intersections of planes in geomview

[munzner]

There is currently no trivial way to do this. It's the kind of thing
you could write a module for. There's some code that would make
writing such a module easier: the core of Daeron's Ginsu program is a
general clip program that can be called directly. I think it takes a
plane and a geom as input and returns the clipped geom. You can talk
to him directly about it.