Fillet

Status: Implemented

Fillet replaces selected edges on a single solid with a constant-radius blend generated by BREP.filletSolid.

Inputs

• edges – pick edges directly or select faces to expand into their boundary edges.
• radius – constant radius applied to every edge.
• resolution – number of segments around the fillet tube; increase for smoother large radii.
• inflate – offsets tangency curves and end caps to avoid coplanar leftovers; closed loops skip the wedge inset to avoid self‑intersection.
• direction – AUTO (default) classifies each selected edge as inside/outside and applies the corresponding boolean (INSET => subtract, OUTSET => union). You can still force INSET or OUTSET.
• patchFilletEndCaps – enabled by default; moves eligible three-face tip points and patches selected end-cap triangles.
• smoothGeneratedEdges – optional endpoint-constrained curve fitting on newly generated fillet boundary edges.
• cleanupTinyFaceIslandsArea – area threshold for relabeling tiny disconnected face islands (<= 0 disables).
• debug – keeps helper bodies visible and logs extra diagnostics.
• showTangentOverlays – adds pre-inflate tangency polylines to the helper tube for debugging.

Behaviour

• All selected edges must belong to the same solid; face picks expand to boundary edges before the builder runs.
• Helper tube/wedge bodies are generated per edge, grouped by resolved side, then applied in one unified pass: subtract all INSET tools and union all OUTSET tools.
• In AUTO, edge side is decided per edge (signed-dihedral first, inside/outside probing as fallback) so mixed inside/outside selections can run in one feature.
• Closed-loop paths suppress the wedge inset used for INSET cuts so the cutter does not self-intersect; tangency offsets still keep the fillet slightly inflated to avoid coplanar seams.
• On success the original solid is replaced by the blended result. Enabling debug leaves helper solids (and optional tangent overlays) in the scene for inspection.