Seems it's not a direct 3dm file but a conversion of a Quickdraw3D file by Polytrans transformer :)
Maybe this explain that :)

Thanks, so that means we have to get 3dm from Rhino directly and not converted by another app...

I don't know maybe some nature of files can be convert in 3dm format with success !
Seems Michael answered that there also 3dm format readable or not depending of the version and nature!

Hi JTB - yeah these are not Rhino 3DM files, they are actually in a different format.

Back some time ago Apple introduced a format for QuickDraw3D, and they called it 3D Meta-File. These would normally have a .3dmf extension, but on Windows machines sometimes the extension was shortened to .3dm .

This kind of file is not really very common though, most of the time a .3dm file will be a Rhino one.

I think that the PolyTrans converter can export both Rhino .3dm as well as an Apple 3D Meta File, so probably your friend accidentally picked "3DMF" off the save as list, instead of "Rhino .3dm".


However, there is another problem that you'll probably run into here - your friend seems to be exporting polygon mesh data, not NURBS data.

It is possible to store polygon data in a Rhino .3dm file, but MoI will not read that type of data in, MoI only reads in NURBS curves and surfaces.

If you want to bring polygon data into MAX, you should try one of the more common polygon formats, like OBJ or 3DS.

- Michael

Thanks for such a detailed answer, I guess it is because the polygonal data in 3dm and not the Apple format

Hi JTB - the ones you attached above are definitely in the Apple 3DMF format.

When trying to open them in Rhino, Rhino reports "AR0020A.3DM is not a Rhino file", and if you open them in notepad you'll see that they are text files where the first few lines read:

3DMetafile

#
# QuickDraw 3D file: D:\ARecon3d1\3Dmf\ar0020a.3dm
#

- Michael