Hi Gaston, no there isn't any way to do that with MoI alone - MoI is not designed to be a polygon editing program so that also means that it does not try to open polygon model type files.

The data in STL files is just a totally different kind of data (triangular facets) than what MoI is set up to work on (NURBS surfaces).

MoI can export to a polygon file by dicing up smooth NURBS surfaces into little triangular facets, but it is not easy to do the reverse and "undice" a whole bunch of triangles back into large NURBS sheets.


> Beside resorting to Rhino, how could I do this?

Rhino would work because it is a kind of "dual mode" program that works on both polygons (kind of) and also NURBS.

But pretty much any polygon modeling tool would probably be able to merge different polygon chunks together and re-export as STL as it sounds like you want to do.

For example, Silo, Modo, Cinema4D, 3DS Max, etc...

There are also some STL-specific programs that would probably do the job too, there is one program called Magics which is often used for STL related functions. There is a "lite" version of it called MiniMagics that should probably be able to import different STL files and output a combined file:
http://www.materialise.com/materialise/view/en/2562719-MiniMagics.html

One thing to note though is that if you try to combine pieces together like you are talking about with no editing, you will end up with an STL file that has multiple solids in it rather than only a single solid which is more what it was originally designed to hold. That may cause problems with certain applications, but some stuff may be ok with it.

- Michael