Thanks BE and Thomas!

You would not *believe* the number of hours I have spent on this project, with
the explanations and code and screenshots-- re-editing almost daily, adding
stuff, erasing stuff, making corrected screenshots, choosing what to include and
what to leave out as unnecessary, making more 3-D test printings etc etc. I kept
telling a few friends that I could probably write a BOOK about it all. But it
sure has been fun :-) For the last couple of weeks, I've been almost
single-minded about finishing it. Now I'm exhausted, ha.

Over the intervening months since last November, I also made some important
discoveries about how 3D SLICER actually works-- by trial and error. My earlier
tests and printed model examples used a much simpler slicing scheme-- which
resulted in squashed-or-stretched results in that app, that I had to re-scale by
eye. Then a 'eureka' moment FINALLY occurred, and my 'automatic' slicing scheme
was the result.

BE: I thought a lot about your earlier suggestion of using POV-ray's 'object
pattern' as a simpler and standard approach to the slicing-- but 3D SLICER's
method of operation makes that approach difficult.  (The proper scaling of the
object there requires a certain number of image slices, not arbitrary like I
originally thought.) A POV-ray object's bounding-box size turned out to be the
answer to that problem-- and object_patterns don't have those. Of course, an
object_pattern has a 1:1 size correspondence with the object it is *made* from,
so I could have used that to get the bounding-box size. Hmm, at some point I
might re-write my code to try that approach!

In some ways, I feel that this entire object-slicing-to-3D-SLICER idea is just
an interim step to the POV-ray 3-D printing problem... waiting for some clever
fellow to take the image-slices and instead create a triangle mesh (and .stl
file) *directly* from the image pixels. Like POV-ray does with height_fields
from a single image, but 'stitching together' all the triangles from all the
slices. Then we would have a direct-to-.stl solution!

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