'invert' option of 'volume zone' requires 'newMap true'

[Eric Pettersen]

I would like to invert the display on an existing map for the Phenix Fit Ligand tool.

[Tom Goddard]

I'm not sure how hard it is to show only the far part of the surface. The volume zone command does two quite different things depending on whether newMap is true or false. If newMap is true it creates a copy of the map with values at some grid points set to zero, it does no hiding of surface. If newMap is false it simply hides part of the surface using the surface zone command. The surface zone command does not allow inverting shown/hidden parts of the surface, there is no invert option of surface zone. But there is a "surface invert" command that does this. It seems like it would be easy to add this to surface zone and volume zone with newMap false. But it needs to auto-update as the surface changes (volume threshold change), and save that setting in thresholds.

If you are still at the stage of testing whether hiding the map near the protein is worth adding to Fit Ligand, you could use surface zone and surface invert to see what it looks like in real use cases. I'd like to avoid implementing the invert option unless it is going to be used. It is a very rare use that I cannot recall anyone asking for outside your use.

[Tom Goddard]

The volume zone invert option is documented to require newMap true.