Hi Pilou, I would not advise to try and convert that file as a sub-d mesh. It's 108 different mesh objects, with approx 70,000 polygons all triangles no quads at all.

It is not structured to be used as a sub-d control cage and so it is not one that I'd expect to work well with the sub-d converter.

If you did want to try it you would need to make sure you have a very large amount of system RAM.

- Michael

So seems normal that this crashes! :)

With ImportObj:
In MoI3, hung up at 12,000 of 70,154.

In MoI4 beta, 0 of 70,154, error: Invalid index: 0 length = 0...

This type of model where the data is made up of a large number of little triangle facets, is not suitable for import into MoI. MoI is just not the right tool for opening that type of model structure.

You can export something like that out of MoI but not import it into MoI.

- Michael

Hi Pilou,

> So seems normal that this crashes! :)

Well it would be good if it didn't crash even though it's not expected to give you an actual useful result.

Probably the crash can be fixed for MoI v5. If it was a sub-d mesh which wasn't working right then that would be a higher priority to fix.

- Michael

Or maybe i had not enough hard memory...( 8 Gigas)

Hi Pilou, well even if it's not enough memory it's better to just bail out instead of crashing. It can be kind of difficult to catch every place where it can happen though.

- Michael

Hi Michael,

Thank you for your reply! Are there any conversion tools you might recommend that can convert the faceted polygon mesh into a format that is suitable for MoI (NURBS)? I'm honestly not sure if I'm asking the question properly. I played around with Meshmixer, but not sure if it can do the trick.

My 3D Printer splicer (FlashPrint) was able to import the .obj. However, when it imports it does report errors and attempts to repair it. Yet, it still was able to print the models which turned out decently (image attached).

I'd love to be able to exchange models between GS and MoI3d and if some conversion tool in-between is necessary, it wouldn't be a problem for me at all.

Thank you again!

Jon

Hi Jon,

> Are there any conversion tools you might recommend that can convert the faceted polygon mesh
> into a format that is suitable for MoI (NURBS)? I'm honestly not sure if I'm asking the question properly.

Well there are such tools but they are quite specialized - it's not like a matter of changing how things are just packaged up and formatted like many file format translations, you're instead talking here about a major change from one type of data (small facets) into a different fundamental type of data (spline CAD surfaces).

It's generally referred to as "Reverse engineering", if you do some searches on that you can find some software for it like Geomagic Wrap for example. You can also look for software for converting 3D scans into CAD models which is closely related.

But since it's a specialized field you'll probably find the software is quite expensive and will require a substantial investment in time to get good results, like in some software you manually guide the process by sketching a large patch structure on the faceted mesh.

That can be a feasible investment if it's an important part of your design process like you know you want to sculpt things in clay and then convert to a CAD model.

But for the most general case the polygon model data like you attached above is just not suitable for use as a CAD model.

- Michael

In general you must decimate your object and for Moi transform triangles in Quadrangles...
MeshLab is free and can makes that...http://www.meshlab.net

Thank you so much for your detailed reply, Michael! I did some more research and there is a "Pro" version of GS that appears to be able to export IGES (.igs) file format. I'm not sure if I'll run into the same issue, but I'm pursuing trying to get this option enabled in the beta to see if I can import models into MoI. If I have any success, I'll report back here. Thank you again for your support!

Best Regards,

Jon

Or more easy the free InstantMeshes https://github.com/wjakob/instant-meshes

So in Moi ;)

Hi Jon,

re:
> I did some more research and there is a "Pro" version of GS that appears to be able to export IGES (.igs) file format.

That's definitely worth a try. It's not automatically assured that it will help, it depends on what they put in the .igs file. Like for a sphere object do they write it as a sphere object in the IGES file or do they write out 1000 little flat facets for the sphere.

But if they remember that the object was a sphere and can write out that higher level representation then that could work.

- Michael

Thank you Frenchy, that tool looks pretty cool! I'll give it a try

That's awesome that you were able to get it imported! I've not yet figured out the file type that will import. I tried .dxf and nothing happened (I did follow the tutorial, exported as .dxf). I must be missing something. My beta 4 expired though, so can't try it there :(

Hi Jon, the current v4 beta doesn't expire until Oct 12, 2019 , you can get it at http://moi3d.com/beta.htm .

- Michael

re: DXF - MoI will read only drafting entities from DXF files like lines, circles, arcs, polylines, and spline curves. There are a lot of other possible thing that can be stored in DXF which MoI will not read. Probably in your case that data was stored as polygon meshes and like I described earlier MoI is not designed to work with polygon mesh data.

- Michael