>  Making a lens out of a lathe works very poorly. The reason is that
> none of the available spline types will give you a G2-continuous [*]
> connection on the control points. However G2-continuity is essential
> to optical surface design.
>
>  Since most lenses are modeled with polynomials anyway, I would
> advise you to use an isosurface with the corresponding polynomial.
>
>   Jerome
>
> [*]
> http://en.wikipedia.org/wiki/Geometric_continuity#Geometric_continuity
> --
> mailto:jeb### [at] freefr
> http://jeberger.free.fr
> Jabber: jeb### [at] jabberfr
-------------------------------------------------------------------------------

Thanks for the reply!

I had no clue the cubic splines were not G2 continuous as they usually are.  The
documentation page for the cubic spline makes it seem like it is necessarily G1
continuous, however.  I'm guessing that POV-Ray only needs to know the first
derivative to know how a photon would interact with a surface, so this method
still should work.

As for the Isosurface, I don't have an analytic function to input to POV-Ray, so
maybe that wouldn't work?

What do you all recommend as the fastest method to make this lens just given the
numerical data I have?

Post a reply to this message