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25 Dec 2024 22:57:57 EST (-0500)
  Tesselating a 2D surface (Message 1 to 8 of 8)  
From: Martin Magnusson
Subject: Tesselating a 2D surface
Date: 18 Nov 1999 17:37:19
Message: <38347f9f@news.povray.org>
Does anyone know of a (good) algorithm to tesselate a 2D polygon?

At least I think tesselation is what I'm after - what I want to do is
distributing points evenly inside a polygon with a certain maximum distance
to each other (that is, tesselate(d) should fill the polygon with enogh
points so that no points are more separated by more than d distance), and
then make a triangular mesh out of it.

Any ideas?


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From: Ken
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 17:49:35
Message: <38348242.3056C3FA@pacbell.net>
Martin Magnusson wrote:
> 
> Does anyone know of a (good) algorithm to tesselate a 2D polygon?
> 
> At least I think tesselation is what I'm after - what I want to do is
> distributing points evenly inside a polygon with a certain maximum distance
> to each other (that is, tesselate(d) should fill the polygon with enogh
> points so that no points are more separated by more than d distance), and
> then make a triangular mesh out of it.
> 
> Any ideas?

You might find something useful at one of the sites listed here:
http://www.povray.org/links/3D_Resources/3D_solid_construction_methods/

-- 
Ken Tyler -  1200+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/


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From: Peter Popov
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 18:08:40
Message: <rYQ0OBVf7QYQALlBzAYLuRabU1h9@4ax.com>
On Thu, 18 Nov 1999 15:37:55 -0700, "Martin Magnusson"
<mar### [at] studentuuse> wrote:

>Does anyone know of a (good) algorithm to tesselate a 2D polygon?
>
>At least I think tesselation is what I'm after - what I want to do is
>distributing points evenly inside a polygon with a certain maximum distance
>to each other (that is, tesselate(d) should fill the polygon with enogh
>points so that no points are more separated by more than d distance), and
>then make a triangular mesh out of it.
>
>Any ideas?

Ideas, yes. Solution, no. That's how I usually proceed, anyway :)

Using baricentric coordinates you can place a number of points in the
polygon. Now set up a simple repulsive force among them and the edges
of the poly and either calculate a preset amount of "time" or until
the speed of all particles drops below a certain value. There *might*
be a procedural approach, and if there is, Ken will have most probably
found the link to it by the time I post this message. Oh well...


Peter Popov
ICQ: 15002700


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From: Martin Magnusson
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 18:29:23
Message: <38348bd3@news.povray.org>
>Using baricentric coordinates
Say what?

>Now set up a simple repulsive force among them and the edges
That sounds like a good approach. It might take some time with 10000 or so
points, but then again, any algorithm will probably have to take some time.


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From: Ken
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 18:33:54
Message: <38348CA5.69C96D5@pacbell.net>
Martin Magnusson wrote:
> 
> >Using baricentric coordinates
> Say what?

Barycentric \Bar`y*cen"tric\, a. [Gr. ? heavy + ? center.] Of or pertaining
to the center of gravity. 

-- 
Ken Tyler -  1200+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/


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From: Martin Magnusson
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 18:38:23
Message: <38348def@news.povray.org>
>> >Using baricentric coordinates
>> Say what?
>Barycentric \Bar`y*cen"tric\, a. [Gr. ? heavy + ? center.] Of or pertaining
>to the center of gravity.

Ah, thanks!


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From: Ken
Subject: Re: Tesselating a 2D surface
Date: 18 Nov 1999 18:44:57
Message: <38348F3F.DC27BA24@pacbell.net>
Martin Magnusson wrote:
> 
> Does anyone know of a (good) algorithm to tesselate a 2D polygon?
> 
> At least I think tesselation is what I'm after - what I want to do is
> distributing points evenly inside a polygon with a certain maximum distance
> to each other (that is, tesselate(d) should fill the polygon with enogh
> points so that no points are more separated by more than d distance), and
> then make a triangular mesh out of it.
> 
> Any ideas?

http://xfactor.wpi.edu/Works/DCubanski/mva93h/subsection3_3_2.html

-- 
Ken Tyler -  1200+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/


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From: Martin Magnusson
Subject: Re: Tesselating a 2D surface
Date: 19 Nov 1999 17:12:17
Message: <3835cb41@news.povray.org>
Thanks a lot for your help. I love you guys!


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