VMD-L Mailing List

From: Peter C. Lai (pcl_at_uab.edu)
Date: Wed Aug 08 2012 - 16:49:54 CDT

Woops last message got cut off.

You can use a combination of trace and "draw text" commands in VMD to have it
draw text on each frame. The following code updates the timeindex in ps on
each frame (where the trajectory is 4 ps per frame), starting from 0 ps.

proc enabletrace {} {
  global vmd_frame;
  trace variable vmd_frame([molinfo top]) w drawcounter
}

proc disabletrace {} {
  global vmd_frame;
  trace vdelete vmd_frame([molinfo top]) w drawcounter
}

proc drawcounter { name element op } {
  global vmd_frame;

  draw delete all
  # puts "callback!"
  draw color white
  set psperframe 4
  set psoffset 0
  set time [format "%d ps" [expr ($vmd_frame([molinfo top]) * $psperframe) + $psoffset]]
  draw text {70 40 80 } "$time"
}

However draw text only draws basically rudimentary OpenGL line objects so the
labels get clobbered if the scene is really busy.

Most of the time, I actually use ImageMagick to tag the time index on each
frame before using FFMpeg to make the movie (although mencoder works too!)
http://www.imagemagick.org/script/index.php

The following Bash script works on Linux or Mac on the ppm output from VMD's
moviemaker extension (I don't have it encode, only dump the frames).

The basic ImageMagick command to do this is:
convert -font font -fill white -pointsize 36 -draw 'text 700,950 "0 ps"' file.in file.out

Example In bash:

find . -name "*.ppm" | while read line
do ts=$(echo $line | awk -F . '{print $3}')
rt=$(expr $ts \* 4)
rt="${rt} ps"
echo $rt
convert -font helvetica -fill white -pointsize 36 -draw "text 725,950 '$rt'" $line foo.$ts.jpg
done

If you are manually dumping frames in a VMD script with render instead of the
using the moviemaker plugin then you can have ImageMagick work on the
imageformat you dumped to (TGA, BMP, etc.). This saves time because compared
to using the moviemaker plugin since you don't have to wait for vmd to run
pnmtools on each frame before going to postprocess.

On 2012-08-08 12:04:58PM -0500, Bryan Roessler wrote:
> Hello,
>
> I was wondering if it would be possible to have the option to superimpose
> the current frame number on the display? This would be really helpful for
> making movies that loop so the audience could follow the movement. Also, if
> you are still looking for a free BMP movie encoder, mencoder works great.
>
> For example: "C:\Program Files (x86)\Mencoder\mencoder.exe"
> mf://yourname*.bmp -mf fps=15:type=bmp -ovc lavc -lavcopts
> vcodec=wmv2:vbitrate=10000 -o yourname.wmv
>
> Thanks,
>
> Bryan 

-- 
==================================================================
Peter C. Lai			| University of Alabama-Birmingham
Programmer/Analyst		| KAUL 752A
Genetics, Div. of Research	| 705 South 20th Street
pcl_at_uab.edu			| Birmingham AL 35294-4461
(205) 690-0808			|
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