How to convert 3MF to OBJ
- Drop your
.3mffile above. - Choose OBJ. Set Up axis to Z up for slicers or Y up for Blender, Unity, Unreal and most 3D tools.
- Download the ZIP. It contains the
.objand its.mtl; keep them in the same folder.
What ends up in the OBJ
- One OBJ object (
o) per 3MF object and one group (g) per part. - One material per colour: filament colours from Bambu Studio, OrcaSlicer and PrusaSlicer projects, or material and per-triangle colours from standard 3MF.
- Coordinates in millimetres, so a 20 mm cube stays 20 units wide.
Need a single file with colours for the web or a game engine? GLB is usually easier than OBJ + MTL.
Frequently asked questions
Does OBJ keep the colours from my 3MF?
Yes, as solid colours per part or per triangle, written to the MTL file. Textures and colours painted with the slicer's paint brush are not converted yet.
Why does my OBJ lie on its back in Blender?
3D printing files are Z-up, Blender expects Y-up OBJ files. Choose Y up before downloading, or rotate 90° on import.
What units does the OBJ use?
Millimetres, the same as the 3MF. In Blender, a 20 mm part imports as 20 units; set the unit scale to 0.001 if you work in metres.
Can I convert OBJ back to 3MF?
Yes, drop the OBJ (and its MTL) on the STL to 3MF page and export 3MF.