[Closed REQ 6916]: polyhedra with holes in GeomView

[munzner at cs.stanford.edu]

> I am trying to use geomview to display polyhedra using the OFF format,
> but there seems to be
> provision for polyhedra with holes, that is some faces would consist of
> at least two polygons.
> 
> I wonder if there is some way to do it

I'm trying to interpret the above message. I think you mean "there
seems to be *no* provision for holes", right? But then you say "some
faces would consist of at least two polygons". Well, the latter should
work just fine. But presumably you actually have faces in some format
that actually supports polygons with a hole. Unfortunately, there's no
way to even specify that in a form that Geomview can understand. 

So I don't think I can help you. If it were just that it was a concave as
opposed to convex polygon, you could use the "concave" appearance
flag, that might work. (It's off by default for speed reasons.) It
works in the OpenGL version, although not in the raw X rendered. I'm
not sure about the Mesa version. You'd do that with

{ appearance { +concave } OFF .....}

But I think you have no choice but to do to the work of decomposing
them into multiple polygons with say a triangulating program. I'm sure 
there's such a program out there, you just have to find it. Start with 
http://www.geom.umn.edu/software/cglist/trap.html

Sorry,
Tamara