VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed Jun 10 2009 - 07:24:05 CDT

Rob,
  At present, you can only load a volumetric data object for all
timesteps. For a subsequent version of VMD I may enable loading
these for a trajectory, but to make that feasible, several parts
of the VMD volume rendering code need to be GPU-accelerated so that
animation of such datasets becomes usable. For now, you
could start with a plugin that loads only volumetric maps from the
last timestep. You might also consider talking to Axel and Jan
about projecting onto GTOs and providing the QM data to VMD via
the QM plugin APIs. If you could do that, it would use far less memory
than storing the volumetric grids for the properties of interest.
We expect to add several new QM related representations in the
next version that would likely be of interest to you.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Wed, Jun 10, 2009 at 01:11:34AM -0700, Rob wrote:
>
>
> Hi,
>
> I'm writing a plugin for Abinit.
>
> I can read sequential structure geometry files, so that I can
> see the atoms move during a structure relaxation, for example.
>
> Each relaxation step also comes with a charge density distribution
> as volumetric data; can I read this also as frames/timesteps?
>
> I'm writing the plugin right now and I see that the "read_next_timestep"
> function is repeatedly called until it returns MOLFILE_EOF.
> However, the "read_volumetric_data" is called only once during this
> procedure.
> Hence, I can have a sequence of atom positions as frames, but only
> one volumetric data......
>
> Or am I doing something wrong?
>
> Thanks,
> Rob.
>
>
> 

-- 
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