New kernel file blend_variable.rs. The hooks into blend.rs are visibility
only: plane_normal, vtx, rebuild_face and unsupported are now pub(crate).
- fillet_variable(body, edge, start, r0, r1) works on the same edge
configuration as the constant fillet (straight edge, planar faces, end
faces square to it). The radius runs linearly from the end nearest
`start`, and every section square to the edge is a circular arc. The
blend is an exact degree (2, 1) rational B-spline: arc control points
move linearly.
- fillet_chord(body, edges, chord): the radius per edge comes from its
face angle (chord = 2 r cos(phi/2)).
Fillet feature: style constant | chord | variable {radius2, start};
FusionFilletEdgesCommand takes type, radius2 and start.
Tests:
- Variable 2 -> 5 on a box edge removes (1 - pi/4) L (r0^2 + r0 r1 + r1^2)/3.
Starting from the other end gives the same solid; equal radii give the
constant fillet; too large is refused.
- Chord 4 on a right angle equals radius 4/sqrt(2).
- Engine: both types by command.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Kernel extend(body, edges, distance) moves the picked straight edges of a
planar surface outward in its plane, with neighbours meeting them. Doc
feature SurfaceExtend, engine FusionExtendCommand. Tests: 10x10 extended
by 5 past one edge gives 150, past two gives 225; the engine patch, trim,
extend and thicken gives 240.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Kernel (surfaces):
- Bodies with an open shell are surface bodies (Body::is_surface).
- patch_region: a planar patch of a sketch region. patch_edges: a planar
patch filling a closed loop of a body's edges.
- copy_faces: faces copied out as a surface.
- stitch: sew surfaces along coinciding edges, turning faces to agree; the
result is a solid when it closes.
- trim: cut a surface by a plane or face and keep one side.
- thicken: offset planar and circular-cylindrical faces along their
normals (one side or symmetric) into a solid. Plane copies slide;
cylinder copies scale about the axis, exact for NURBS circles. Free
edges get ruled walls. Faces meeting at a sharp edge are refused.
Doc features Patch, Stitch, Thicken (with operations) and SurfaceTrim;
engine commands FusionSurfacePatchCommand, FusionSurfaceStitchCommand,
FusionSurfaceThickenCommand and FusionSurfaceTrimCommand.
Tests (volumes):
- A 10x10 patch thickened by 2 gives 200, also symmetric.
- Half a cylinder side thickened outward gives half a ring; both halves
inward give the full ring.
- Six faces of a box stitched back give 6000; an open box with its top
patched from the edges, stitched, gives 6000.
- Trim keeps 30 or 70 of 100.
- Engine: patch, trim, thicken gives 140.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
