"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
> > I have been wondering if some dedicated POV-Ray projects could somehow
> > be 3D printed...
>
> I played with this some years ago:
>
>
http://news.povray.org/povray.general/message/%3Cweb.5682a213e23216e08da727310%40news.povray.org%3E
>
> This post was even replied to by Kenneth himself. Lurkers of the world unite!
>

Hi all; sorry for my silence (yet again!) I have been working on a scheme to
turn a POV-ray object into a 3D-printable .stl file-- ANY kind of object or CSG,
not just a mesh or mesh2.

From what  I've read in the  previously cited newsgroup posts here, they all use
POV-ray's trace(...) function to create a dense 'point cloud' of an object,
which is then ported over to Meshlab or Meshmixer to re-build the object as a
triangle mesh and to create an .stl file for 3D printing. That apparently works
well for some objects, but I can see that just about any tracing scheme will
have some limitations and difficulties-- with overhangs and undercuts, for
example, and hollow spaces/holes.

So I decided to go about it in a different way: 'pre-slicing'  the object within
POV-ray as a series of thin slices (.png rendered images, white against a black
background), then importing them into an app called '3D slicer.' It's a huge
(230 MB zipped!) professional-level viewer/manipulator for hospital CT/MRI
scans. Take a look here...

https://www.slicer.org/

It is free to download, which is quite amazing, and can import a stack of .png
or .jpeg images (the slices) to recreate the object. It can also output an .stl
file, for later importing into your favorite 3D-printer 'slicer' software such
as Cura, Prusa-slicer, Creality Print etc. (They turn the .stl file into the
final .gcode instructions for the printer.)

This app is very intimidating and mysterious at first glance, and the GUI and
its menus are somewhat non-standard.  I spent a week researching various
medical-tech videos on Youtube to figure out HOW to use and navigate even the
basic necessary menus, as the layout is not newbie-friendly (and is designed for
a totally different audience). The processing steps we are interested in are
complicated to explain in words, but luckily use only a very small subset of the
app's vast list of features. Once the few required steps are learned, it's easy!

So the whole process is like this:  pre-slice the POV-ray 3D object -->  rebuild
the object as 3D from the slices -->  output the .stl file -->  re-'slice' the
model as .gcode for 3D printing.  It's a roundabout way of accomplishing the
goal, I admit, but it works! I have already printed several test models in PLA
plastic.

I will try to put together a how-to explanation of the process as it relates to
POV-ray.

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