Greg M. Johnson <"gregj56590:-)"@aol.com> wrote:
: I am working on an animation.  I had the characters running on a plane.
: The render time for 50 frames was maybe 12 hours. I wanted to make them
: running instead on one long narrow strip.   I set up some CSG with the
: plane, by looking at the intersection of three planes.   The render time
: increased to over 24 hours.   I don't have the parsing vs. true render
: time, etc., in front of me.  Does CSG with infinite objects greatly
: increase overall render time?

  Yes.
  Each infinite object is tested for each pixel. If you have 1000 infinite
objects (like planes), povray will make 1000 tests for each pixel although
the intersections of the planes was a little polyhedron in the middle of
the screen.
  This can be speeded up with bounding boxes. If you bound this little
polyhedron with a properly scaled box (which encloses the polyhedron completely
inside it), then the 1000 tests will be made only when the ray hits the
box and nowhere else.

: Would a 2000 unit long box take less render time than a CSG'ed plane?

  Absolutely. A box object is highly optimized and it will surely render
much faster than a box made by intersecting planes.
  Only the size of the box on screen affects the render time, not the size
of the box on povray units.

-- 
                                                           - Warp. -

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