Mesh Processing (Scan Cleanup)

Clean, decimate, repair, and retopologize the raw mesh that comes out of a scanner.

The cleanup layer between a raw scan and a usable asset. Scans arrive noisy, holey, oversized, off-axis, with floating artefacts and inconsistent normals — this is where you fix it. Pairs with Photogrammetry Software and Handheld 3D Scanners (where the meshes come from), Mesh Retopology (when you need clean quads), Point Cloud Tools (for upstream point-cloud work), Scan-to-CAD / Reverse Engineering (for parametric output), and Mesh Repair & Conversion (for the 3D-print-flavored cleanup of broken STLs).

OSS heavyweights

★ MeshLab — free, OSS (GPL); the workhorse. Decimation (Quadric Edge Collapse), smoothing, hole filling, normal recompute, alignment (ICP), texture transfer, screened Poisson reconstruction. CLI mode for batch jobs. Cross-platform. The default FOSS mesh-processing app.
★ Blender — free, OSS (GPL); not a scanner-specific tool but the most-used "open it in Blender and fix it" app. Sculpt mode + Dyntopo + Remesh modifier + 3D-Print Toolbox add-on covers most scan cleanup. See 3D & Spatial Design Tools.
★ CloudCompare — free, OSS (GPL); point-cloud-first but excellent for mesh / cloud comparison, registration (ICP), and distance maps. See Point Cloud Tools.
Open3D — free, OSS (MIT); Python library; point clouds + meshes; algorithmic cleanup in scripts.
Instant Meshes — free, OSS (BSD); fast quad retopology; see Mesh Retopology.
PyMesh / trimesh / MeshLib (Python) — free OSS Python libs for scriptable mesh ops.
libigl — research mesh library; MPL2.

★ Meshmixer (Autodesk) — free closed source; abandoned 2021 but still distributed and still works on Win / Mac. Brilliant selection-based smoothing, hole filling, hollowing, lattice generation. The "I can't believe this still gets used in 2026" tool.
Microsoft 3D Builder — free, Windows; one-click STL repair; great for quick fixes. See Mesh Repair & Conversion.
NetFabb Free (Autodesk) — discontinued, but the online repair service still backs PrusaSlicer's "Fix through Netfabb".

ZBrush — paid (Maxon); the sculpting / scan-cleanup pro pick; ZRemesher for retopology, DynaMesh, decimation master.
3D-Coat — paid; mesh sculpt + retopo + texture.
Mudbox (Autodesk) — paid; sculpting.
Geomagic Wrap — paid (3D Systems); pro mesh-cleanup for scan data; the scan-shop standard.
Geomagic Design X — paid; scan-to-parametric. See Scan-to-CAD / Reverse Engineering.
Rhinoceros 3D — paid; mesh + NURBS hybrid; QuadRemesh built in.
3-matic (Materialise) — paid; medical / dental / industrial; precision mesh editing.

Decimation / simplification — MeshLab Quadric Edge Collapse, Blender Decimate modifier, gltf-transform's simplify (for web).
Hole filling — MeshLab "Close Holes", Blender F-fill, Meshmixer "Inspector".
Smoothing / denoising — MeshLab Laplacian / Taubin, Blender smooth modifier, Meshmixer.
Alignment / registration (ICP) — CloudCompare, MeshLab "Align".
Reorienting normals — MeshLab "Re-Orient all Faces Coherently", Blender "Recalculate Outside".
Boolean / cutting — Blender (with Manifold backend in newer builds), manifold lib, Meshmixer's "Plane Cut".
Mesh-to-mesh distance — CloudCompare; the inspection workflow.
Voxel remesh / make-solid — Blender Voxel Remesh, Meshmixer "Make Solid".
Texture baking after retopology — Blender, xNormal (free), Substance.

MeshLab CLI (meshlabserver) — run .mlx filter scripts on folders.
trimesh / Open3D / PyMesh in Python — automate per-file cleanup.
gltf-transform CLI — for web-targeted glTF / GLB cleanup; see 3D Format Converters.

Default FOSS power tool: MeshLab (technical) or Blender (artist-friendly).
Quick STL repair before printing: see Mesh Repair & Conversion.
Scan cleanup before retopo: Meshmixer (still!) or Blender sculpt + remesh.
Pro / production scan-shop pipeline: Geomagic Wrap or ZBrush.
Scripted batch cleanup: trimesh + MeshLab CLI.
Need quad output: see Mesh Retopology.
Compare two scans for change / inspection: CloudCompare; see Scan Quality & Inspection.