Skip Talbot <Ski### [at] aolcom> wrote:
> Kenneth, doesn't it seem logical, and wouldn't you assume that the 
> vectore returned by trace would indeed be a unit length vector?  What 
> else would it possibly be?

  Why is it so obvious that the normal vector returned by trace() is
normalized?
  Normal vectors are usually results of some calculation which often do
not by itself return a normalized vector. For example, if you calculate
the normal vector of a triangle using cross-product, the result will not
be normalized and you have to it separately.
  POV-Ray primitives probably return their normal vectors already
normalized for convenience, but it's not something obvious. They could
perfectly well return non-normalized normal vectors.

  (For those who don't know the term, normalizing means calculating a
vector with the same direction as the given vector but with length 1.)

-- 
                                                          - Warp

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