- 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
- 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
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
Own ISO 10303-21 parser and AP203/AP214/AP242 geometry reader in the kernel
(step_import): planes, cylinders, cones, spheres, tori, B-spline and rational
surfaces, surfaces of revolution/extrusion; lines, conics, B-spline curves;
breps with voids, faceted breps, shell models; units (SI prefixes, conversion
based), product names, colours, assemblies (NAUO + item-defined
transformations, mapped items). Hostile input is capped and guarded; faces
that cannot be read are left out and reported. Faces that wrap around a
closed non-periodic direction (pipe tori, revolved B-spline bands) are split
for truck's mesher. Bodies are meshed per shell so open imports never panic.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
