Richard Brice 4374c81981 Honour IfcAxis2PlacementLinear Axis/RefDirection in the loft builder (#9408)
* Honour IfcAxis2PlacementLinear Axis/RefDirection in the loft builder

make_loft() (src/ifcgeom/infra_sweep_helper.cpp), shared by
IfcSectionedSolidHorizontal and IfcSectionedSurface, mishandled a cross
section's IfcAxis2PlacementLinear in two ways:

1. A placement carrying Axis but no RefDirection was placed with a fixed
   [e_y | e_z | e_x] world-axis permutation that ignored the directrix.
   On any directrix not running along +X (e.g. a north-south road
   pavement, or anywhere along a curve) the profile came out mis-oriented
   or collapsed to a sliver.

2. When two adjacent CrossSectionPositions used direction vectors
   inconsistently (a raked RefDirection at one, a plain Axis at the
   other) make_loft() logged GEO 42, dropped the rotation for the whole
   segment and squared every cap -- and in one configuration left the
   sweep frame flipped, so OpenCASCADE failed to build the solid at all.

Now a small profile_basis() helper builds every cross section's frame the
same way: profile Y = Axis, profile normal = RefDirection, and -- when
RefDirection is absent -- profile normal = the directrix tangent, so the
section stays perpendicular to the path (buildingSMART IFC4.x-IF #147).

When the two bracketing placements ask for the same orientation the sweep
frame carries it, built against the curve. When they disagree the sweep
frame stays on the shared Axis (continuous with the neighbouring
consistent segments, so nothing flips) and each end's own authored
orientation is folded into its profile points via a change of basis, so
each end cap still lands exactly as authored while the body in between
keeps following the directrix. The all-equal and no-direction-vector
paths are unchanged.

The two mappings now also carry the raw RefDirection through on
cross_section, alongside the existing rotation matrix.

Adds C++ tests (a raked end logs no GEO 42; a directrix that does not run
along +X still lofts a full-size solid) and Python tests (uniform prism
raked at one end and square at the other; a north-south directrix keeps
its width; OffsetLateral/OffsetVertical are scaled by the model length
unit).

* Renames profile_rotations to profile_axis for consistency with profile_ref_directions
2026-09-01 10:35:11 -07:00
2026-07-20 10:46:20 +10:00
2026-08-10 06:15:49 +02:00
2026-05-18 19:24:25 +02:00
2026-08-08 03:44:56 +02:00
2026-02-18 09:09:46 +11:00
2026-05-08 16:20:26 +02:00
2026-05-08 16:20:26 +02:00
2026-05-08 16:20:26 +02:00
2026-08-25 18:55:14 +05:00
2026-08-10 05:19:17 +02:00

IfcOpenShell

IfcOpenShell is an open source (LGPL) software library for working with Industry Foundation Classes (IFC). Complete parsing support is provided for IFC2x3 TC1, IFC4 Add2 TC1, IFC4x1, IFC4x2, and IFC4x3 Add2. Extensive geometric support is implemented for the IFC releases IFC2x3 TC1 and IFC4 Add2 TC1. Extending with support for arbitrary IFC schemas is possible at compile-time when using C++ and at run-time when using Python.

In addition to a C++ and Python API, IfcOpenShell comes with an ecosystem of tools, notably including IfcConvert (an application to convert IFC models to other formats), Bonsai (an add-on to Blender providing a graphical IFC authoring platform), and many other libraries, CLI apps, and more. Support is also provided for auxiliary standards such as BCF and IDS.

For more information, see:

Development is sponsored through your generous donations!

Open Collective Contributors

Contents

Name Description License Service
bcf Library to read and write BCF-XML and query OpenCDE BCF-API modules LGPL-3.0-or-later PyPI Anaconda-Server Badge
bonsai Add-on to Blender providing a graphical native IFC authoring platform GPL-3.0-or-later Official GitHub Unstable Chocolatey
bsdd Library to query the bSDD API LGPL-3.0-or-later PyPI
ifc2ca Utility to convert IFC structural analysis models to Code_Aster LGPL-3.0-or-later
ifc4d Convert to and from IFC and project management software LGPL-3.0-or-later PyPI
ifc5d Report and optimise cost information from IFC LGPL-3.0-or-later PyPI
ifcbimtester Wrapper for Gherkin based unit testing for IFC models LGPL-3.0-or-later
ifcblender Historic Blender IFC import add-on LGPL-3.0-or-later*
ifccityjson Convert CityJSON to IFC LGPL-3.0-or-later PyPI
ifcclash Clash detection library and CLI app LGPL-3.0-or-later PyPI
ifcconvert CLI app to convert IFC to many other formats LGPL-3.0-or-later* Official GitHub
ifccsv Library and CLI app to export and import schedules from IFC LGPL-3.0-or-later PyPI
ifcdiff Compare changes between IFC models LGPL-3.0-or-later PyPI
ifcedit CLI wrapper for ifcopenshell.api IFC model mutation functions LGPL-3.0-or-later PyPI
ifcfm Extract IFC data for FM handover requirements LGPL-3.0-or-later PyPI
ifcmax Historic extension for IFC support in 3DS Max LGPL-3.0-or-later* Official
ifcmcp MCP server for querying and editing IFC building models LGPL-3.0-or-later PyPI
ifcopenshell-python Python library for IFC manipulation LGPL-3.0-or-later* Official GitHub PyPI Anaconda Anaconda Docker AUR AUR Unstable Pyodide WASM Wheels tag
ifcpatch Utility to run pre-packaged scripts to manipulate IFCs LGPL-3.0-or-later PyPI
ifcquery CLI tool for querying and inspecting IFC building models LGPL-3.0-or-later PyPI
ifcsverchok Blender Add-on for visual node programming with IFC GPL-3.0-or-later GitHub
ifctester Library, CLI and webapp for IDS model auditing LGPL-3.0-or-later PyPI

The IfcOpenShell C++ codebase is split into multiple interal libraries:

Name Description License
ifcgeom Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcgeom_schema_agnostic Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcgeomserver Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcjni Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcparse Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcwrap Internal library for IfcOpenShell LGPL-3.0-or-later*
serializers Internal library for IfcOpenShell LGPL-3.0-or-later*
S
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