Clean Mesh

AI-generated and scanned meshes often have broken geometry. When you crush them, they fall apart into fragments or stop far above the target. Clean Mesh repairs the mesh before the crush.

Turn it on with the Clean Mesh checkbox in the Cleanup section.

What it does

  • Merges duplicate vertices.
  • Removes broken faces (zero-area faces) and duplicate faces.
  • Fixes flipped faces.
  • Deletes small floating pieces (floaters).

Remove Small Pieces

The Remove Small Pieces slider sets how small a loose piece has to be to get deleted. It is a share of the mesh's triangles.

  • Default: 0.1%. Range: 0% to 5%.
  • 0% keeps every piece.
  • Greyed out unless Clean Mesh is on.

Raise it when a scan has lots of floating bits. Keep it low for models that really are made of separate parts, like a set of small screws.

Runs on its own when a mesh needs it

You don't always have to switch it on. Clean Mesh runs by itself on an object (and the report says so) when:

  • 2% or more of its vertices are duplicates. Scans from glTF, FBX and OBJ are often split along UV seams; crushing them without welding opens cracks along the seams.
  • 2% or more of its triangles have no area. This is typical of an OBJ saved with too few decimals, or a scan snapped to a coarse grid. Without cleaning, the crush would stop with "Unable to reduce mesh".

Welded meshes (most CAD parts and sculpts) score 0% and are left alone. Turn the checkbox on yourself for other broken meshes, for example flipped faces or floating debris.

Only the copy changes

Clean Mesh only changes the crushed copy. Your original is never repaired or edited.

When something was fixed, the report in the status bar lists it, for example how many vertices were merged and how many bad faces were removed.

When to use it

  • A crush ends far above the target and the report says the mesh may be broken: try Clean Mesh.
  • The crushed result has holes, spikes or fragments that the original does not.
  • The mesh comes from an AI model generator or a photogrammetry scan.

If you already have Clean Mesh on and the report still says the mesh stays above the target, the mesh cannot be reduced further without breaking its shape. See Limits.