Shurakai wrote:
> Tor Olav Kristensen <tor### [at] TOBEREMOVEDgmailcom> wrote:
> 
>>I recommend that you read a little about Rational B-Splines.
>>
>>--
>>Tor Olav
>>http://subcube.net
>>http://subcube.com
> 
> 
> Well, actually i'm not a mathematical genius, sorry, i don't deal with
> mathematics at all ;). I'm chemist and mathematics was always a riddle for
> me. But there should be a way to define a nearly perfect circle using a
> cubic B-spline and putting the start and end controllpoint somewhere far
> away. but it did not worked. I tried a lot to shift the control points, but
> no way :((
> Here the spline and the pic.
> #declare C_Path4 = spline { natural_spline
>     -0.25      <  -26.666, 0,  0>,
>      0.00,     <        0, 0, 20>,
>      0.25,     <       20, 0,  0>,
>      0.50,     <        0, 0,-20>,
>      0.75,     <      -20, 0,  0>,
>      1.00,     <        0, 0, 20>,
>      1.25,     <   26.666, 0,  0>};
> 
> 
> 
> Maybe i'm totally wrong and a circle can't be declare by a spline

You can not make a perfect circle with any of POV-Ray's
inbuilt spline types (AFAIK).

I'm in a hurry now, so I don't have time to explain further.
Maybe later...

Btw.: The Natural Spline is not a B-Spline.

-- 
Tor Olav
http://subcube.net
http://subcube.com

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