Is this a complete self-intersection repair?

No. It removes every triangle involved in an intersection and keeps a simple hole fill only when the result stays clean. It does not split triangles at intersection curves or reconstruct the intended solid. Complex cases may remain open or lose geometry.

Why was the hole fill rejected?

The fill was tried and then reverted because the filled mesh had self-intersections or non-manifold edges again. The output is the manifold removal-only mesh; use fill-holes or CAD if the remaining openings need closure.

Will the repaired model be watertight?

Not necessarily. Removal-only output is manifold at its edges but can have boundary edges. Check the reported boundary count and run manifold-check; a watertight result is more likely on small, localized intersections.

Why does the tool say no self-intersections were found?

The triangle-pair test did not find a crossing or coplanar overlap under its tolerance. Adjacent triangles that share a vertex or position are treated as contacts and are not reported.

Does it upload the mesh?

No. Parsing, intersection tests, face removal and the binary STL writer all run in the local Worker.

Mesh repair/Topology

Self-intersection repair (local)

Remove self-intersecting faces locally and close holes only when the closure stays safe. The Worker parses STL, OBJ, PLY, 3MF, GLB, or glTF, removes every triangle involved in an intersection, cleans the remaining mesh, and tries a simple hole fill that is reverted if it reintroduces self-intersections or non-manifold edges.

ReadyNo uploadWorkerSTL · OBJ · PLY · 3MF · GLB · glTF

Tool facts

Formats: STL · OBJ · PLY · 3MF · GLB · glTF
Output: Mesh file
Worker: Yes
Max file: 500 MB
Runs: in your browser

Why local

Self-intersection repair

No upload

Self-intersection repair

Removes intersecting faces conservatively; this is not a voxel or CSG reconstruction. Check the result before printing.

Drop a self-intersecting mesh

STL, OBJ, PLY, 3MF, GLB, or glTF. The Worker removes every triangle involved in an intersection, then fills simple holes only when the fill stays free of self-intersections and non-manifold edges. Limited to 200,000 triangles.

STL · OBJ · PLY · 3MF · GLB · GLTF

Drop a self-intersecting mesh

Choose a file

Max file size: 500 MB · No upload

No upload · File.slice() / ArrayBuffer → Worker → repaired STL.

How it works

1
Drop a mesh file in any supported format.
2
The Worker welds vertices, checks that the mesh is under the 200,000-triangle analysis cap, and tests non-adjacent triangle pairs.
3
Every triangle involved in at least one intersection is removed; the remaining mesh is welded and cleaned again.
4
Simple boundary loops are filled only if the filled result has no self-intersections and no non-manifold edges. Otherwise the fill is reverted and the removal-only mesh is kept.
5
Download the repaired binary STL and verify the reported boundary edges and self-intersections.

What the numbers mean

removal

A triangle involved in any intersecting pair is removed, including the unaffected part of that triangle. This is a conservative face-removal strategy, not a split-and-stitch reconstruction. Removing faces can delete intended geometry.

safeFill

After removal, simple boundary loops are fan-filled. The fill is kept only when the result has zero self-intersecting triangles and zero non-manifold edges. If the fill fails, the output keeps the open removal-only surface and is reported as rejected.

results

The report shows intersecting pairs and triangles before and after, the number of removed faces, boundary edges after repair, holes filled, and whether the fill was applied or rejected. A rejected fill means the output is manifold at the tested edges but may not be watertight.

Limits

Analysis is capped at 200,000 triangles. Removal can leave large openings on complex self-intersections. The tool does not perform voxel remeshing, CSG reconstruction, or split triangles along intersection curves.

Printing notes

Check the boundary-edge count before printing; a rejected fill can leave an open surface that a slicer may not close.
Run manifold-check after repair to confirm edge and vertex topology.
Use fill-holes for simple openings that remain after removal, then re-check the result.
For a complex self-intersection, repair in CAD, use a voxel remesh, or split the model into simpler parts.

Questions

References

· ISO/ASTM 52900
· Mesh self-intersection and manifold repair