problem with hidden surface removal

[mbp]

> I display it in Geomview and rotate it around, at certain
> orientations, the "back" of the object shows through.  In other words,
> there seems to be some problem with hidden surface removal.

Yes, this is a known bug, or rather incomplete implementation, in
the current version.  We're working on a new X windows version which
will fix this problem.  It should be available sometime this fall.

--Mark