Ken <tyl### [at] pacbellnet> wrote:
:   Forgetting your thoughts on the hollow key word instead
: lets look at the different objects here and their properties.
: ...

  I have noticed that there is a lot of confusion about hollow/solid
objects, the 'hollow' keyword and whether a 'plane' object is a 2-dimensional
surface or not.
  For example, I remember a sample scene in the official distribution
of povray (at least pov3.0; I haven't checked 3.1) with a wall made this
way:
plane
{ z,100 hollow
}
  There wasn't any reason why that wall plane should be hollow. Obviously
the maker of that sample scene put that keyword to get rid of the
"camera inside non-hollow object" warning.
  (of course the right way to make that wall should be:
plane
{ -z,-100
} )

  I have frequently seen people confused with the plane object. They
obviously think about it as a 2D sheet, with no inside part, with both
sides as outside.
  Another big confusion is the concept 'solid and hollow object' and the
keyword 'hollow'. They don't know that solidness and hollowness have
nothing to do with CSG but only with media. There is also confusion about
the fact that povray actually only models surfaces, not true solid 3D
objects.
  I'm not saying I understand everyting, of course :)
  I'm still a little confused with the 'clipped_by' statement. I don't
know, if you clip off a part of an object, where is the inside and
where the outside of the object, specially at the hole. This will affect
only the media inside the object, of course. I have never tested it. Anyone
know something about this?

-- 
main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";while(i=
*_++)for(;i>1;printf("%s",i-70?i&1?"[]":" ":(i=0,"\n")),i/=2);} /*- Warp. -*/

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