3DM file (Rhino)
The native file format of Rhinoceros 3D (Rhino), storing NURBS geometry, meshes, layers and materials.
What a 3DM file stores
3DM files can hold NURBS surfaces and polysurfaces, meshes, curves, layers with names and colours, materials, render meshes and more. The format is published through openNURBS, so many tools can read it.
Why 3DM is great for rendering
The biggest advantage is layers. Jewelers usually keep metal, centre stone, halo and pavé on separate layers, and that structure survives the upload. In RenderMyJewels, layers named with words such as Diamond, Gem, Stone, Ruby, Pavé or Halo are treated as stones automatically, and the other layers normally start as metal. Any layer can be switched between metal and gem in the Layers tab, and each one can take its own preset, so a centre stone, a halo and a band can all carry different materials.
Saving 3DM files for upload
- Save normally, not with Save Small. Save Small removes the render meshes stored with NURBS objects, and some viewers then cannot display the surfaces.
- Name your layers clearly. One layer per material makes renders faster to set up.
- Hide or delete construction geometry. Curves, cutters and helper objects add size and can show up as stray lines.
- Stay within the size limit. 3DM uploads can be up to 200 MB.
When to export something else
If a 3DM file is very large or uses features a viewer cannot read, exporting a GLB from Rhino is a good fallback, since GLB keeps object names and materials in a compact mesh file. See the CAD software guides for export settings by program.