Re: [Update REQ 6916]: polyhedra with holes in GeomView

[ajbg96r at ecs.soton.ac.uk]

Hi, Tamara

I can see now that my previous message was not clear.
However, you've guessed it right. What I want to display would be for example,
a cube with a through hole.

Is there any possibility that a future version of geomview would include
such a capability?

Thanks

munzner at cs.stanford.edu wrote:

> From: Tamara Munzner <munzner at cs.stanford.edu>
> Message-ID: <14348.49223.749943.951249 at weevil.Stanford.EDU>
> Date: Tue, 19 Oct 1999 12:02:31 -0700 (PDT)
> To: software@geom.umn.edu
> Subject: [ REQ 6916]: polyhedra with holes in GeomView
>
> > 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
>
> assign: munzner
> state: closed
>



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