Subject:
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Re: Sphere tesselation
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Newsgroups:
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lugnet.cad.dev
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Date:
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Tue, 12 Sep 2000 21:30:43 GMT
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Viewed:
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971 times
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In lugnet.cad.dev, Travis Cobbs writes:
> "Steve Bliss" <steve.bliss@home.com> wrote in message
> news:f5csrssq9rkotteig88soujitik82bkj48@4ax.com...
> > In lugnet.cad.dev, Travis Cobbs wrote:
>
> Thanks for the info. The next thing I'm going to try will be similar, but
> iterative instead of recursive in order to allow for a set of points that's
> not a power of 2 (which may or may not work). You had to make your starting
> case overly complicated in order to handle 12, as explained below.
I wonder if it's possible to push the (initial?) vertices toward the center.
I was playing around with fractaling from a simplest case (1 triangle in the
mesh). I noticed the center area was made up of one type of triangle (nearly
equilateral), but the areas near the corners were flattened (because the
angles at the vertices of the surface are actually 90 degrees, not 60).
> > I'm not sure why I started with the 10-mesh that I did. It would have • been
> > a lot less code to start with just the 3 points on the axes. Maybe I
> > wanted to have that center-point?
>
> You had to, because 12 (the number of subdivisions along each edge) is not a
> power of two, and since you could only cut the edge of each triangle in half
> (subdividing it into 4 new triangles), you had to start with nine triangles
> which could then be subdivided twice each to yield 9*n^4 total triangles,
> where n is the number of subdivisions of those triangles, or 9*2^4=144
> triangles.
Doh! Of course. I was so busy trying to figure what my code did (the 6-month
rule of undocumented routines), I didn't have any spare brain cells. Yeah,
that's it.
Steve
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Message is in Reply To:
 | | Re: Sphere tesselation
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| "Steve Bliss" <steve.bliss@home.com> wrote in message news:f5csrssq9rkotte...4ax.com... (...) 5 (...) points (...) Thanks for the info. The next thing I'm going to try will be similar, but iterative instead of recursive in order to allow for a set (...) (24 years ago, 12-Sep-00, to lugnet.cad.dev)
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