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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
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 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Meshing (vendored truck-meshalgo) works within a budget so hostile files
cannot hang: bounded edge and surface divisions (point caps, depth and
round limits, NaN-safe), and a grid budget per face shared out per shell.
Surface grids refine only the direction that bends; rulings left undivided
get cells comparable to the other direction, so trimmed cylinders (holes,
tee joints) no longer lose volume to long triangles. The helical sweep
imports in 12 s instead of 7 minutes.
Small sphere patches get poles away from them even when the file runs a
seam through the patch (a pyramid's corner blend). Faces the mesher cannot
mesh are reported as import warnings. Test: wild B-spline and far-off
boundaries import in bounded time.
STEP corpus 65/66 (50-sweep-tight-bend: a horn-torus bend whose inner side
collapses to a point; Fusion's own area for it is also off).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Our writer assembles the file: AP242 header and contexts, a product per part
(or per component, with NEXT_ASSEMBLY_USAGE_OCCURRENCE and item-defined
placements per occurrence), named solids, surface colours as styled items,
ADVANCED_FACE for advanced breps. truck now writes only each body's B-rep,
which we copy in; identical geometric entities are written once and shared.
Designs with components export as assemblies (bodies in component frames).
step_validate also rejects unreferenced non-root entities. Tests: the sample
plate and a component assembly export, validate and read back with no
warnings and the same volume, area and face counts; the oracle replay checks
area and faces too (39 rebuildable cases pass). An independent Part 21
parser (step-p21, run outside the repo) accepts our exports.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
Vendored truck-stepio (writer only): an intersection curve's second surface
was written at the first one's id (duplicate ids for every boolean edge),
and revolved surfaces lost their orientation (the modeling-surface sense was
always true; inverted or mirrored revolutions came out inside out). Export
now writes intersection edges as C1 cubic B-splines through exact points,
so files carry plain 3D curves and no redundant surfaces.
Vendored truck-meshalgo: hinted parameter searches that run off a B-spline's
domain are rejected or clamped (meshing their grid never finished).
STEP import: straight revolution profiles are bounded in the meridian plane
and stop at the axis; loops on revolutions start away from the axis; face
extents include edge end points. Edges between pieces of one split surface
draw as seams.
kernel::step_validate checks a STEP file (duplicate ids, dangling
references, dense numbering); the oracle replay now exports every rebuilt
part, validates it and re-imports it with no warnings and the same volume
(all 32 rebuildable cases pass).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
