POV-Ray : Newsgroups : povray.advanced-users : I really really want n-sided bezier patches... : Re: I really really want n-sided bezier patches... Server Time
5 Oct 2024 08:04:24 EDT (-0400)
  Re: I really really want n-sided bezier patches...  
From: Rune
Date: 23 Aug 2002 12:12:38
Message: <3d665ef6$1@news.povray.org>
Micha Riser wrote:
> In uv-space the triangles are ditributed even.
> If you make patch that has the shape of an isosceles,
> rectangulare triangle then you will see that all
> triangles are of (nearly) same size (because uv-space
> has the same distances as realspace).

But by this, you are saying that the w value is not like the u and v
values. I don't think this fits with the ideology behind the 3-sided
bezier patch. There is not supposed to be any difference between the
three sides.

> It just depends on the shape of the triangle how
> equally the triangles are sized. I could tweak it so
> that they were equally-sized on equilateral patch size..

As I wrote, when you change the epsilon1 value to 1, then the
distribution is even for a equilateral triangle and there is no
difference between the three sides. I'm pretty convinced that this is
how it's actually supposed to work, and I don't think it's a random
"tweak" but rather a correction.

> The program works as expected.

Now it does. :)

> To solve your problem one probably has to add support
> for arbitrary edge points in uv-space for the triangle.

The uneven distribution and the UV mapping are two completely different
issues. The UV mapping never was a problem, and as I said earlier, I do
indeed intent to add support for custom UV vectors for the UV mapping.
The uneven distribution was the actual problem, but I found the solution
for that (changing the epsilon) so now there's no problem at all...

> Just a plain simple regulare space.

There is a white space in the messages I send. If it's not there when
they arrive, then Outlook Express must somehow remove them. :(

Rune
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