I was able to find the python script for the command, thanks to the online documentation.

I’ll try to work something out of this.

Shubham

Sent from Mail for Windows

From: Elaine Meng
Sent: Wednesday, June 29, 2022 19:34
To: Shubham Devesh Ramgoolam
Cc: chimerax-users@cgl.ucsf.edu
Subject: Re: [chimerax-users] Aligning a trajectory to its first frame

Hi Shubham,
The "coordset" command for playing back trajectories and the "coordset slider" command for showing a slider interface both have a "holdSteady" option for specifying which atoms to fit between frames:

<https://rbvi.ucsf.edu/chimerax/docs/user/commands/coordset.html>
<https://rbvi.ucsf.edu/chimerax/docs/user/commands/coordset.html#slider>

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                      
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco


> On Jun 29, 2022, at 12:30 AM, Shubham Devesh Ramgoolam via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
>
> Hi all,
> I hope you are doing well.
> Is there a way to align all the frames of a trajectory to its first frame for the purpose of visualization?
> I’m trying to visualize a residue pair in a trajectory and I have done the following:
> select both residues; view sel; play the movie.
> The issue here is that the position of the pair changes (the pair rotates across the screen) with the frame.  
> Regards,
> Shubham Ramgoolam