Heya -- two questions have reared their ugly heads as I mess around with
MegaPOV.  Firstly, there seems to be some portability problems with
respect to isosurfaces -- namely division by zero.  Rendering the
following scene produces two completely different results under Linux
and Windows.  Under the former, the result is pure black.  The latter
spits out a while circle...

#version unofficial MegaPov 0.5;
isosurface{
  function{1/0}
  contained_by {sphere{0,1}}
  threshold .5 pigment {rgb 1}
}
global_settings{ ambient_light 10}
camera {location <2,0,0> look_at <0,0,0>}

I would hesitantly put forth that the all-black version is the "more
correct" version, as the isosurface evaluates to +infinity at every
point -- and +infinity is never equal to 0.5 (the threshold) so there
should be no "surface" at all.

The other, unrelated, quirk is that of nested macro definitions.  Why
does MegaPOV specifically complain about them, and refuse to parse
them?  Is there a workaround?  Because otherwise Chris Colefax's
wonderful spline macro file is useless in MegaPOV..
Thank ye for any enlightenment,
-Alex V.

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