VMD-L Mailing List

From: Mauricio Carrillo Tripp (trippm_at_gmail.com)
Date: Wed Apr 06 2005 - 15:00:54 CDT

Actually, the movie maker is an editable script that vmd runs. You
could modify that
script to do what you need. Or work your way around it, but you might need
a simple script at some point (just to make things easier and faster). What
you need to know is that you need 30 frames (or snapshots) per second in
the final movie (mpeg). What the movie maker script does, is to generate a
lot of snapshots (each one slightly different from the one before, as to create
the effect of movement in the final movie file. Of course these 'frames' don't
have to be different from each other, they can be the same one duplicated
many times, and the effect this would do in the final movie file is that your
molecule would appear to be 'frozen'). The last thing the movie maker script
does is to merge all the snapshots into one file (with the correct format, mpeg
for example) using an external tool (ppmtompeg in linux). If you do this, tell
the movie maker script not to delete the files it creates on the menu options
so you can use them later. Make a snapshot of the first frame and duplicate it
as many times as you need (30 times per each second you want on the movie).
Name them sequentially, lets say you want 2 seconds, then you will need
60 files, named something-0001.ppm to something-0060.ppm (you also need
to rename the frames vmd creates so they start at something-0061.ppm to
whatever number of frames vmd made, if it initially made 180 frames, then
the last frame would be something-0240.ppm). Now edit the file vmd created
with extension .par (something.par), changing the input section to include
all your frames:
INPUT
something-*.ppm [0001-0240]
END_INPUT
Now run 'ppmtompeg something.par', that should give you a file
something.mpg where the first 2 seconds are a 'frozen' molecule and after that
it will start to move!

On Apr 6, 2005 11:03 AM, Palmer, Teresa <Teresa_Palmer_at_nrel.gov> wrote:
>
>
>
> I'm displaying a trajectory of an MD simulation to be viewed in Movie Maker.
> I want to initially view the simulation with the molecule fixed but then
> show the simulation of the rotating molecule at later stages. Is it possible
> to do this without using a script? 

-- 
Mauricio Carrillo Tripp, PhD
Department of Chemistry
Wabash College
trippm_at_wabash.edu
http://chem.acad.wabash.edu/~trippm