Ideas from ScanRuler for reverse engineering and mesh to solid

[tdslot]

Summary

ScanRuler by CNC Kitchen is a browser-based tool for measuring and reverse engineering 3D scans. Its scope overlaps with what SolidCraft could do for reverse engineering and mesh to solid work, so it is a good source of ideas.

Licence note

ScanRuler is AGPL-3.0 and the owner offers a separate commercial licence. SolidCraft should take ideas and workflows only, not copy code, unless the licence question is settled first.

Ideas worth borrowing

1. Reverse engineering from a scan

• Sketch on a section through the scan. A "Fit all chains" action reads the slice as lines and arcs. Constraints and dimensions then hold the sketch.
• Extrude or revolve the sketch, then add fillets, chamfers, shells, holes, threads, drafts, mirrors, patterns, lofts and sweeps.
• Freeform parts are modelled from surfaces fitted to the scan, or from a network of B-spline patches drawn over it.
• Compare in Deviation checks the modelled bodies against the scan.

2. Primitive fitting (mesh to analytic geometry)

• Click a feature and get a fitted sphere, cylinder, cone, torus, plane or circle. The fit reports its σ and form error.
• The surface around the click is picked automatically, or marked by hand with a brush, window or lasso.
• Fitted elements become points, lines and planes that can be dimensioned. This is the missing link between a mesh and clean CAD faces.

3. Alignment

• Guided 3-2-1 datum alignment.
• Auto-align read off the scan's own faces.
• Symmetry-plane alignment.

4. Deviation analysis

• Load the nominal part (mesh or STEP), auto-align, and paint the signed deviation on the scan.
• Hover to read a value, click to pin one.
• Find volume errors lists whole regions of extra or missing material.
• Compare against one fitted element ("is this face flat, is this bore round?").

5. Mesh Tools

• Remove islands, flip normals, cut at a plane, fill holes, smooth, shrink/expand, shell/hollow.
• Edits land on a copy of the scan, which can be measured against the original.
• Reduce mesh to a light mesh within a set tolerance of the scan.
• Booleans against fitted cylinders or modelled bodies.

6. Section and 2D tools

• Cut a section across any element.
• A shadow section gives the widest outline, useful for bins, foam cutouts and pockets.
• Export the 2D sheet at true scale as SVG, DXF or CSV.

7. Wall thickness

Ray or sphere casting over the mesh, with thin walls shown in red. It needs no reference part.

8. Smaller things

• GD&T checks (flatness, parallelism, perpendicularity, coaxiality).
• STEP export of measured geometry as analytic faces.
• A project file that keeps the whole session.
• An MCP server for agent control (we already have agent chat).

Suggested priority for SolidCraft

1. Primitive fitting from mesh (2).
2. Section to sketch to feature (1).
3. Mesh clean-up and reduce (5).
4. Deviation map (4), then wall thickness (7).

Would any of these fit the roadmap? Which would you want first?