[chimerax-users] Define axis along z?

Hi, For symmetric EM volumes, it would be useful to be able to easily create an axis corresponding to the molecular symmetry axis - generally coincident with a vector parallel to the Z-axis of the box, directly through the center. Is there an easy way to create such an axis in ChimeraX for an arbitrary map? It would be useful to have such an axis in order to rotate a volume around the molecular symmetry axis, even in the absence of a model (this is fairly easy to do if a model is present using define axis). This might be a useful generic extension to "define axis", if there isn't already an easy way to do so. Cheers Oli