From: Axel Kohlmeyer (
Date: Thu Feb 05 2009 - 17:23:40 CST

On Fri, 6 Feb 2009, Suman Chakrabarty wrote:

SC> Hi,


SC> I was trying to use the "Adding a Progress Bar for the Elapsed Time"
SC> tutorial of Axel
SC> (
SC> ) and it was awesome! :)

gee, thanks. ;-)

SC> But a problem occured when I tried to create a movie out of it. It seems
SC> that only the "snapshot" rendering method will keep the time bar with
SC> every detail. Using "Tachyon" I found the tick labels and the texts are

yep. this is a know issue, that is non-trivial to solve in
a general way. the export functions to various renderers
can only export a subset of what the opengl display is showing.

john will probably comment on that, and i am certain that he
would not mind, if somebody would want to spend some time on
actually implementing this. ;)

SC> not showing up in the movie, while the bar is working fine. Using
SC> "Povray" I found the bar is not there at all!
SC> I would like to know how to keep the bar visible in the movie while
SC> better rendering methods like "Tachyon" or "Povray" are being used.

they should show, but perhaps you have to adjust you camera settings.
particularly with povray, some adjustments need to be made.

due to the distoritions and artefacts from the compression algorithms,
it is usually not worth spending too much effort into the rendering,
and a recent graphics card with proper OpenGL/GLSL support will produce
high enough quality images even from "snapshot" for movies. for single
frames, you can always loard the rendered image into an pixmap editing
tool, e.g. gimp, photoshop and insert the missing labels.

SC> On a side note, any hint on how do I show the value of the current time
SC> as plain text (changing with the movie obviously) like "1000 ps"? Also,

you have to modify the scripting. check out the graphics commands.
with [format "Time: %f ps" $timestepvariable] you can produce
a proper formatted text.

SC> how do I change the format (bold, font size etc) of the text?

again, this would require some (complicated) programming
and is not (yet) implemented. the list of wishes for features
in VMD is long... (i have a bunch of entries in there as well. ;-)


SC> Thanks and regards,
SC> Suman Chakrabarty.

Axel Kohlmeyer
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
If you make something idiot-proof, the universe creates a better idiot.