Hi Christian, There is only one ballScale parameter per model. So this is not a bug, it is just applied to the whole model even when you specify only a part of the model, as per the help page: "The ballScale parameter applies to an entire atomic model even if only part of the model is specified." <https://rbvi.ucsf.edu/chimerax/docs/user/commands/size.html> However, you can change the individual ball sizes by changing the individual VDW radii of the atoms (ball radius = ballScale X VDW radius) which is also done with the "size" command (or "setattr"). I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Resource for Biocomputing, Visualization, and Informatics Department of Pharmaceutical Chemistry University of California, San Francisco

On Feb 19, 2024, at 4:51 AM, Christian Tüting via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:

Dear ChimeraX dev team, I found an issue with the styling of the ball&stick representation in ChimeraX.

Here is a code snipplet to see the issue:

# load a random model and show two residues open 7ott hide cartoons show #1:283-284 atoms style #1:283-284 ball

# this worked size #1:283 stickRadius 0.1 size #1:284 stickRadius 0.25

# this does not work size #1:283 ballScale 0.4 size #1:284 ballScale 0.1

The ballScale value is not applied on the selection like the stickRadius, but is always applied globally.

I am running the latest daily build (1.8.dev202402162121 (2024-02-16 21:21:18 UTC)) on MacOS. Best Christian