POV-Ray : Newsgroups : povray.binaries.images : Some rational Bezier patches Server Time
14 Mar 2025 05:05:58 EDT (-0400)
  Some rational Bezier patches (Message 1 to 2 of 2)  
From: Tor Olav Kristensen
Subject: Some rational Bezier patches
Date: 1 Mar 2025 18:55:00
Message: <web.67c39d103e30860b5ad2295d89db30a9@news.povray.org>
The attached image shows 15 bivariate rational Bezier patches wrapped around a
torus with a slightly smaller minor radius. The patches are triangle meshes.

The gaps between the patches are there because the patches are not created with
u and v going from 0.0 to 1.0, but from 0.04 to 0.96.

The size of the control grid for each patch is 3 in both the u-direction and the
v-direction, so each control grid consists of 9 points.

The makes the Bezier blending functions for each grid to be quadratic (in the
numerator and the denominator) in both the u-direction and the v-direction.

In this image the black stripes in the patches are made with pigments where an
object pattern controls the colors.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k


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Attachments:
Download 'test_rationalbezier_18.png' (704 KB)

Preview of image 'test_rationalbezier_18.png'
test_rationalbezier_18.png


 

From: Leroy
Subject: Re: Some rational Bezier patches
Date: 2 Mar 2025 13:50:00
Message: <web.67c4a7a1cd3c937d55e7d20f712fc00@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> The attached image shows 15 bivariate rational Bezier patches wrapped around a
> torus with a slightly smaller minor radius. The patches are triangle meshes.
>
> The gaps between the patches are there because the patches are not created with
> u and v going from 0.0 to 1.0, but from 0.04 to 0.96.
>
> The size of the control grid for each patch is 3 in both the u-direction and the
> v-direction, so each control grid consists of 9 points.
>
> The makes the Bezier blending functions for each grid to be quadratic (in the
> numerator and the denominator) in both the u-direction and the v-direction.
>
> In this image the black stripes in the patches are made with pigments where an
> object pattern controls the colors.
>
> --
> Tor Olav
> http://subcube.com
> https://github.com/t-o-k

Cool! I imagine turning this in to an animation. Peeling it like an orange.

Have Fun!


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