OBJ to STEP: turn an OBJ mesh into an editable CAD solid
Last updated by the stl2step team
stl2step converts OBJ files to STEP by rebuilding the mesh as real CAD faces (planes, cylinders, cones, spheres, tori and B-splines) sewn into one closed solid. Upload the .obj, check the faces in the 3D viewer and download the .step; the first 3 conversions are free.
What happens to an OBJ file
- Polygons are triangulated. Quads and n-gons are split into triangles before the conversion; the faces of the result don't depend on how the OBJ was polygonized.
- Materials, textures and UVs are ignored. Only the geometry is converted. A STEP solid has no texture.
- All objects in the file are converted together. Together they have to form one closed surface; export a single object if the file holds a whole scene.
- Size limit: 150,000 triangles after triangulation and 50 MB per file.
Which OBJ files convert well
Mechanical parts exported from CAD or modeled with hard edges in Blender, 3ds Max or Maya come back mostly as planes, cylinders and other analytic faces. Sculpted and organic models also convert, but most of their area becomes smooth B-spline faces, which is the right surface type for them.
Questions
Can I convert OBJ to STEP for free?
Yes. New accounts get 3 free conversions with the STEP download.
Does stl2step keep OBJ colors or textures?
No. STEP solids carry geometry only, so materials, textures and UV maps are ignored.
My OBJ has quads. Is that a problem?
No. Quads and n-gons are triangulated automatically before the conversion.