Mesh2Solid Beta

What it does

Built for machined and 3D-print parts: bores, pins, shafts, fillets, chamfers, countersinks, threads. Whatever the mesh holds of those comes back as real geometry; curved regions that fit none of them (non-circular fillets, lofts, spline contours) become smooth freeform surfaces, and the rest stays planar. The body always closes. Organic shapes and scan data work, but end up mostly freeform.

• Real geometry, not a triangle cloud: A bore stays a bore — the add-in fits cylinders, cones, tori and spheres to the facets, with exact circle and arc edges, and builds a solid from them. Measure, fillet and cut against it like any other body
• Threads (Pro): Helical threads are rebuilt as helix faces on their ideal profile, run-out included. With Threads as Fusion threads they become plain cylinders with a Fusion cosmetic thread in the matching ISO metric size (class 6H/6g) instead; a thread without an ISO size keeps its helix faces
• Freeform where nothing else fits (Pro): Leftover curved facets become B-spline surfaces within the distance tolerance, so a logo contour or a lofted edge comes out smooth instead of as dozens of strips
• Mesh body or STL file: Pick a mesh body in your design and the solid is added right next to it, mesh switched off. Pick nothing and you get a file dialog — the STL opens as a new document
• Choose what gets detected: Cylinders, cones, tori, spheres, threads and freeform each toggle on and off; what is switched off stays planar. Distance and angle tolerance decide how closely a surface has to follow the facets
• Reduce very fine meshes: The built-in slider runs Fusion's adaptive reduce before detection — fine meshes take longer and are rarely more accurate

How to use it

1. Run Mesh to Solid from Solid → Modify
2. Select a mesh body — or leave the selection empty to pick an STL file instead
3. Check the triangle count shown, and drag Reduce to left if the mesh is fine
4. Set distance and angle tolerance (defaults: 0.05 mm and 2°), pick the shape types — all on by default — and click OK

Above 200,000 triangles conversion and import take minutes — the reduction slider starts there and the dialog warns above it. If the body does not come out closed, a message says so.

Installation

Mesh2Solid is an add-in (not a plugin bundle) and goes into the AddIns folder:

macOS

1. Quit Fusion 360
2. Unzip and copy the Mesh2Solid folder to
   ~/Library/Application Support/Autodesk/Autodesk Fusion 360/API/AddIns/
3. Start Fusion 360 — enable the add-in under Utilities → Add-Ins

Windows

1. Quit Fusion 360
2. Unzip and copy the Mesh2Solid folder to
   %APPDATA%\Autodesk\Autodesk Fusion 360\API\AddIns\
3. Start Fusion 360 — enable the add-in under Utilities → Add-Ins

The detection core ships as a native library: macOS on Apple Silicon and Windows on x86-64. Intel Macs are not supported.