From: Axel Kohlmeyer (
Date: Sun Dec 04 2011 - 23:19:35 CST

On Sun, Dec 4, 2011 at 10:35 PM, David Cohen-Tanugi <> wrote:
> Dear All,

dear david,

> What are the most effective ways of rendering high-quality and long movies
> from VMD trajectories?
> I have been using VMD to visualize long (1000+ frames) trajectories of
> molecular dynamics simulations from LAMMPS, and I haven't yet found an
> efficient way to render these trajectories into high-quality videos. My
> Macbook Pro is quick enough for most purposes but at 2-3 minutes per frame
> in Tachyon Internal with ambient occlusion, it seems much more logical to
> export the job to a parallel cluster on many nodes.

sure, and it is a fairly straightforward thing to do.

> In that context, what is the most straightforward and efficient way to
> render and encode a very long, high-quality movie from a VMD session?
> Strategies that leverage parallelized cluster computing would be greatly
> appreciated!

the general strategy would be to do visualization, rendering, and
movie generation as separate steps. for the visualization, you
can create input files for Tachyon from within VMD through a
loop construct. those can then be transferred to a cluster (or
you can use a previously saved state and generate the render
inputs directly on the cluster) and then rendered into individual
pictures in batch mode. Tachyon can be compiled for threading
or MPI parallelization on top of that you can parallelize over the
individual input scripts (but it is usually more effective to bundle
multiple inputs into a single submit script). if you are limited by
disk space, you may want to compile Tachyon with jpeg support
or convert the default TGA format files into high-quality (85-95)
jpeg files. the final step would be to convert the individual
image frames into an mpeg/quicktime/divx/avi/mp4/whatever
format movie with your favorite tool.

this will require some custom scripting, but a lot of the required
script code is either straightforward to write from scratch or can
be adapted from the vmd movie maker plugin.

for the quality setting, you should take into account the image
and quality loss through the video compression (depending on
the selected video data rate), which benefits from avoiding hard
contrasts, "pure" colors (especially red) and smoothing/antialiasing.


> Many thanks,
> David
> David Cohen-Tanugi | Ph.D. Candidate | Jeffrey C. Grossman Group |
> Massachusetts Institute of Technology | Department of Materials Science &
> Engineering | 609-902-6850 | |

Dr. Axel Kohlmeyer
College of Science and Technology
Temple University, Philadelphia PA, USA.