What happened?
Hollow pipe elbows (CODO - Spanish for elbow) exported from Tekla Structures as IFCREVOLVEDAREASOLID entities render with incorrect positioning in web-ifc and ThatOpen Fragments viewers. The same geometry renders correctly in Trimble's IFC viewer, confirming the IFC file is valid.
What works:
- ✅ Straight pipe sections (IFCBEAM with IFCEXTRUDEDAREASOLID) render correctly
- ✅ Weld points (IFCFASTENER with IFCFACETEDBREP) render correctly
- ✅ Handrail structure and supports render correctly
- ✅ Trimble Tekla viewer displays all elbows in correct positions
What fails:
- ❌ All 4 hollow elbows (IFCREVOLVEDAREASOLID) positioned incorrectly
- ❌ Elbows appear displaced from expected locations
- ❌ Error consistent in both direct web-ifc parsing and Fragments conversion
- ❌ Issue NOT related to coordinate normalization
Root Cause: Incorrect transformation matrix calculation for IFCREVOLVEDAREASOLID when placed in nested assembly hierarchy with oriented coordinate systems.
Version
0.0.77
What browsers are you seeing the problem on?
No response
Relevant log output
No console errors - the issue manifests as incorrect 3D positioning:
- IFC entities parse without errors
- Geometry calculates without warnings
- Output positioning differs from Trimble viewer reference implementation
Anything else?
Test Case Details
Environment:
- Source: Tekla Structures 2024 SP5 IFC4 export
- Schema: IFC4 DesignTransferView
- Geometry Type: IFCREVOLVEDAREASOLID (hollow circle profile)
- Placement: Nested in IFCELEMENTASSEMBLY with oriented coordinate systems
The 4 Affected Elbows:
- Entity # 1141 - Shape # 1132 at placement # 1126
- Entity # 1245 - Shape # 1132 at placement # 1240
- Entity # 1368 - Shape # 1362 at placement # 1357
- Entity # 1447 - Shape # 1362 at placement # 1442
Related Issues:
Proof of Valid IFC:
Same file renders correctly in Trimble Tekla IFC viewer → bug is in web-ifc transformation matrix calculation
Test File: See attachment
out_ds.zip
What happened?
Hollow pipe elbows (CODO - Spanish for elbow) exported from Tekla Structures as IFCREVOLVEDAREASOLID entities render with incorrect positioning in web-ifc and ThatOpen Fragments viewers. The same geometry renders correctly in Trimble's IFC viewer, confirming the IFC file is valid.
What works:
What fails:
Root Cause: Incorrect transformation matrix calculation for IFCREVOLVEDAREASOLID when placed in nested assembly hierarchy with oriented coordinate systems.
Version
0.0.77
What browsers are you seeing the problem on?
No response
Relevant log output
Anything else?
Test Case Details
Environment:
The 4 Affected Elbows:
Related Issues:
Proof of Valid IFC:
Same file renders correctly in Trimble Tekla IFC viewer → bug is in web-ifc transformation matrix calculation
Test File: See attachment
out_ds.zip