3D scan to CAD: turn a scanned mesh into a STEP solid
Last updated by the stl2step team
To turn a 3D scan into CAD, export the scan as a closed mesh, convert it to a STEP solid with real faces, and finish it in your CAD program. stl2step automates the conversion: it fits planes, cylinders, cones, spheres, tori and B-splines to the mesh and sews them into one solid in minutes.
From scan to CAD in 5 steps
Scan and mesh the part
Export a mesh (STL, OBJ or PLY) from your scanner or photogrammetry software, not a point cloud.
Clean the mesh
Remove the turntable, fixtures and floating noise, fill holes so the surface is closed, and smooth lightly. The cleaner the mesh, the more faces come back as exact planes and cylinders.
Reduce it
Decimate to at most 150,000 triangles. Keep detail where edges and small features are.
Convert with stl2step
Upload the mesh, check the faces and surface types in the viewer, and download the STEP solid.
Finish in CAD
Open the STEP, check critical dimensions against the real part, and adjust faces with direct-modeling tools where the scan was poor.
What to expect from scanned data
stl2step is measured on meshes exported from CAD, where vertices lie exactly on the original surfaces; there it recovers 97.9% of faces (benchmark). Scans add noise and holes, so flat and cylindrical regions come back as analytic faces where the data supports it and as smooth B-splines elsewhere. Dimensions are as accurate as the scan itself.
Scan to CAD options compared
Dedicated reverse-engineering suites let an expert fit surfaces and features region by region, with full control and a feature tree, in 30 minutes to hours per part. stl2step does the surface recovery automatically in minutes and gives you a solid to finish in your own CAD program. See every method compared.
Questions
Can I turn a 3D scan into a CAD model automatically?
Yes, as a solid with exact faces: mesh the scan, close it, and convert it with stl2step. You get a STEP to finish in CAD, not a feature tree.
Does stl2step accept point clouds?
No, it needs a mesh. Reconstruct a mesh from the points first (for example screened Poisson reconstruction), then convert it.