[PyMOL] Roving detail and Roving density

[Craig Smith]

Dear all,

I was looking at the demos in pymol (wizard --> demo) and saw  
interesting features called roving detail and roving density.  I  
looked in the manual on how to do this feature but couldn't find it.   
Could anyone point me in the right direction or show me how to  
interactively display electron density as I move through my structure.

Thanks

Craig