POV-Ray : Newsgroups : povray.binaries.images : Smoothing bicubic_patchs. A pain. : Re: Smoothing bicubic_patchs. A pain. Server Time
28 Apr 2024 05:46:38 EDT (-0400)
  Re: Smoothing bicubic_patchs. A pain.  
From: Tor Olav Kristensen
Date: 22 Aug 2018 17:15:00
Message: <web.5b7dd1369b869b6138c8b7240@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> "Bald Eagle" <cre### [at] netscapenet> wrote:
> >...
>...
> If you calculate the two partial derivatives (d/dU and d/dV) for each of the
> bivariate functions for a Bezier patch you can use these to reorient objects to
> align with the U-, V- and normal directions of the surface.
>
> This article contains some useful information about that:
>
>
https://www.scratchapixel.com/lessons/advanced-rendering/bezier-curve-rendering-utah-teapot/bezier-patch-normal
>
> The attached image shows cubes that are reoriented to align with the directions
> I mentioned above. It also shows a lot of splines that creates a grid on the
> surface of the patch.


Here's another image where the cubes have been scaled in the U/V-directions by
the lengths of the vectors used for reorienting them. (These vectors were
created with the partial derivatives of the bivariate functions for the Bezier
patch.)

--
Tor Olav
http://subcube.com


Post a reply to this message


Attachments:
Download 'scaled_cubes_on_the_surface_of_a_bicubic_bezier_patch.jpg' (426 KB)

Preview of image 'scaled_cubes_on_the_surface_of_a_bicubic_bezier_patch.jpg'
scaled_cubes_on_the_surface_of_a_bicubic_bezier_patch.jpg


 

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.