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Re: Tessellate Question--fewest convex polys [message #29250 is a reply to message #29244]

Fri, 08 February 2002 08:44

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Noname (parrhasius@altavista.com) writes:

> What's the best way to tessellate a polygon so that the resulting
> connectivity array contains the _fewest_ number of convex polygons instead
> of every single triangle? I don't want to cut up shapes like squares and
> octagons, only shapes with concavities or holes like lima beans and donuts.
> IDLgrTESSELLATOR always tessellates polygons into triangles, as I understand
> it; squares become 2 triangles, octagons become 6 triangles, etc...
>
> Using UNIQ and maybe MESH_MERGE I can get what I want by playing around with
> such a connectivity array of triangles, but as I am completely new to this I
> wonder if IDL already has this functionality or if this is a common and
> proven algorithm--or if I am just missing something obvious (most likely).
> Incidentally, what is the name for this type of tessellation? I know I've
> seen it implemented before in things like 3D video game level designers.
> For now I'd be happy with something that just worked in 2D.

I think what you are looking for is MESH_DECIMATE.

Cheers,

David
--
David W. Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438, E-mail: david@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155

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[Message index]

		Re: Tessellate Question--fewest convex polys By: karl_schultz on Fri, 08 February 2002 15:11
		Re: Tessellate Question--fewest convex polys By: Pavel A. Romashkin on Fri, 08 February 2002 10:39
		Re: Tessellate Question--fewest convex polys By: David Fanning on Fri, 08 February 2002 10:17
		Re: Tessellate Question--fewest convex polys By: Noname[1] on Fri, 08 February 2002 08:57
		Re: Tessellate Question--fewest convex polys By: David Fanning on Fri, 08 February 2002 08:44
		Re: Tessellate Question--fewest convex polys By: Mark Hadfield on Sun, 10 February 2002 13:15

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