Wasn't it Simon Lemieux who wrote:
>> BTW, anybody knows how I could scale the radius of the twisted cylinder?
>
>Oh and I forgot, here is the function:
>function { 
>  x*cos((z+2*clock)*2*pi) + x^2 + 
>  y*sin((z+2*clock)*2*pi) + y^2
>}

Depending on what you mean by "scale", you might want to do something
like this to cause the radius to vary linearly as z changes

#declare  F = function { 
  x*cos((z+2*clock)*2*pi)*(z-A)/B + x*x + 
  y*sin((z+2*clock)*2*pi)*(z-A)/B + y*y
}

[I've also changed the syntax from being MegaPov specific to something
that will also work in POVRay, so that I could test it].

Where "A" specifies the point along the z axis where the radius would
become zero, and B controls the rate at which the radius reduces.


If you just want to scale the while thing, then you'll find the "scale"
keyword useful. It still works with isosurfaces.

-- 
Mike Williams
Gentleman of Leisure

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