blend_corner.rs rebuilds the planar faces at the ends of the filleted edges (three planar faces and three straight edges at each such vertex) and keeps the rest. One round at a vertex ends in the third face's exact section of its cylinder; two rounds with the third edge sharp trim each other (rolling ball: the crease from where their contact lines cross to the third edge for equal radii, else to the smaller round's contact line on the face that ends the larger one, which gets the exact section between); three rounds meet a sphere for equal radii, else a rational degree-4 patch through plane sections of the cylinders, the sections turned so that the cylinders' curvatures agree where two meet on a face and the patch fitted tangent to all three (within 0.01 degrees) and to the face at its closed corner.
kernel::fillet falls back to it when the local blends refuse: an edge that ends on an earlier round (any radius) takes the round off (delete_faces) and blends both edges together, so r3 next to r2 and a third edge into a mitred pair work. delete_faces: a gap stretch along several deleted faces keeps the corners between them (two rounds meeting in a mitre come off back to the sharp corner). splitface::fit is shared for the crease.
Tests: volumes against the strips-minus-overlap reference (exact strips, overlap integrated; checked against an independent 1D integral), the sphere-octant formula for three equal rounds, tangency along the patch, closed meshes, refusals without panics.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
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 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
For solvecraft-params' Split Face feature:
- Sketch tools are chains of Seg2. A single line splits by its plane and a
single arc by its cylinder, exactly (a circular edge on a planar face);
longer chains and splines follow the curve.
- split_faces_with_map gives the source face of each face of the result.
- A listed face the tool misses is an error naming it (split_any keeps
the lenient form for Trim).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
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 <[email protected]>
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 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
split_body(body, tool) divides every face where the tool meets it and
closes each side with the piece of the tool surface inside the body.
- Patches have outer loops and holes.
- Bands go round a cylinder or another surface of revolution.
- Each side falls apart into its connected parts.
- A body the tool misses comes back whole.
Faces that are B-spline sheets but really planes or circular cylinders
(extruded faces) split as the whole plane or cylinder: the tool is
extended, and the field is exact and cheap.
Tests (volumes): a box split by a plane (2400/3600); a holed plate split
through its hole into two equal halves; a box split by a cylinder's side
into the core (pi*16*30) and the rest; a plane that misses.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
split_faces(body, faces, tool) divides the chosen faces where the tool
meets them and leaves the solid unchanged. It handles:
- lines across a face;
- closed lines inside a face (a disc inside a ring);
- lines that run into a hole (the face is divided around it).
Edges the line ends on are cut in every face that uses them. The tool's
zero set is traced on a finely divided triangulation of the face, each
point is placed exactly on the surface by bisection in its parameters,
the ends are placed exactly on the boundary edges, and a cubic is fitted
through the points (a line when they are straight).
Tests: a box top split by a plane (areas 80/120, later booleans still
work); a cylinder side split by a sketch line; a cylinder top split in
ring and disc by a smaller cylinder's face; a plate top split through
its hole into two equal halves; a tool that misses is an error. Volume
and area are unchanged in every case.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
- IGES import (kernel iges_in, from the published specification). The file
is restated as STEP and read by the STEP reader, so an IGES file becomes
the same Import base feature.
- Manifold solid B-reps (186/514/510/508/504/502).
- Trimmed (144), bounded (143) and bare B-spline surfaces, sewn into a
solid by shared edges, with face orientation made consistent.
- Curves: lines, arcs, ellipses, composite and rational B-spline curves.
- Surfaces: planes, analytic surfaces 190-198, B-spline surfaces,
surfaces of revolution and tabulated cylinders.
- Transformations, units, colours, names (406 form 15 or labels).
Open, insert and drop .igs/.iges like STEP.
- IGES export (kernel iges_out): each body as a manifold solid B-rep on the
surfaces a STEP export uses, with name properties and colours.
ExportCommand to .igs.
- OBJ import as mesh bodies: objects/groups, polygons fanned, negative
indices, bad lines reported.
- STL: binary files whose header starts with "solid" and those with a zero
triangle count read as binary; non-finite vertices dropped; facet
normals ignored; ASCII with non-UTF-8 names. Mesh bodies get consistent
winding (stray inverted facets turned over).
- Tests: primitives and features round-trip through IGES (volume, area,
name, colour). Six trimmed patches sew into a closed box. Hostile IGES,
OBJ and STL inputs never panic. STL quirks. The engine exports a design
to IGES and opens it again. All 76 oracle parts round-trip through IGES
with matching volume (local check).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
The read-back check (fallback to unmerged pieces) imported every export.
Now it runs only when some body actually had faces merged. Oracle 41
(42 faces, nothing merged): export no longer re-imports, which saved 7 s.
Pipe flange (merges): 1.1 s for the read-back.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
- Bodies carry a Paint for export (opacity, per-face colours), set by
Document::painted from the appearance model. The paint comes from a
face appearance, a body/component appearance's opacity or a material
look (Glass), and falls back to the paint the body was imported with.
- STEP: faces with colours of their own get a STYLED_ITEM on their
ADVANCED_FACE. See-through looks add SURFACE_STYLE_TRANSPARENT.
Differently coloured pieces are not merged into one face.
- STEP import reads face styles and transparency. The reader tracks the
file face of each kernel face (bands split in two keep it), so imported
face colours land on the right faces; the design shows them through
face_colors.
- 3MF: per-triangle colours (pid/p1 into the base materials, carried
through welding) and the object's alpha (#RRGGBBAA).
- Tests: a blue half-transparent cube with a red top exports, re-imports
with its opacity and the red top face, and keeps it when opened and
exported again. 3MF writes the alpha and the face entry.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Fusion round trip WARNs on face counts:
- 48: the pulley's annular end faces arrived as 240° and 120° sectors.
- 54: the side faces and holes of a body glued to its mirror image came
in halves.
Changes:
- Planes merge: PLANE faces and flat B-spline sheets, as well as revolved
planes. A plane keeps several loops (an annulus, a face with holes), no
seam. Flat B-spline sheets are written as PLANE.
- Pieces of an extruded cylinder (B-spline sheets) merge when their edges
are circles square to the axis. The merged face is written as a
CYLINDRICAL_SURFACE, with its parameter seam on the face's seam edge.
- A full turn's loop is built explicitly: ring, seam, other ring (or the
apex on the axis), seam back. Before, it depended on edge order, and
after 81c85b5 the pulley's last pieces no longer merged.
- The read-back check moved to the whole file. If the merged file reads
with warnings and the unmerged one does not, the unmerged one is
written.
Results: 48 has 12 faces (Fusion 12), 54 has 12 (Fusion 12). Oracle
results are unchanged (73 PASS) and the STEP corpus passes 76/76. New
test: a plate with a hole glued to its mirror exports 8 faces, all
planes and cylinders, and round-trips.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
truck's connected components came out in hash order of face addresses, so a
boolean's faces, and everything built on them (fillet bands, STEP entity
order), changed from run to run. That made the oracle 35 export differ run to
run. Its old step_export flakes came from the orientation check's drifting
search, removed in 2db9e66. The result's shells and faces now keep the
order of the shell they come from (vendored truck-shapeops). Oracle results
are unchanged (73 PASS before and after). Test: the tee of oracle 35 with its
junction fillet exports byte-identical three times in one process (it failed
before).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
With solvecraft-repo's curved-edge fillets (d72ec38), oracle 40's torus
groove comes out of truck in three pieces. Merging them made a band round the
torus whose single loop crosses itself, and the reader could not lay it out
("unsupported seam loop layout (2 runs)"). Each body's merged B-rep is now
read back. If that gives warnings and the unmerged pieces read cleanly, the
pieces are written instead.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Free-form strips (a curved-edge fillet's B-spline bands round a saddle) vary
their normal too much along the loop for the loop-direction test, and the
hinted nearest-parameter search drifted on them: false 'runs clockwise'
reports on faces that round-trip exactly. The check now covers cylinders,
cones, spheres and tori (closed surfaces, where a loop read the wrong way
silently gives the rest of the surface); volume checks cover the rest. It
still flags all 8 sphere corners of a fillet box with their sense flipped.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
- Surfaces of revolution follow ISO 10303-42 strictly in reader and writer: the
normal is d/d(angle) x d/d(profile), the opposite of truck's revolution, as
Fusion reads it (fixes Fusion inverting fillet sphere corners and the dimple).
step_orientation_errors flags faces whose loop runs clockwise round their
normal; engine, oracle and kernel round trips assert it.
- Revolved faces with analytic profiles are written as native PLANE,
CYLINDRICAL/CONICAL/SPHERICAL/TOROIDAL surfaces, and the pieces truck splits
a revolution into are merged back into one face per surface (with a seam
edge for full turns), so face counts match other systems.
- A horn torus (tight sweep: tube touching its axis) is written as one rational
B-spline face whose loop passes the pole twice, with truck's zero-length pole
edges collapsed, instead of a degenerate surface of revolution; the reader
starts such figure-eight loops off the pole (Fusion's own part 50 now imports
with the right volume).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
