create_shape() returns a Python-owned Element (SWIG_POINTER_OWN in the
boost::variant out typemap). Its .geometry property calls Element::geometry(),
which returns a reference into the element's boost::shared_ptr<Representation>
_geometry member. SWIG wraps that reference as a non-owning pointer, so the
returned Triangulation/BRep/Serialization proxy does not keep the element alive.
When a caller keeps only .geometry (e.g. create_shape(s, e).geometry) and drops
the parent element, Python garbage-collects the element, destroying its
shared_ptr and freeing the underlying representation. Subsequent reads of
verts/faces then return freed memory: empty or implausible float/int garbage,
non-deterministically depending on GC and allocator timing. This is silent data
corruption, not a crash, and has bitten users since 2020.
Fix: in the TriangulationElement/SerializedElement/BRepElement pythoncode, wrap
the geometry getter so the returned geometry stores a backreference to its
owning element (result._parent = self). This makes the parent's lifetime at
least as long as the geometry's, automatically and transparently, so no caller
has to remember to hold the element. This is aothms's suggested backreference,
applied generically in the binding rather than left as a workaround.
Reproduced deterministically (washBasin fixture): before, verts len 0 vs 133500
across repeated GC-pressure runs; after, 133500 every run for all three element
types. test_create_shape passes; no regressions.
Note: tree.select_ray()'s ray_intersection_result (2024 follow-up in #1124) is a
separate ownership mechanism (std::vector element reference + std::array member
pointer) and is left as follow-up scope.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
(cherry picked from commit 824c1fc280)
Ports the 7-commit v0.8.0 SVG edge-classification feature (f0970b90b +
6 follow-ups) onto wgpu's heavily-diverged serializer. Reconstructed
block-by-block rather than merged, because both sides rewrote
SvgSerializer (v0.8.0 +419, wgpu +778) and git's conflict alignment was
misleading.
Key wgpu adaptations reasoned per block:
- IfcUtil::IfcBaseEntity* (pointer identity) -> express::Base (value),
incl. as a std::map key in draw_hlr (express::Base has operator<);
nullptr fallback -> express::Base{}
- boost::optional -> std::optional (css_class, dash_array)
- hlr_calc::result_type pair -> 3-tuple (adds per-edge class label)
- draw_hlr restructured with a group_by_product map: ONE path_object per
product so multiple class buckets share a group and per-path classes
survive Bonsai's merge (NOT naive per-item threading, which fragments
groups -- caught during visual verification)
- settings wired into wgpu's apply_settings() (ctor-called), NOT the
feature's added ready() call which wgpu already solved differently
- logger_.Warning -> logger().warning in write(geometry_data)
Verified end-to-end via IfcConvert on a curved-geometry stress scene
(Suzanne/Torus/Sphere/Cube/Cone/...): edges classify into outline/sharp/
crease/boundary/flush with correct per-product grouping and CSS styling.
Requires the model's storey to carry an Elevation and --svg-project to
trigger the HLR projection.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- `function_item`, `tags` added in df7318973
- MakeVolume added in c385b93, ignore as all other conversion settings
- moved `SeparateZUpNode` ignore to the other geom serializer settings
Petru Conduraru