chr### [at] maccom (Chris Huff) wrote in <chrishuff-
6D1A7E.18382109072000@news.povray.org>:
>The trace() function is not difficult to understand. It just finds the 
>first intersection point of a line with an object, and optionally the 
>normal.
>An approximation would be quite easy to do, with the trace() function 
>and the ReOrient() macro. This wouldn't be perfect, and on many 
>combinations of surfaces would give slightly incorrect results(the 
>objects intersecting in the area of contact), but should be adequate for 
>most purposes.

  Thanks Chris.  I've re-read the MegaPOV docs regarding trace and I think 
I can get something going now.  I guess the only question I have now is how 
do I figure out the 'start' vector for arbitrary areas of the object being 
traced.  I guess I'll just have to go the trial-and-error route, geometry 
was far from my favorite class way back when I was in school.  <grin>  Hmm, 
can anyone supply a formula in POV code that will, assuming <0,0,0> as the 
base vector, take an angle, rotation around the y axis, and minimum radius, 
and return a new vector?  
  Warp: I understand your concern for matching surfaces, but I'm actually 
not worried about that bit.  I should have asked for a point on a surface, 
sorry.  I'm thinking of something like short pipe sections covering parts 
of a stretched sphere, that sort of thing, so it won't matter if parts of 
the small objects are embedded in the surface of the target object.  
  Anyway, if I get something figured out I'll post it.  Thanks everyone!

-- 
Rich Allen
(Remove SPAM from my address to reply by e-mail)

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