Howdy,

I have been using povray for several years but never really learned it so I
probably qualify as a "new user".

I am drawing solutions to 3D packing puzzles, like this one:
    http://www.bumblebeagle.org/polycubes/rt/pentacubes_5x5x5/index.html
(if you click "next" it adds the next piece to the drawing).  Most of what I
have done has been by piecing together examples that I found online.

I am now trying to make my puzzle pieces look more interesting and I found an
example using agate as a surface normal.  I put together an experiment using
this, of which you can see a two-piece drawing here:
    http://www.bumblebeagle.org/blarf/povray/N1_1_2.html
My problem is that two pairs of cube surfaces are identical (other than color).
These are faces that face the viewer's right shoulder-- the two rightmost ones
on the top row and the two leftmost ones on the bottom row.  These two pairs
seem to have the same "texture" pattern ("texture" in quotes because I don't
meant the povray texture keyword).  Hopefully other people see this the way I am
seeing it.

Following the example that I found long ago at
    http://en.wikipedia.org/wiki/File:AGK-pentacube.png,
and modifying it based on some other examples I found, my pieces are declared
like this:

  union
     {
     ... a single cube object
     ... another single cube object
     ... etc.

     texture
         {
         pigment { rgb c }
         finish  { specular 0.6 }
         normal  { agate 0.35 scale 1.3 }
         }
     }

First, I have not been able to find a description of what modifiers I can use
for normal that would apply to agate.  I have been to these two pages
    www.povray.org/documentation/view/3.6.1/363/#l157
    www.povray.org/documentation/view/3.6.1/339/
but I am not finding what I need.

Second, I understand the concept of the agate pattern being a function in 3-D
space.  And that it samples that function along the surface of my pieces and
uses that as the normal (which I assume has to do with the angle of reflection).
 It appears that that function repeats for the two planar segments that I
mention above.  I thought that changing the scale value might correct for that--
my hope was that "scale" would expand or contract the agate function in 3-space
and since my cubes have unit size then using a non-integer size would correct
the problem (am I making sense?).  Anyway, it doesn't.  And I haven't been able
to find a description of what exactly "scale" does.  Or a list of other
modifiers that would apply for agate.

Anyway, thanks for any help,
Frank B

P.S. my full source for this can be found at
    http://www.bumblebeagle.org/blarf/povray/N1_1_.ini
    http://www.bumblebeagle.org/blarf/povray/N1_1_.pov
and my command line is
    povray N1_1_.ini width=320 height=240

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