From: Axel Kohlmeyer (
Date: Wed Jul 17 2013 - 23:04:53 CDT

On Thu, Jul 18, 2013 at 5:08 AM, yi <> wrote:
> Hi, Dear VMD users:
> I want to use VMD to show the atoms in the constrained region like x>10 and x<20, firstly, set sel [atomselect top "type 3 and x>10 and x<20"], then Select the "Update selection every frame" button, but the update selection every
> frame doesn’t work. VMD just applied the constraint to "those atoms" located in this region at frame 0 and Those atoms move far away from this region during time, and the attached were structures at frame 0 and frame 200. Is it possible to apply a constraint to a region in all frames rather than the atoms?

you are describing two things that are related only by the fact that
they use the same facility internally. in the first step, you define a
selection object in the script console that can be used for analysis,
and then you apply the "update" option to a display selection. how
*can* you expect that the second will have an effect on the first?
this is not a VMD problem but a case of PEBCAC. if you do it
correctly, it will work.


> frame 0 frame 200

Dr. Axel Kohlmeyer
International Centre for Theoretical Physics, Trieste. Italy.