POV-Ray : Newsgroups : povray.unofficial.patches : A bigger bicubic_patch? Server Time
2 Nov 2024 05:18:00 EDT (-0400)
  A bigger bicubic_patch? (Message 1 to 3 of 3)  
From: David Curtis
Subject: A bigger bicubic_patch?
Date: 11 Mar 2000 09:24:46
Message: <38ca572e$1@news.povray.org>
I'm wondering if/how I can create a bezier surface with more control points
than the limit of 4x4. I need at least 10x10. Can I use an isosurface to do
this? At first I tried to patch an array of  patches together, but of course
the seams are too sharp. I've only seen the equation for bezier curves
before, so I imagine that the equation for a bezier surface has to be more
complicated, maybe too much for an isosurface?

What I'm wanting to do is create a surface with x and z fixed on a plane and
have y variable. The surface is for a graph I'm making. I've thought of
making the surface from triangles. Is it possible to calculate (in POV) the
normals for the points of a triangle?

Anyway that's probably enough questions for now...

--
Dave.
mic### [at] sympaticoca


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From: ingo
Subject: Re: A bigger bicubic_patch?
Date: 11 Mar 2000 09:51:22
Message: <8EF4A5D00seed7@204.213.191.228>
David Curtis wrote:

>I'm wondering if/how I can create a bezier surface with more control
>points than the limit of 4x4. I need at least 10x10. ...

Ron Parker explained this a few times,
have a look at:

Newsgroups:  povray.advanced-users
Subject: Re: Q: smooth union of bezier patches
References:  <3720ce83.0@news.povray.org>
Message-ID: <3720d6ef.0@news.povray.org>

Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/


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From: Nieminen Juha
Subject: Re: A bigger bicubic_patch?
Date: 12 Mar 2000 09:15:10
Message: <38cba66e@news.povray.org>
David Curtis <spa### [at] junkmailcom> wrote:
: I'm wondering if/how I can create a bezier surface with more control points
: than the limit of 4x4. I need at least 10x10. Can I use an isosurface to do
: this? At first I tried to patch an array of  patches together, but of course
: the seams are too sharp.

  You have to connect several patches to get a bigger one.
  They are not usually intended to be created by hand. You have to be a
quite hardcore povrayer in order to be able to create them by hand.
  Creating them with a mathematical function (inside povray itself) is easier,
but not trivial either.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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