Scan-to-CAD

From a 3D scan to editable parametric CAD

An STL is a mesh of triangles: fine for printing, not for precise edits. reverse3d cleans the scan, measures it, recognizes its planes, cylinders and spheres, and writes a parametric model you can edit.

Install for freeView on GitHub

The problem

  • Scans come with noise, holes and loose fragments.
  • Changing an STL (a hole, a thickness) is nearly impossible without CAD.
  • Rebuilding the part from scratch in CAD takes hours.

What you get

  • Repair: loose fragments, holes, normals, Taubin smoothing and decimation.
  • OBB/PCA alignment and real scale.
  • Detected primitives with their parameters (radii, axes, normals).
  • cad.scad and cad.py ready to edit.

How to do it with your AI agent

  1. 01

    Repair

    Clean and align the scan.

    “Repair scan.stl and align it to the axes.”

  2. 02

    Measure

    Dimensions, area, volume and watertightness.

    “Measure scan.stl and tell me if it is watertight.”

  3. 03

    Convert

    Primitives and parametric code in one recipe.

    “Turn scan.stl into parametric OpenSCAD and CadQuery CAD.”

From the terminal

reverse3d run scan_to_cad scan.stl output/

Start in 1 minute

Paste this sentence into Claude Code, Cursor, Copilot, Gemini CLI, Codex or Windsurf:

Install reverse3d from https://github.com/rellytechgame/Reverse3D-tool following its AGENTS.md. You have my permission to run the installer; don't ask me any questions.

Frequently asked questions

Which formats does it accept?

STL, OBJ, PLY, GLB, glTF and OFF meshes; PLY, XYZ and PCD point clouds.

Does it work with any shape?

It works best with mechanical parts (planes, cylinders, spheres). Organic shapes are repaired and measured, but not reduced to primitives.

Can I use it without an AI agent?

Yes, from the terminal: reverse3d run scan_to_cad.