Yes, that was me.  I sent my code to somebody, but I don't think they ever
took it farther than I did.  I intended at one point to read some info
on better ways to subdivide NURBS, but then I got working on photon mapping
and that's kept me busy for a while (and will continue to in the near
future, at least).

Regarding your proposed patch - if it is fast, that would be nice.  POV
currently subdivides bicubic patches.  It has an option to subdivide only
as needed (practically 'direct rendering') but this is much slower than
pre-computed subdivision.  If you have a technique that is fast, that
would be great.

The recursive definition for NURBS is a bit more complicated than the
definition for bezier surfaces, which makes subdivision computation a
bit more costly.  I've been told that there are efficient ways to do
the subdivision, but I have not investigated the matter closely.

The really slow NURBS code that I wrote (just to see if it could be done)
is simply a parser front-end to the triangle mesh object.  In other words,
if you make a NURBS surface with what I did, it is a mesh object
internally.  If you want the code, let me know where to email it to.

-Nathan

Mike wrote:
> 
> A long time ago someone mentioned that they had written a preliminary
> patch for NURBS.  I think it was Nathan but the messages I have don't
> seem to go back far enough.
> 
> Anyway, the person offered to share it with anyone interested.  If I can
> find the time, I plan on writing a patch to do direct rendering of
> bicubic patches, and it seems it should be possible to include NURBS.  I
> could use any help I could get, so it would be great if whoever has that
> code could forward it to me.  :)
> 
> I hear that the direct approach causes rendering artifacts, but I'd like
> to try it just the same.
> 
> -Mike

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