptiX-based GPU-accelerated variant of Tachyon is not (presently)
included in the standalone binary, so for the time being you cannot run
it except from within VMD itself. That being said, you can of course
run VMD in text mode for long batch mode renderings. This is in fact how
we use VMD to render long movies in parallel on supercomputers, using the
MPI-enabled versions of VMD.

  John Stone

On Mon, Apr 03, 2017 at 09:16:44AM +0000, Amit Gupta wrote:
> Hi,
> render list helped. Now i can render images using tk console command 'render TachyonLoptiXInternal filename'. However when i try getting .dat file it gives error:
> Info) Rendering current scene to 'abc.dat' ...
> ERROR) Unrecognized image file extension, writing Targa file.
> while :
> 'render Tachyon filename.dat' works perfectly.
> Also can i not invoke OptiX rendering through shell? as in directly using /usr/local/lib/vmd/tachyon_LINUXAMD64 binary
> ________________________________________
> From: <> on behalf of Andrea Spitaleri <>
> Sent: Monday, April 3, 2017 1:06:37 PM
> To:
> Subject: Re: vmd-l: Accessing tachyon optix from commandline and dat file generation
> Hi,
> in tk console try render list. It will give you back a list of render
> available methods. Have look to here too:
> best
> and
> On 03/04/2017 08:41, Amit Gupta wrote:
> > 1. I want to get .dat file to generate images of arbitrary resolution. But in VMD (Linux) I can only see option for that in normal tachyon. i.e. TachyonL-Optix gives images directly. is there anyway to use Tachyon with GPU to generate .dat files? Using OSPray? I have seen VMD site claiming it can run on massively parallel supercomputers, is that done using only mpi?
> >
> > 2. How to tell tachyon to use optix renderer for generating images using GPU from command line? i.e. what is GPU equivalent of tachyon -res xxx yyy ?
> >
> --
> Andrea Spitaleri PhD
> Computational mOdelling of NanosCalE and bioPhysical sysTems - CONCEPT Lab
> Via Morego 30, 16163 - Genova, Italy
> cell: +39 3485188790

NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
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