Rune wrote:


> My ultimate goal was quite similar to yours: To be able to define a list
> of points and a list of patches with corners in those points. Only
> difference was that exactly four patches had to meet in a point, but
> then the patches could have 3, 4, 5 or 6 edges. I abandoned it though -
> the triangular bicubic patch was coded by Micha Riser and improved by
> me. However, Micha Riser never coded similar patches for 5 and 6 edges,
> and I didn't understand the scientific papers on which the special
> bicubic patches were based, so I couldn't do it myself.

If you stich three 4-sided patched together you have a new patch with
6 edges all of which are cubic. (Actually you could do that with 2
but you lose some symmetry then).
If you need 5, you migth consider aligning 2 of these edges from 
neighbouring patches in such a way that they both are described
by the same cubic function. Then you can use that to connect a
single edge of another patch.
I did not have time to test that idea myself, but I suspect that
although the edges are seemless in mathematical space, there could
be cracks in POVRAY becouse of different approximations in the
neighbouring edges.

> Rune
> --
> 3D images and anims, include files, tutorials and more:
> rune|vision:  http://runevision.com **updated Dec 30**
> POV-Ray Ring: http://webring.povray.co.uk
> 
>

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