With respect, Vitaliy, I ran your code on my I5 laptop, just up to exp = Show . . .

It took 20 minutes, and this just to tessellate a simple solid which was only a composition of rectangular solids -- a trivial job. None of my real applications are so limited. For any meaningful STL export, Mathematica needs a fully functional tessellation capability for solids with curved surfaces. A first step is to be able to handle all the solids which can be generated by Mathematica 3D primitives. But what is really needed is to extend that to all solids defined by closed parametrically defined surfaces.

This does not cover export of solids to modern CAD standard formats such as STEP, IGES, and Parasolid. For this there may well be a restriction requiring the solid to be a composition of accepted primitives. But this needs to be undertaken before WRI claims to be capable of interchange with current standards,

Kind regards,

David

@David I'm 100% with you. And I confirm the need for Parasolid import and export. Some CAE softwares are based on it, and many have it as an import/export format.

This type of functionalities are typically perfect for intern projects, which should easy the constant updatings that are needed to follow the formats revisions.

Very soon, with the handheld 3D scanners that will come with future revisions of phones and tablets, everybody will be manipulating 3D models, printing things at home after having scanned them, with their phones, in the middle of the street, or integrating into their daily work activity some of the engineering stuff that is currently only available at a high cost, to people that pay the thousands of dollars that cost a scanner, and that carry it around with huge operation manuals... This is going to change the way we register the world, in the same way the everybody has a camera in the pocket has changed the way we take pictures. Just imagine arriving at home and printing your kid, riding a pony, playing the piano, etc.

So, tomorrow, we will need cloud of points processing capability, automatic fitting of primitives into the scanned cloud, importing and exporting capabilities that keep track of the texture information (since that even the first versions of phones and tablets will come with "color" scanning), etc. This means that we need extremely good 3D models import and export, and I can confirm that this is currently not the case (even DXF had text problems not so long ago, and probably still has). We will need surface wrapping algorithms (balloon meshing), to correct gaps on imperfect meshings, or directly on clouds, etc.

To add to this, the impressive geometry functions addition we had on the latest version of Mathematica, to cover the FEM necessities, etc, has approached Mathematica a little closer to the needs of the engineer. And so, we are in need of dynamic rotating pivot point manipulation (to be able to zoom a 3D graphics, and still rotate without getting dizzy), dynamic change of rendering options without resetting the plot definitions (wireframe, hidden lines, shadow casting, etc). etc etc.

@Tom I'm sorry for taking profit from a moment of enthusiasm, going a little outside your initial post, but I think that these topics are inline with the necessity of taking 3D engineering serious (since 3D for enthusiasts is closer than ever). Not having a perfect interaction with ray-tracing capable renderers, or omitting major CAD formats is so 90's...

So, +1 for perfect STL support, and everything that brings engineering topics to the world of Mathematica

(also, these kind of improvements fit well on the new trend of having a more continuous product evolution, which is the same to say: WR, can you please push this kind of updates as soon as they are available, instead of in major releases?)

PS - by the way, does anyone knows if there are projects working on multiple POV cloude of points scanning/filming synchronization? That is, if in the future I have 2 or 3 iPhones 9, scanning a scene at the same time, from multiple angles, will I be able to spin the live action scene looking at a 4th device? The future looks promissing!