Who needs this
Jewellers sending a ring to a printing or casting service, makers who got a
Rhino file from a designer, students without a licence at home: the .3dm
is the source, but the printer workflow needs STL or 3MF.
How it works
The converter loads rhino3dm, McNeel's WebAssembly build of openNURBS (about 2.7 MB, once), and collects everything that can be meshed:
| In the 3DM | In the STL |
|---|---|
| Mesh objects | Converted as they are |
| Polysurfaces, extrusions | From Rhino's cached render meshes |
| SubD | Meshed from the subdivided control net |
| Blocks | Expanded at every placement |
| Curves, points, dimensions, text | Not converted |
The result is merged into one mesh in millimetres.
Getting the best mesh from Rhino
The quality of polysurface conversion is the quality of Rhino's render mesh. For printing, the default render mesh can be coarse on small curved details. If you have Rhino, set a finer custom render mesh (Document Properties → Mesh) before saving — or use Rhino's own export to STL with a fine tolerance. If you do not, this converter gives you the best mesh the file contains.
Before printing or casting
Check the summary's watertightness line. Jewellery models built from separate surfaces, or with intersecting parts, may need a Boolean union in Rhino before they print as one solid.
On a phone
3DM conversion works in a phone browser. The Mes3D app for iPhone, iPad, Mac and Android opens 3DM files, measures them and exports STL, OBJ or 3MF.