Implement Rotating Wall


I wondered if it was possible to rotate a wall with respect to an axis of rotation? I am attempting to use it for granular simulations.

I see that under the fix wall/gran command there are options for shear and wiggle, but not rotate? I understand that you can rotate a group of atoms, but this wasn’t the solution I was looking for. Is there a way to do this in the current release?



Hmm. I thought we used to have that option with fix wall/gran,
but I don't see it, at least for the zcylinder case. It wouldn't
be hard to add as an extra option similar to shear or wiggle.

More generally, a better way to do this would be to add
a fix wall/region/gran command, similar to the other fix wall/region.
This is b/c regions can rotate. Then you could have a wall
that was a (somewhat) arbitrary boundary and rotate it.
But this would require more coding to get/store the wall/particle
interactions correctly for granular interactions (shear terms, etc).
But it should be do-able.