VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Sat Nov 01 2008 - 10:12:56 CDT

Hi,
  Axel's suggestion is the best approach at the moment, since there's
not presently an interface in VMD to store frame-specific graphics
objects. I could conceivably add such a feature, but it's very
rarely asked for, and in the few cases it is, the approach Axel is
mentioning can be made to work pretty well.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Fri, Oct 31, 2008 at 05:59:44PM -0400, Axel Kohlmeyer wrote:
> On Fri, 31 Oct 2008, Benjamin Bouvier wrote:
>
> BB> Rogan,
> BB>
> BB> Thanks for the link. Unfortunately, the tutorial confirms my initial idea of
> BB> using variable traces and manually redrawing the whole scene each time the
> BB> frame counter changes... In my case this is suboptimal, since it takes more
> BB> than a minute to compute the custom graphics for a single frame (using C++
>
> if you want to create an animation with vmd movie maker or equivalent,
> this concern does not matter. in the other case, you could just draw
> into multiple molecules and show only one of them using multimolanim.
>
> cheers,
> axel.
>
> BB> code). What I do now is to store the outputs of the C++ code (a Tcl script
> BB> per frame) and 'eval' the right one in conjunction with 'trace', which is
> BB> much better. Still, the scripts are long, and Tcl parsing does not come for
> BB> free... Worse: while viewing a trajectory, I might look at a given frame
> BB> several times, and each time the Tcl parsing has to be redone from
> BB> scratch...
> BB>
> BB> Processing all frames once and for all and storing the resulting low-level
> BB> primitives in some kind of display list (eg, as implemented by OpenGL) would
> BB> be much more efficient. I was wondering whether there was any way to do
> BB> that...
>
> multimolanim is a close to that as you can get. everything else
> would require additional low level programming.
>
> BB>
> BB> Cheers,
> BB>
> BB> On Fri, 31 Oct 2008 17:22:55 +0100, Rogan Carr <rogan_at_ks.uiuc.edu> wrote:
> BB>
> BB> >Hi Benjamin,
> BB> >
> BB> >You should check out the Images and Movies Tutorial. It has a section
> BB> >on drawing per-frame graphics, as well as tcl example code.
> BB> >
> BB> >http://www.ks.uiuc.edu/Training/Tutorials/
> BB> >
> BB> >Cheers,
> BB> >Rogan
> BB> >
> BB> >On Fri, 2008-10-31 at 16:46 +0100, Benjamin Bouvier wrote:
> BB> > >Hi all,
> BB> > >
> BB> > >I'd like to make a movie out of a set of custom representations that are
> BB> > >built using the 'graphics' low-level call.
> BB> > >
> BB> > >It seems, however, that 'graphics' calls affect all frames of a
> BB> > >trajectory
> BB> > >simultaneously rather than one at a time... Since the computation of the
> BB> > >representations (ie, the generation of the Tcl code that draws them) is
> BB> > >time-consuming, on-the-fly recalculation at each frame change is out of
> BB> > >the question. My initial idea would be to store the Tcl code for each
> BB> > >frame in a list or array, and have it execute at each frame change; not
> BB> > >very elegant, and also not very fast, since parsing the (rather lengthy)
> BB> > >Tcl code for each frame takes a couple of seconds...
> BB> > >
> BB> > >Any ideas?
> BB> > >
> BB> > >Cheers,
> BB> > >--
> BB> > >Benjamin
> BB> >
> BB>
> BB>
> BB>
> BB>
>
> --
> =======================================================================
> Axel Kohlmeyer akohlmey_at_cmm.chem.upenn.edu http://www.cmm.upenn.edu
> 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. 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
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Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078