Rune wrote:
> andrel wrote:
> 
>>If you stich three 4-sided patched
>>together you have a new patch with
>>6 edges all of which are cubic.
> 
> 
> The way you propose to make a 6-sided bicubic patch requires stitching
> together 3 bicubic patches so their corners meet in a point. As you can
> read in other posts in this thread, you can't do that and still have a
> smooth surface.

I know, I was one of the people to make that claim.

> There is no way to create smooth n-sided bicubic patches from 4-sided
> bicubic patches.
I take that as a challenge. The major problem with stitching together
of the patches is that the derivative for a point on the edge depend
on all 16 parameters of the patch. In your and Tor's scheme you have no
control over many of the other points because they have there own
constraints. But in this case you are completely free to choose any of
the constants, so perhaps in this case it is possible. Most of my week
is scheduled for triangles and general meshing around, so it has to wait
untill the weekend before I can do something on patches again :)
In the mean time I will post some patch-work ball I created earlier.

> 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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