"Kenneth" <kdw### [at] gmailcom> wrote:

> I just discovered-- after all of my years of POV-ray'ing-- that this
> intersection box for rendering object slices can actually be ZERO thickness. It
> will still show the object slice at that 'infinitely-thin' plane. I already knew
> that a box could be made like that-- but didn't expect such an intersection to
> work.

I've probably discovered such a thing simply because I've accidentally made so
many infinitely thin shapes before.  :D

> I have two different slicing schemes at present, to see which one
> produces the better-recreated model in the '3D slicer' app: the zero-thickness
> scheme above, or a thickness that depends on the number of animation
> frames i.e. total slices rendered (which is what I have been using so far,
> mostly.) Either scheme renders just 2-D white-on-black images of course, but
> there *may* be a subtle difference in the result. More tests to do!

I would say that your render settings such as image size ("resolution") and
antialiasing values will have more of an effect than anything.
Also, depending on what your texture and lighting values are.
For what you're doing, I'd go for an orthographic camera, NO light, and an
emission 1 white.

Another idea, just to play with variations on the theme is to do something
shader-like, and either use the object pattern or inside to make a function that
you apply to a plane perpendicular to the camera.
Then you can simply move the plane "through" the space that your (virtual)
object occupies and take infinitely thin "slices" pixel by pixel as the plane is
rendered.
Better yet would be to just texture a box, or two triangles delimited by the
bounding box of your object (or a slice of it), to keep function evaluations to
a minimum and speed render time.

- BW



inside(O,V)
It returns either 0.0, when the vector V is outside the object, specified by the
object-identifier O, or 1.0 if it is inside.


Something extra wicked-cool would be to find a way to use a software to "unwrap"
the skin of your object as a uv-map surface and just print a thin layer as
triangles that could then be folded up into a "skin" that is the outer surface
of your object.

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