Hello!  While I'm not exactly a new user of POVray, this has been bugging me on
and off almost since I started raytracing.  I just *cannot* wrap my head round
the trace function!  My usual approach of taking the example and changing it to
see what happens is not working here, for some reason.  It's very irritating
because I feel I'm missing something small and crucial, but I find the tut in
the POVray help file rather scanty and most of the examples I've found online
are a lot more complex than I want, which makes breaking them down into
comprehensible bits for easy digestion a challenge.  It probably doesn't help
that I've had no formal progamming training.

If someone could break down (preferably in words of one syllable!) the component
parts of the trace function; such as the purpose, suggested parameters, what's
essential and what's not, etc., I would be embarassingly grateful!

At the moment, what I would like to do is place some objects on the following
isosurface.  Some of them will be individual, others I would like in rows or
groups and they should ideally conform to the shape of the surface.

#declare fn_Pigm_01 = function {
 pigment {
  bozo
  turbulence 0.5
  colour_map {
   [0 colour rgb 0]
   [1 colour rgb 1]
  }
  scale 0.5
  rotate y*-64
  translate <0.3,0,0>
 }
}

#declare Map = union {
 isosurface {
  function { y-fn_Pigm_01(x/1.5,y/3,z/2).gray*0.7 }
  pigment { Yellow }
 }
}

[I have the y-axis vertical and the x-axis parallel to the plane of the screen,
if it matters.]

Thank you once again for reading this and for any help or comments, and sorry
for being so dense!

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