Cross-Technology BIM Workflows

Scope: End-to-end workflows combining IfcOpenShell, Bonsai, and Blender Dependencies: ifcos-impl-creation, bonsai-core-architecture Version coverage: Blender 3.x-5.x | IFC2X3/IFC4/IFC4X3 | Bonsai v0.8.x

Critical Warnings

1. ALWAYS determine the execution context first: standalone Python (IfcOpenShell only) vs Blender Python (bpy available) vs Bonsai-loaded (IfcStore available). The API surface differs per context.
2. ALWAYS use ifcopenshell.api.run() for IFC mutations in ALL contexts. NEVER modify IFC entity attributes directly — this bypasses relationship management and breaks graph integrity.
3. ALWAYS call bpy.ops.bim.edit_object_placement() after modifying a Blender object's location/rotation/scale when Bonsai is active. Blender transforms do NOT auto-sync to IFC.
4. NEVER mix IfcStore.get_file() (Bonsai context) with ifcopenshell.open() on the same file simultaneously. Bonsai owns the in-memory IFC graph — opening a second handle creates divergent state.
5. NEVER use blenderbim.* imports. The package was renamed to bonsai.* in v0.8.0 (2024).
6. ALWAYS set up units (unit.assign_unit) and geometric contexts (context.add_context) before creating any geometry. Geometry without context or units is ambiguous and may render incorrectly.
7. NEVER use void.add_opening() in Bonsai v0.8.0+. Use feature.add_feature() instead.

Decision Tree: Choose Your Execution Context