fixing STL files using opencascade

[hrgdavor]

I have STLs that report non manifold vertices or get broken in prusa slicer. I have noticed that there is shape healing, https://dev.opencascade.org/doc/overview/html/occt_user_guides__shape_healing.html

... and I am wondering if I could use opencascade to try to fix some of them.

[donalffons]

Hey!
I personally haven't used any of OpenCascade's shape healing functions, but I would definitely be interested to hear about your experiences, in case you're giving it a shot.

I have used BRepBuilderAPI_Sewing in OpenCascade.js before, for loading tessellated 3D geometries and attempting to convert them into solids. That approach did seem to work ok, at least with my limited testing. My approach with BRepBuilderAPI_Sewing was this:

1. Construct a TopoDS_Compound and throw all the individual triangles (constructed as BRepBuilderAPI_MakeFace from BRepBuilderAPI_MakePolygon from BRepBuilderAPI_MakeVertex) into it.
2. Create a BRepBuilderAPI_Sewing, set your desired tolerances and ::Load() the compound
3. Run ::Perform() on the sewing instance.
4. Get your sewed shape via ::SewedShape()

The shape healing approach seems to offer much more fine-grained control than my simplistic attempt.

[hrgdavor]

found this git repo just today, and I am curious about the healing functions. I might have few more noob questions to get the basic script working.

Thanks for the hints, much appreciated, also thanks for the quick reply.

[donalffons]

Feel free to shoot your questions! I'll try to help.