File formats
3D file formats for jewellery, and what each one keeps.
3DM, STL, OBJ, GLB, FBX, 3MF, USD and STEP compared: what the file holds, which ones open in Jart and how, and what to export from your CAD program for the best render.
The formats compared
Jart opens 9 of these 10 format families in the browser; nothing is uploaded. For a render, the file that keeps part names and separate parts wins: names let Jart assign metals and stones, and separate parts let the band and the head take different metals and finishes.
| Format | What the file keeps | Opens in Jart | How Jart opens it |
|---|---|---|---|
Rhino 3DM.3dm | NURBS surfaces and solids, the render meshes Rhino saved for them, object names, layers, materials, blocks and the model's unit system. | Yes | Opens the render meshes, not the NURBS surfaces: a file saved without them opens empty. Object names become part names for Auto assign; the unit system is read; curves, points and construction objects are left out; objects on hidden layers come in hidden. MatrixGold and RhinoGold files are 3DM too. |
GLB and glTF.glb .gltf | Triangle meshes with node names, physically based materials and textures, optionally compressed (Draco, Meshopt, KTX2), and animations. Units are metres by definition. | Yes | The format Jart is built around. Compressed meshes and textures decode in the browser; animations come in at their resting pose. A .gltf with separate .bin and texture files needs those files too. Jart also exports GLB. |
OBJ.obj | Meshes with object and group names; colours and textures live in a separate .mtl file. No units. | Yes | Opens with its .mtl when you select both (or ZIP them); without it the shapes come in grey. Taken as millimetres. Large files are read in the background. |
STL.stl | Triangles only: no part names, no colours or materials and no units. The standard file for 3D printing and casting. | Yes | Opens as one part named after the file, taken as millimetres; choose its metal or stone yourself. A binary STL can hold up to 1,666,666 triangles. Jart's caster pack (with the cast check) exports the metal as STL. |
FBX.fbx | Meshes with names, materials, textures and animation, common between animation and game tools. | Yes | Opens with its names and materials; taken as millimetres. |
3MF.3mf | Meshes with colours and materials in one zipped file, made for 3D printing. | Yes | Opens with its parts and colours; taken as millimetres. |
USD and USDZ.usd .usda .usdc .usdz | Whole scenes built from layers, with meshes, materials and animation. USDZ is the packaged form Apple uses for AR. | Yes | Opens simple scenes; complex composition, animation and special shaders may not come through. Jart exports USDZ for View in AR on iPhone and iPad. |
PLY.ply | Triangles, often with colours per vertex, typical of 3D scans. | Yes | Opens as one part with its vertex colours; taken as millimetres. |
Collada, AMF, 3DS, VTK and VRML.dae .amf .3ds .vtk .wrl | Older exchange formats for meshes, with or without materials. | Yes | Open as meshes; taken as millimetres. Export a GLB or 3DM where you can. |
STEP and IGES.step .stp .iges .igs | Exact CAD geometry (solids and surfaces) for engineering exchange, with no display meshes. | No | Not opened: a browser needs a mesh. Open the file in your CAD program and save a 3DM with render meshes, a GLB, an OBJ or an STL. |
Which format to export for a render
From Rhino, MatrixGold or RhinoGold, save the 3DM itself with render meshes, or export a GLB. Both keep each object as its own part with its name. Step by step: render a Rhino 3DM in the browser and render from MatrixGold or RhinoGold.
From other CAD programs, prefer GLB, then OBJ with its .mtl, FBX or 3MF. Use STL only when nothing else is available: it arrives as one part, so the stones cannot be told from the metal.
For casting, STL remains the file casters and printers ask for; keep sending them your CAD program's STL. Jart's renders do not need the casting file's resolution, so a lighter display mesh renders the same.
Units and true size
GLB and glTF are in metres by definition and a 3DM says its own unit system; every other format is taken as millimetres, the unit jewellery CAD uses. If a design opens at the wrong size, set the file's real unit under Scene → Advanced → Source units. Design Facts, View in AR and the GLB export all use it.
How big a file can be
One design can hold up to 10,000,000 triangles, 5,000,000 vertices and 20,000 meshes. The files you open together can add up to 512 MB, at most 512 of them, and a ZIP may unpack to 512 MB. A ZIP with several models asks which one to open. Textures can only come from your own files, never from a web address.
What Jart exports
- Images: PNG, JPEG, WebP, PNG 16-bit, EXR.
- Video: MP4 or WebM turntables, and 360° spin frames in a ZIP.
- 3D: GLB at true size with the materials and finishes, and GLB with USDZ for View in AR.
- For the caster: the metal as STL with Design Facts and the cast check, in the caster pack.
- Projects: a
.jewelfile with the model, materials, lighting and camera, to reopen in Jart.
More in Opening your files and Exporting stills, turntables, AR and 3D. To look inside a file without the studio, use the free 3D viewer; to change its format, the free 3DM to STL, 3DM to GLB and STL to GLB converters, which run in the browser too.
Open your own design in Jart and render it.
Open a 3DM, STL or GLB file, or a sample ring, choose the stone and the metal, and render it photoreal in your browser. No account needed.