clipka <ano### [at] anonymousorg> wrote:
> Am 14.06.2010 19:14, schrieb AlexLens:
>
> > In the meantime, here is the lathe code, it's a bit long so I didn't initially
> > post it:
>
> Here's your problem:
>
> > //--------------------------------PLANO-CONVEX LENS LATHE-----------------------
> > lathe
> > {
> >    quadratic_spline
> >     1000,
> >    <1.000,0.0000000000>,
> > <0.999,0.0005769655>,
> > <0.998,0.0011531620>,
> ...
> > <0.002,0.2679481924>,
> > <0.001,0.2679489424>
> >
> ...
> > }
>
> Quote from the docs, section 3.4.1.7, "Lathe" (emphasis added):
>
> "The curve is *not* automatically closed, i.e. the first and last points
> are not automatically connected. You will have to do this yourself if
> you want a closed curve. The curve thus defined is rotated about the
> y-axis to form the lathe object, centered at the origin."
>
> As you do not explicitly close the curve, all you get is a surface (the
> curved side), not a solid body - which pretty much messes up reflection
> computations. (When the rays encounter the curved surface, POV-Ray
> thinks they would be /entering/ the object there rather than leaving it,
> having pretty much the same effect as using a planar-convex lens with an
> ior of 0.666 rather than 1.5.)
--------------------------------------------------------------------------------
clipka, thanks a lot!

Right now I am trying to intersect it with a plane to bound the flat side of the
lens.  Is that how you would close this?

Also, are some of my settings unnecessary, it seems to be taking longer than I
would expect it to..maybe this method overall is not the best way to implement
this lens from data points?

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