Hi Thu, There is a "crop" mouse mode to crop interactively. You can assign it to right mouse using the icon in the Right Mouse tab of the toolbar (looks like a cube with an arrow next to it), or to some other button using the "mousemode" command. See: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/mousemodes.html> <https://rbvi.ucsf.edu/chimerax/docs/user/commands/ui.html#mousemode> Also when you use that mouse mode, ChimeraX shows the corresponding "volume" command in the Log with "region" details in case you need that for some other command like "save" <https://rbvi.ucsf.edu/chimerax/docs/user/commands/save.html#map> 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 Jan 16, 2024, at 12:53 PM, Thu Nguyen via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:

Good afternoon, I am looking for several methods to crop out a map region from a larger density map. So far I know the command "volume region" but to use the command I need to know in advance the grid indices of the region I want to crop. Are there any more convenient methods to crop out a map region (maybe using mouse to directly drag a region from the volume map)? Thank you very much.

Best regards, Thu