[chimerax-users] volume zone - unexpected behavior when newMap false

[Elaine Meng]

Hi Alexis,
Probably I need to word the explanation more clearly, but as I understand it the invert option of “volume zone” only applies to newMap true.  Invert specifies whether values in the new map should be zero within the cutoff, or zero beyond the cutoff.

<http://rbvi.ucsf.edu/chimerax/docs/user/commands/volume.html#zone>

When newMap is false, there is no new map within which to set zero values, and instead the surface display is restricted to within the cutoff.  Although your expectation is reasonable that “invert” might also work in that case (restrict surface display to beyond the cutoff), it hasn’t been implemented.  When newMap is false, it uses the “surface zone” capability, which doesn’t have an invert option.

<http://rbvi.ucsf.edu/chimerax/docs/user/commands/surface.html#zone>

So at least for now, “newMap true” if you want the inverted result of density display outside the zone.
Best,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Feb 8, 2019, at 8:44 PM, Alexis Rohou <a.rohou at gmail.com> wrote:
> 
> Hello,
> I've been playing with volume zone and having good fun, but...
> 
> I've noticed that if I set newMap to false, then the invert option is
> ignored (behavior is as though invert is false, even when I specify
> invert true).
> 
> When newMap is set to true, or not set at all, the invert option has the
> effect I expected from reading the documentation.
> 
> Am I missing something? Hopefully description above is unambiguous but
> let me know if you need step-by-step.
> Cheers,
> Alexis