Alexander Enzmann <xan### [at] mitreorg> wrote:
: 1) When transmit is used, the shading model is now using the refracted
: ray to determine the color.  That wasn't how (or why) I added transmit -
: it's supposed to be an unrefracted ray (unaffected by IOR).

  Why? If you said to povray that the object has IOR, then it bends the
light rays (well, in this case the eye rays). I think that it would not be
physically correct that one type of light refracts and another type of light
doesn't (well, actually I'm not sure if the transmit is physically correct
at all...).

: 3) The shadow rays through a (partially) transparent surface aren't
: modified the same way as eye rays.  You end up with colored shadows that
: are either brighter or darker than the surface itself.  Results are even
: worse with distance based attenuation (extinction) in an interior.

  This usually happens because the ray passes through more than one surface
when going through an object.
  Povray doesn't model physically correct caustics anyways, so it doesn't
matter after all.
  Photon mapping is another story.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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