J-Print News wrote:

> Thanks Francois, that's exactly what I wanted to know. Except for the NURBs.
> If anyone knows the Equations for NURBS, I'd be very grateful.

NURBS = Non Uniform Rational B-Splines, aka Bezier Patches, Bicubic Patches,
etc.  It's all the same stuff.
...Chambers

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> NURBS = Non Uniform Rational B-Splines, aka Bezier Patches, Bicubic
Patches,
> etc.  It's all the same stuff.
> ...Chambers
>

Thanks. I suspected it was something like a 3d bezier. Seems like I wasn't
far off.

Nekar

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In article <3A692D00.35295741@hotmail.com>, Ben Chambers 
<bdc### [at] hotmailcom> wrote:

> NURBS = Non Uniform Rational B-Splines, aka Bezier Patches, Bicubic 
> Patches, etc.  It's all the same stuff.

Depends on what you mean by "same stuff"...they are *not* identical as 
far as I know, but they are all spline based objects. "Bezier patch" and 
"bicubic patch" seem to be used interchangeably, though. And MegaPOV 
supports a "rational bezier patch" object.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Another question. What exactly is meant by the term 'patch'?

Thanks

Nekar
Chris Huff <chr### [at] maccom> wrote in message
news:chrishuff-D120DF.11515920012001@news.povray.org...
> In article <3A692D00.35295741@hotmail.com>, Ben Chambers
> <bdc### [at] hotmailcom> wrote:
>
> > NURBS = Non Uniform Rational B-Splines, aka Bezier Patches, Bicubic
> > Patches, etc.  It's all the same stuff.
>
> Depends on what you mean by "same stuff"...they are *not* identical as
> far as I know, but they are all spline based objects. "Bezier patch" and
> "bicubic patch" seem to be used interchangeably, though. And MegaPOV
> supports a "rational bezier patch" object.
>
> --
> Christopher James Huff
> Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
> TAG: chr### [at] tagpovrayorg, http://tag.povray.org/
>
> <><

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J-Print News wrote:
> 
> I'd like to find out more in depth info about the equations for Iso
> surfaces, NURBS and beziers.
> For instance, how copuld I use  them in BASIC?

Slowly?

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"J-Print News" <vir### [at] iconcoza> wrote in message
news:3a6bd499@news.povray.org...
> Another question. What exactly is meant by the term 'patch'?

Patches are like 2D areas which can be curved in a 3D way.  Like parts of a
patchwork quilt.
Triangles and polygons could be said to be patches also I suppose, except you
can't bend a triangle physically and the usual polygon is flat too (although
points could leave the 2D plane).
Hopefully I'm not misinforming too much.

Bob H.

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J-Print News wrote in message <3a6bd499@news.povray.org>...
>Another question. What exactly is meant by the term 'patch'?


A patch object is a finite object without a well-defined interior.

--
Mark

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