Correct OBJ texture-coordinate indices (#8457)

The OBJ serializer wrote the normal index into the texture-coordinate slot
of a v/vt/vn face (emitting v/vn/vn), so exported UVs were wrong. Track a
separate texcoord counter and emit the correct vt index.

Per review, the material lookup is left relying on ApplyDefaultMaterials
(default on, and IfcConvert exposes no toggle to disable it) so an unstyled
element is given the default style before triangulation and material_ids
never contain the -1 no-style sentinel, matching how the Collada serializer
already indexes its materials without an ad hoc guard. The earlier
material_id >= 0 guard is therefore removed.

Verified on OCC 7.9.2: a styled box exports its material, an unstyled box
exports the injected DefaultMaterial (valid index, no out-of-bounds) on
both the default and --generate-uvs paths, and the UV path now emits
correct v/vt/vn indices.

Generated with the assistance of an AI coding tool.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/bonsai/bonsai/bim/module/drawing/gizmos.py

@@ -82,7 +82,15 @@ import math
 from collections.abc import Callable, Iterator
 from dataclasses import dataclass
 from enum import Enum
-from typing import Any, ClassVar, Literal, Optional, Protocol, runtime_checkable
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    ClassVar,
+    Literal,
+    Optional,
+    Protocol,
+    runtime_checkable,
+)
 
 import blf
 import bpy
@@ -105,6 +113,9 @@ from mathutils.kdtree import KDTree
 import bonsai.tool as tool
 from bonsai.bim.module.drawing.shaders import ExtrusionGuidesShader
 
+if TYPE_CHECKING:
+    import bmesh
+
 SNAP_POINT_SIZE = 10.0
 SNAP_POINT_COLOR = (1.0, 0.5, 0.0, 1.0)
 SNAP_MAX_RADIUS = 50.0
@@ -2035,7 +2046,9 @@ class TexturedQuadGizmoMixin(StaticTrisGizmoMixin):
 
     def setup(self) -> None:
         super().setup()
-        from bonsai.bim.module.drawing import gizmo_textures
+        from bonsai.bim.module.drawing import (
+            gizmo_textures,  # ty: ignore[unresolved-import]
+        )
 
         self._quad_batch = batch_for_shader(
             gizmo_textures.get_shader(),
@@ -2044,7 +2057,9 @@ class TexturedQuadGizmoMixin(StaticTrisGizmoMixin):
         )
 
     def draw(self, context: bpy.types.Context) -> None:
-        from bonsai.bim.module.drawing import gizmo_textures
+        from bonsai.bim.module.drawing import (
+            gizmo_textures,  # ty: ignore[unresolved-import]
+        )
 
         texture = gizmo_textures.get_icon_texture(self.icon_name)
         if texture is None:

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -981,7 +981,9 @@ class CreateDrawing(bpy.types.Operator):
             # Specifically for PLAN_VIEW and REFLECTED_PLAN_VIEW, any Plan context is also prioritised.
             contexts = self.get_linework_contexts(ifc, target_view)
             self.serialize_contexts_elements(ifc, tree, contexts, "body", drawing_elements, target_view, link_matrix)
-            self.serialize_contexts_elements(ifc, tree, contexts, "annotation", drawing_elements, target_view, link_matrix)
+            self.serialize_contexts_elements(
+                ifc, tree, contexts, "annotation", drawing_elements, target_view, link_matrix
+            )
 
             if tool.Ifc.get() == ifc and self.camera_element not in drawing_elements:
                 with profile("Camera element"):

src/bonsai/bonsai/bim/module/model/__init__.py

@@ -27,6 +27,7 @@ import bonsai.tool as tool
 from . import (
     array,
     covering,
+    decorator,
     door,
     external,
     grid,

src/bonsai/bonsai/bim/module/model/mep.py

@@ -38,6 +38,7 @@ import numpy as np
 from ifcopenshell.util.shape_builder import ShapeBuilder
 from mathutils import Matrix, Vector
 
+import bonsai.core.geometry
 import bonsai.core.root
 import bonsai.tool as tool
 from bonsai.bim.module.drawing import gizmos as gizmo

src/bonsai/bonsai/bim/module/model/railing.py

@@ -138,7 +138,7 @@ def update_bbim_railing_pset(element: ifcopenshell.entity_instance, railing_data
 
 def generate_wall_mounted_handrail_preview(
     obj: bpy.types.Object,
-    props: "BIMRailingProperties",
+    props: "prop.BIMRailingProperties",
     path_data: dict[str, Any],
     si_conversion: float,
 ) -> None:
@@ -860,7 +860,9 @@ class GizmoRailingSchematic(bpy.types.GizmoGroup, gizmo.BaseSchematicGizmoGroup)
         terminal_world = anchor + billboard_rot @ view_rotation @ terminal_local
         self.terminal_gizmo.matrix_basis = gizmo.billboarded_at(terminal_world, billboard_rot, 0.18)
 
-    def update_editing_gizmos(self, context: bpy.types.Context, mw: "Matrix", props: "BIMRailingProperties") -> None:
+    def update_editing_gizmos(
+        self, context: bpy.types.Context, mw: "Matrix", props: "prop.BIMRailingProperties"
+    ) -> None:
         """Hide the pen gizmo while polyline path-edit is active; reposition the cycle icon.
 
         The base class shows the pen gizmo whenever ``is_editing`` is False,

src/bonsai/bonsai/core/drawing.py

@@ -302,23 +302,25 @@ def add_drawing(
         context=drawing.get_body_context(),
         ifc_representation_class=None,
     )
-    
+
     drawings_parent_group = None
     for group in ifc.get().by_type("IfcGroup"):
         if group.Name == "DRAWINGS" and group.ObjectType == "DRAWINGS":
             drawings_parent_group = group
             break
-    
+
     if not drawings_parent_group:
         drawings_parent_group = ifc.run("group.add_group")
-        ifc.run("group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"})
-    
+        ifc.run(
+            "group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"}
+        )
+
     group = ifc.run("group.add_group")
     ifc.run("group.edit_group", group=group, attributes={"Name": drawing_name, "ObjectType": "DRAWING"})
     ifc.run("group.assign_group", group=group, products=[element])
-    
+
     ifc.run("group.assign_group", group=drawings_parent_group, products=[group])
-    
+
     collector.assign(camera)
     pset = ifc.run("pset.add_pset", product=element, name="EPset_Drawing")
     if drawing.get_unit_system() == "METRIC":
@@ -355,7 +357,7 @@ def add_drawing(
         if document.Name == "DRAWINGS" and document.Scope == "DRAWINGS":
             drawings_parent_document = document
             break
-    
+
     if not drawings_parent_document:
         drawings_parent_document = ifc.run("document.add_information")
         if ifc.get_schema() == "IFC2X3":
@@ -363,7 +365,7 @@ def add_drawing(
         else:
             attributes = {"Identification": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
         ifc.run("document.edit_information", information=drawings_parent_document, attributes=attributes)
-    
+
     information = ifc.run("document.add_information", parent=drawings_parent_document)
     uri = drawing.get_default_drawing_path(drawing_name)
     reference = ifc.run("document.add_reference", information=information)
@@ -392,17 +394,19 @@ def duplicate_drawing(
     drawing_tool.set_name(new_drawing, drawing_name)
     group = drawing_tool.get_drawing_group(new_drawing)
     ifc.run("group.unassign_group", group=group, products=[new_drawing])
-    
+
     drawings_parent_group = None
     for parent_group in ifc.get().by_type("IfcGroup"):
         if parent_group.Name == "DRAWINGS" and parent_group.ObjectType == "DRAWINGS":
             drawings_parent_group = parent_group
             break
-    
+
     if not drawings_parent_group:
         drawings_parent_group = ifc.run("group.add_group")
-        ifc.run("group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"})
-    
+        ifc.run(
+            "group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"}
+        )
+
     new_group = ifc.run("group.add_group")
     ifc.run("group.edit_group", group=new_group, attributes={"Name": drawing_name, "ObjectType": "DRAWING"})
     ifc.run("group.assign_group", group=new_group, products=[new_drawing])
@@ -427,7 +431,7 @@ def duplicate_drawing(
         if document.Name == "DRAWINGS" and document.Scope == "DRAWINGS":
             drawings_parent_document = document
             break
-    
+
     if not drawings_parent_document:
         drawings_parent_document = ifc.run("document.add_information")
         if ifc.get_schema() == "IFC2X3":

src/bonsai/bonsai/core/product.py

@@ -50,14 +50,15 @@ def copy_z_rotation_to_selected(
     flip: bool = False,
 ) -> int:
     """Apply ``active``'s Z-Euler rotation to each target."""
-    source_z = surveyor.get_z_rotation(active)
+    source_z = surveyor.get_z_rotation(active)  # ty: ignore[missing-argument]
     if flip:
         source_z += math.pi
     rotated = 0
     for obj in targets:
-        if abs(_z_rotation_diff(surveyor.get_z_rotation(obj), source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
+        target_z = surveyor.get_z_rotation(obj)  # ty: ignore[missing-argument]
+        if abs(_z_rotation_diff(target_z, source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
             continue
-        surveyor.set_z_rotation(obj, source_z)
+        surveyor.set_z_rotation(obj, source_z)  # ty: ignore[missing-argument]
         rotated += 1
         if ifc.get_entity(obj) is not None:
             bonsai.core.geometry.edit_object_placement(ifc, geometry, surveyor, obj=obj)

src/bonsai/bonsai/core/tool.py

@@ -804,7 +804,7 @@ class Profile:
 
 @interface
 class Parametric:
-    def get_geom_generation(cls) -> int: pass
+    def get_geom_generation(cls): pass
     def refresh_post_commit(cls, operator) -> None: pass
 
 

src/bonsai/bonsai/tool/model.py

@@ -59,6 +59,7 @@ from ifcopenshell.util.shape_builder import ShapeBuilder, np_to_3d
 from mathutils import Matrix, Vector
 
 import bonsai.core.geometry
+import bonsai.core.model
 import bonsai.core.tool
 import bonsai.tool as tool
 from bonsai.bim import import_ifc

src/bonsai/test/bim/module/model/test_array_batch_recut.py

@@ -35,6 +35,7 @@ from unittest.mock import Mock, patch
 
 import bpy
 import ifcopenshell
+import ifcopenshell.api.pset
 import pytest
 
 import bonsai.tool as tool

src/bonsai/test/bim/module/model/test_array_duplicate_batched.py

@@ -37,6 +37,8 @@ from unittest.mock import patch
 
 import bpy
 import ifcopenshell
+import ifcopenshell.api.pset
+import ifcopenshell.util.element
 import pytest
 
 import bonsai.tool as tool

src/bonsai/test/bim/module/model/test_mep_distribution_fit_smoke.py

@@ -146,7 +146,9 @@ def test_fit_flow_segments_with_single_segment_dispatches_obstruction():
         mep.tool.Model, "get_flow_segment_profile", return_value=segment_profile
     ), patch.object(mep.MEPAddObstruction, "_execute", return_value=None) as obstruction, patch.object(
         mep.MEPAddBend, "_execute", return_value=None
-    ) as bend, patch.object(mep.MEPAddTransition, "_execute", return_value=None) as transition:
+    ) as bend, patch.object(
+        mep.MEPAddTransition, "_execute", return_value=None
+    ) as transition:
         mep.FitFlowSegments._execute(op, context=context)
 
     assert obstruction.call_count == 1
@@ -178,7 +180,9 @@ def test_fit_flow_segments_refuses_mixed_pipe_and_duct():
         mep.tool.Model, "get_flow_segment_profile", return_value=profile
     ), patch.object(mep.MEPAddObstruction, "_execute", return_value=None) as obstruction, patch.object(
         mep.MEPAddBend, "_execute", return_value=None
-    ) as bend, patch.object(mep.MEPAddTransition, "_execute", return_value=None) as transition:
+    ) as bend, patch.object(
+        mep.MEPAddTransition, "_execute", return_value=None
+    ) as transition:
         mep.FitFlowSegments._execute(op, context=context)
 
     obstruction.assert_not_called()

src/bonsai/test/bim/module/model/test_mep_segment_edition.py

@@ -173,8 +173,9 @@ def test_gizmo_group_class_wiring(gizmo_cls_name, bl_idname, is_element_predicat
     predicate = getattr(tool.Parametric, is_element_predicate)
     fake_element = Mock()
     fake_element.is_a.return_value = True
-    with patch.object(tool.Parametric, is_element_predicate, side_effect=predicate) as p, patch.object(
-        tool.System, "has_parametric_body", return_value=True
+    with (
+        patch.object(tool.Parametric, is_element_predicate, side_effect=predicate) as p,
+        patch.object(tool.System, "has_parametric_body", return_value=True),
     ):
         cls.is_element_type(fake_element)
     assert p.called, f"{gizmo_cls_name}.is_element_type did not delegate to Parametric.{is_element_predicate}"

src/bonsai/test/bim/test_preview_cancel_ops_forward_compat.py

@@ -139,6 +139,5 @@ def test_every_cancel_ops_entry_has_a_real_preview_propertygroup() -> None:
     orphaned = [attr for attr, _op in preview_base.PREVIEW_CANCEL_OPS if attr not in declared_attrs]
     assert not orphaned, (
         "PREVIEW_CANCEL_OPS contains entries whose PointerProperty child no longer "
-        f"exists on {UMBRELLA_CLASS}. Drop the stale tuple(s):\n  "
-        + "\n  ".join(orphaned)
+        f"exists on {UMBRELLA_CLASS}. Drop the stale tuple(s):\n  " + "\n  ".join(orphaned)
     )

src/bonsai/test/modal/test_modal.py

@@ -24,6 +24,7 @@ import time
 
 import bpy
 import ifcopenshell
+import ifcopenshell.util.element
 import pytest
 
 from bonsai import tool as tool

src/bonsai/test/tool/test_model.py

@@ -23,6 +23,7 @@ import bpy
 import ifcopenshell
 import ifcopenshell.api.geometry
 import ifcopenshell.api.material
+import ifcopenshell.api.pset
 import ifcopenshell.api.root
 import ifcopenshell.api.style
 import ifcopenshell.api.type

src/ifc5d/ifc5d/csv2ifc.py

@@ -57,7 +57,8 @@ class CsvHeader(TypedDict):
 
     # Formula
     Formula: NotRequired[str]
-    #QuantityClass: NotRequired[str]
+    # QuantityClass: NotRequired[str]
+
 
 # Currently we assume that if column is not part of the main header,
 # then it is a cost value category. So here we list any additional column
@@ -97,7 +98,8 @@ class CostItem(TypedDict):
     Query: Union[str, None]
 
     Formula: Union[str, None]
-    #QuantityClass: Union[str, None]
+    # QuantityClass: Union[str, None]
+
 
 class Csv2Ifc:
     # Inputs.
@@ -420,7 +422,7 @@ class Csv2Ifc:
                     products=results,
                     formula=cost_item["Formula"],
                     ifc_class=ifc_quantity_class,
-                    )
+                )
 
         self.create_cost_items(cost_item["children"], cost_item["ifc"])
 

src/ifcopenshell-python/ifcopenshell/__init__.py

@@ -231,7 +231,7 @@ def open(
         kwargs = {"mmap": mmap}
         if logger is not None:
             kwargs["logger"] = logger
-        f = ifcopenshell_wrapper.open(str(path.absolute()), **kwargs)  # ty: ignore[unknown-argument]
+        f = ifcopenshell_wrapper.open(str(path.absolute()), **kwargs)
     else:
         f = ifcopenshell_wrapper.open(str(path.absolute()), False, *((logger,) if logger is not None else ()))
     return file(f)

src/ifcopenshell-python/ifcopenshell/api/alignment/__init__.py

@@ -49,6 +49,7 @@ Future versions of this API may support:
 
 from ._get_segment_start_point_label import register_referent_name_callback
 from .add_stationing_referent import add_stationing_referent
+from .add_positioning_referent import add_positioning_referent
 from .add_vertical_layout import add_vertical_layout
 from .add_zero_length_segment import add_zero_length_segment
 from .create import create
@@ -94,6 +95,7 @@ from .util import *
 
 __all__ = [
     "add_stationing_referent",
+    "add_positioning_referent",
     "add_vertical_layout",
     "add_zero_length_segment",
     "create",

src/ifcopenshell-python/ifcopenshell/api/alignment/_add_segment_to_curve.py

@@ -22,8 +22,6 @@ import numpy as np
 import ifcopenshell
 import ifcopenshell.api.alignment
 import ifcopenshell.geom
-import ifcopenshell.ifcopenshell_wrapper as ifcopenshell_wrapper
-import ifcopenshell.util.unit
 from ifcopenshell import entity_instance
 from ifcopenshell.api.alignment._get_segment_endpoint import _get_segment_endpoint
 from ifcopenshell.api.alignment._update_zero_length_segment_placement import _update_zero_length_segment_placement

src/ifcopenshell-python/ifcopenshell/api/alignment/_add_segment_to_layout.py

@@ -22,28 +22,11 @@ import numpy as np
 
 import ifcopenshell
 import ifcopenshell.api.alignment
-from ifcopenshell.api.alignment import _map_alignment_cant_segment
 from ifcopenshell.api.alignment._update_zero_length_segment_placement import _update_zero_length_segment_placement
 import ifcopenshell.api.nest
-import ifcopenshell.api.pset
-import ifcopenshell.geom
-import ifcopenshell.util.alignment
-import ifcopenshell.util.unit
-from ifcopenshell import entity_instance, ifcopenshell_wrapper
+from ifcopenshell import entity_instance
 from ifcopenshell.api.alignment._add_segment_to_curve import _add_segment_to_curve
 from ifcopenshell.api.alignment._get_segment_endpoint import _get_segment_endpoint
-from ifcopenshell.api.alignment._get_segment_start_point_label import (
-    _get_segment_start_point_label,
-)
-from ifcopenshell.api.alignment._map_alignment_cant_segment import (
-    _map_alignment_cant_segment,
-)
-from ifcopenshell.api.alignment._map_alignment_horizontal_segment import (
-    _map_alignment_horizontal_segment,
-)
-from ifcopenshell.api.alignment._map_alignment_vertical_segment import (
-    _map_alignment_vertical_segment,
-)
 
 
 def _add_segment_to_layout(

src/ifcopenshell-python/ifcopenshell/api/alignment/_add_zero_length_segment.py

@@ -18,11 +18,7 @@
 
 import ifcopenshell
 import ifcopenshell.api.alignment
-import ifcopenshell.util.alignment
 from ifcopenshell import entity_instance
-from ifcopenshell.api.alignment._get_segment_start_point_label import (
-    _get_segment_start_point_label,
-)
 
 
 def _add_zero_length_segment(file: ifcopenshell.file, layout: entity_instance) -> None:

src/ifcopenshell-python/ifcopenshell/api/alignment/_get_segment_endpoint.py

@@ -18,6 +18,7 @@
 
 
 import ifcopenshell.api.alignment
+import ifcopenshell.geom
 from ifcopenshell import entity_instance, ifcopenshell_wrapper
 from ifcopenshell.api.alignment._map_alignment_segment import _map_alignment_segment
 from typing import Union

src/ifcopenshell-python/ifcopenshell/api/alignment/add_positioning_referent.py

@@ -0,0 +1,113 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2025 Thomas Krijnen <thomas@aecgeeks.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.alignment
+from ifcopenshell.api.alignment.update_fallback_position import update_fallback_position
+import ifcopenshell.api.pset
+import ifcopenshell.guid
+from ifcopenshell import entity_instance
+
+
+def add_positioning_referent(
+    file: ifcopenshell.file,
+    name: str,
+    alignment: entity_instance,
+    distance_along: float,
+    station: float,
+    positioned_product: entity_instance,
+) -> entity_instance:
+    """
+    Semantically defines the position of a product along an alignment by adding an IfcReferent to the alignment that defines the stationing system.
+
+    :param alignment: the alignment to receive the referent
+    :param distance_along: distance along the alignment basis curve
+    :param station: station value
+    :param name: name to assign to IfcReferent.Name, typically a stringized version of the station value
+    :param positioned_product: the product whose position is informed by the referent
+    :return: referent
+
+    Example:
+
+    .. code:: python
+
+        alignment = model.by_type("IfcAlignment")[0]
+        pier = model.by_type("IfcBridgePart")[0]
+        ifcopenshell.api.alignment.add_positioning_referent(model,name="Pier 1 Sta 1+00",alignment=alignment,distance_along=0.0,station=100.0,positioned_product=pier)
+    """
+
+    curve = ifcopenshell.api.alignment.get_curve(alignment)
+
+    object_placement = None
+    representation = None
+    if curve and curve.is_a("IfcCompositeCurve") and 0 < len(curve.Segments):
+        object_placement = file.createIfcLinearPlacement(
+            RelativePlacement=file.createIfcAxis2PlacementLinear(
+                Location=file.createIfcPointByDistanceExpression(
+                    DistanceAlong=file.createIfcLengthMeasure(distance_along),
+                    OffsetLateral=None,
+                    OffsetVertical=None,
+                    OffsetLongitudinal=None,
+                    BasisCurve=curve,
+                )
+            ),
+        )
+
+        update_fallback_position(file, object_placement)
+    else:
+        object_placement = file.createIfcLocalPlacement(
+            PlacementRelTo=None,
+            RelativePlacement=file.createIfcAxis2Placement2D(
+                Location=file.createIfcCartesianPoint(alignment.ObjectPlacement.RelativePlacement.Location.Coordinates)
+            ),
+        )
+
+    # this commented out code is what you would do to add a geometric representation of the referent
+    # the example is a circle. a better way would be to pass a representation into the function
+    #    representation = file.create_entity(
+    #        name="IfcCircle",
+    #        position=file.createIfcAxis2Placement2D(Location=file.createIfcCartesianPoint(Coordinates=(0.0, 0.0)),
+    #        radius=1.0)
+    #    )
+
+    # create referent for the station
+    referent = file.createIfcReferent(
+        GlobalId=ifcopenshell.guid.new(),
+        OwnerHistory=None,
+        Name=name,
+        Description=None,
+        ObjectType=None,
+        ObjectPlacement=object_placement,
+        Representation=representation,
+        PredefinedType="POSITION",
+    )
+    pset_stationing = ifcopenshell.api.pset.add_pset(file, product=referent, name="Pset_Stationing")
+    ifcopenshell.api.pset.edit_pset(file, pset=pset_stationing, properties={"Station": station})
+
+    if len(referent.Positions) == 0:
+        rel_positions = file.createIfcRelPositions(
+            GlobalId=ifcopenshell.guid.new(),
+            RelatingPositioningElement=referent,
+            RelatedProducts=[
+                positioned_product,
+            ],
+        )
+    else:
+        referent.Positions[0].RelatedProducts += (positioned_product,)
+
+    return referent

src/ifcopenshell-python/ifcopenshell/api/alignment/add_stationing_referent.py

@@ -16,35 +16,35 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
-import numpy as np
+from typing import Optional
 
 import ifcopenshell
 import ifcopenshell.api.alignment
 from ifcopenshell.api.alignment.update_fallback_position import update_fallback_position
 import ifcopenshell.api.pset
-import ifcopenshell.geom
 import ifcopenshell.guid
 import ifcopenshell.util.element
-import ifcopenshell.util.unit
-from ifcopenshell import entity_instance, ifcopenshell_wrapper
+from ifcopenshell import entity_instance
 
 
 def add_stationing_referent(
     file: ifcopenshell.file,
+    name: str,
     alignment: entity_instance,
     distance_along: float,
     station: float,
-    name: str,
-    positioned_product: entity_instance,
+    incoming_station: Optional[float] = None,
+    on_basis_curve: Optional[bool] = None,
 ) -> entity_instance:
     """
-    Adds an IfcReferent to the alignment with the Pset_Stationing property set.
+    Adds an IfcReferent to the alignment that defines the stationing system.
 
+    :param name: name to assign to IfcReferent.Name, typically a stringized version of the station value
     :param alignment: the alignment to receive the referent
     :param distance_along: distance along the alignment basis curve
     :param station: station value
-    :param name: name to assign to IfcReferent.Name, typically a stringized version of the station value
-    :param positioned_product: the product whose position is informed by the referent
+    :param incoming_station: station value of the incoming segment, only set to specify a station equation
+    :param on_basis_curve: whether the referent is positioned on the basis curve or the alignment curve, if None the function will default to the basis curve
     :return: referent
 
     Example:
@@ -52,14 +52,21 @@ def add_stationing_referent(
     .. code:: python
 
         alignment = model.by_type("IfcAlignment")[0]
-        ifcopenshell.api.alignment.add_stationing_referent(model,alignment=alignment,distance_along=0.0,station=100.0)
+        ifcopenshell.api.alignment.add_stationing_referent(model,name="1+00.0",alignment=alignment,distance_along=0.0,station=100.0)
     """
 
-    basis_curve = ifcopenshell.api.alignment.get_basis_curve(alignment)
+    if on_basis_curve is None:
+        on_basis_curve = True
+
+    curve = (
+        ifcopenshell.api.alignment.get_basis_curve(alignment)
+        if on_basis_curve
+        else ifcopenshell.api.alignment.get_curve(alignment)
+    )
 
     object_placement = None
     representation = None
-    if basis_curve and basis_curve.is_a("IfcCompositeCurve") and 0 < len(basis_curve.Segments):
+    if curve and curve.is_a("IfcCompositeCurve") and 0 < len(curve.Segments):
         object_placement = file.createIfcLinearPlacement(
             RelativePlacement=file.createIfcAxis2PlacementLinear(
                 Location=file.createIfcPointByDistanceExpression(
@@ -67,7 +74,7 @@ def add_stationing_referent(
                     OffsetLateral=None,
                     OffsetVertical=None,
                     OffsetLongitudinal=None,
-                    BasisCurve=basis_curve,
+                    BasisCurve=curve,
                 )
             ),
         )
@@ -100,8 +107,12 @@ def add_stationing_referent(
         Representation=representation,
         PredefinedType="STATION",
     )
+    properties = {"Station": station}
+    if incoming_station is not None:
+        properties["IncomingStation"] = incoming_station
+
     pset_stationing = ifcopenshell.api.pset.add_pset(file, product=referent, name="Pset_Stationing")
-    ifcopenshell.api.pset.edit_pset(file, pset=pset_stationing, properties={"Station": station})
+    ifcopenshell.api.pset.edit_pset(file, pset=pset_stationing, properties=properties)
 
     nest = ifcopenshell.api.alignment.get_referent_nest(file, alignment)
     if nest is None:
@@ -115,15 +126,4 @@ def add_stationing_referent(
         nest.RelatedObjects, key=lambda x: ifcopenshell.util.element.get_pset(x, name="Pset_Stationing", prop="Station")
     )
 
-    if len(referent.Positions) == 0:
-        rel_positions = file.createIfcRelPositions(
-            GlobalId=ifcopenshell.guid.new(),
-            RelatingPositioningElement=referent,
-            RelatedProducts=[
-                positioned_product,
-            ],
-        )
-    else:
-        referent.Positions[0].RelatedProducts += (positioned_product,)
-
     return referent

src/ifcopenshell-python/ifcopenshell/api/alignment/add_vertical_layout.py

@@ -51,18 +51,6 @@ def _move_vertical_layout_to_child_alignment(
     # aggregate the child alignment to the parent alignment
     ifcopenshell.api.aggregate.assign_object(file, products=[child_alignment], relating_object=parent_alignment)
 
-    # move all referents positioning segments of the vertical layout to the referent nest of the child alignment
-    child_referent_nest = ifcopenshell.api.alignment.get_referent_nest(file, child_alignment)
-    parent_referent_nest = ifcopenshell.api.alignment.get_referent_nest(file, parent_alignment)
-    for referent in parent_referent_nest.RelatedObjects:
-        for product in referent.Positions[0].RelatedProducts:
-            if product.is_a("IfcAlignmentSegment") and product.Nests[0].RelatingObject == vertical_layout:
-                # ifcopenshell.api.nest.change_nest(file,referent,child_alignment) - this doesn't work because referent is assigned to child_alignment.IsNestedBy[0].RelatedObjects
-                # and it needs to be assigned to child_alignment.IsNestedBy[1].RelatedObjects
-                # move the referent manually - unassign it and add it to the child alignment's referent nest
-                ifcopenshell.api.nest.unassign_object(file, [referent])
-                child_referent_nest.RelatedObjects += (referent,)
-
     # if the parent alignment has a representation, move the Axis/Curve3D represention to the child alignment
     base_curve = ifcopenshell.api.alignment.get_basis_curve(parent_alignment)
     if base_curve:

src/ifcopenshell-python/ifcopenshell/api/alignment/add_zero_length_segment.py

@@ -23,18 +23,8 @@ import ifcopenshell.api.alignment
 from ifcopenshell.api.alignment._get_segment_endpoint import _get_segment_endpoint
 from ifcopenshell.api.alignment._update_zero_length_segment_placement import _update_zero_length_segment_placement
 import ifcopenshell.api.nest
-import ifcopenshell.ifcopenshell_wrapper as wrapper
 import ifcopenshell.util.unit
 from ifcopenshell import entity_instance
-from ifcopenshell.api.alignment._get_segment_start_point_label import (
-    _get_segment_start_point_label,
-)
-from ifcopenshell.api.alignment._map_alignment_horizontal_segment import (
-    _map_alignment_horizontal_segment,
-)
-from ifcopenshell.api.alignment._map_alignment_vertical_segment import (
-    _map_alignment_vertical_segment,
-)
 from ifcopenshell.api.alignment._update_curve_segment_transition_code import (
     _update_curve_segment_transition_code,
 )

src/ifcopenshell-python/ifcopenshell/api/alignment/create.py

@@ -87,9 +87,7 @@ def create(
         _create_geometric_representation(file, alignment)
 
     referent_name = ifcopenshell.util.alignment.station_as_string(file, start_station)
-    referent = ifcopenshell.api.alignment.add_stationing_referent(
-        file, alignment, 0.0, start_station, referent_name, alignment
-    )
+    referent = ifcopenshell.api.alignment.add_stationing_referent(file, referent_name, alignment, 0.0, start_station)
 
     for layout in alignment_layouts:
         _add_zero_length_segment(file, layout)

src/ifcopenshell-python/ifcopenshell/api/alignment/create_as_polyline.py

@@ -141,7 +141,7 @@ def create_as_polyline(
 
     # define stationing
     name = ifcopenshell.util.alignment.station_as_string(file, start_station)
-    referent = ifcopenshell.api.alignment.add_stationing_referent(file, alignment, 0.0, start_station, name, alignment)
+    referent = ifcopenshell.api.alignment.add_stationing_referent(file, name, alignment, 0.0, start_station)
 
     # IFC 4.1.4.1.1 Alignment Aggregation To Project
     project = file.by_type("IfcProject")[0]

src/ifcopenshell-python/ifcopenshell/api/alignment/create_layout_segment.py

@@ -21,9 +21,7 @@ from typing import Union
 import numpy as np
 
 import ifcopenshell
-import ifcopenshell.api.alignment
-import ifcopenshell.geom
-from ifcopenshell import entity_instance, ifcopenshell_wrapper
+from ifcopenshell import entity_instance
 from ifcopenshell.api.alignment._add_segment_to_layout import _add_segment_to_layout
 
 

src/ifcopenshell-python/ifcopenshell/api/alignment/distance_along_from_station.py

@@ -16,23 +16,47 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
+from typing import Optional
+
 import ifcopenshell
 import ifcopenshell.api.alignment
+import ifcopenshell.util.element
 from ifcopenshell import entity_instance
 
 
-def distance_along_from_station(file: ifcopenshell.file, alignment: entity_instance, station: float) -> float:
+def _distance_along_of_referent(referent: entity_instance) -> float:
+    placement = referent.ObjectPlacement
+    if placement.is_a("IfcLinearPlacement"):
+        return placement.RelativePlacement.Location.DistanceAlong.wrappedValue
+    # IfcLocalPlacement fallback (e.g. semantic-only alignment, or the placement could not yet
+    # be expressed relative to a basis curve) carries no DistanceAlong; it is only ever used for
+    # the starting referent, at distance 0.0.
+    return 0.0
+
+
+def distance_along_from_station(file: ifcopenshell.file, alignment: entity_instance, station: float) -> Optional[float]:
     """
     Given a station, returns the distance along the horizontal alignment.
 
     If the alignment does not have stationing defined with an IfcReferent, the start of the alignment is assumed
     to be at station 0.0. That is, the station is the distance along.
 
-    .. note:: The current implementation does not account for station equations and assumes stationing is increasing along the alignment.
+    Station equations (where Pset_Stationing.IncomingStation is set on a referent) are taken into account.
+    For each STATION referent nested to the alignment, DistanceAlong (D) and the outgoing station (S, i.e.
+    Pset_Stationing.Station) are read off, sorted by DistanceAlong. The requested station is located within
+    the segment defined by the last referent whose outgoing station is less than or equal to it, and the
+    distance along is computed as D + (station - S) for that referent.
+
+    If the station falls within a gap introduced by a forward (gap) station equation - that is, it was skipped
+    over by the equation - there is no distance along that corresponds to it, and None is returned.
+
+    Note that an overlap (backward) station equation causes a range of stations to correspond to two distinct
+    distances along the alignment, one on either side of the equation. This implementation returns the distance
+    along in the segment following the equation (i.e. the outgoing side).
 
     :param alignment: the alignment
     :param station: station value
-    :return: distance along the horizontal alignment
+    :return: distance along the horizontal alignment, or None if the station falls inside a station equation gap
 
     Example:
 
@@ -43,6 +67,36 @@ def distance_along_from_station(file: ifcopenshell.file, alignment: entity_insta
         print(dist_along) # 100.00
     """
 
-    start_station = ifcopenshell.api.alignment.get_alignment_start_station(file, alignment)
-    dist_along = station - start_station
-    return dist_along
+    referent_nest = ifcopenshell.api.alignment.get_referent_nest(file, alignment)
+    if referent_nest is None:
+        start_station = ifcopenshell.api.alignment.get_alignment_start_station(file, alignment)
+        return station - start_station
+
+    stations = [
+        (
+            _distance_along_of_referent(referent),
+            ifcopenshell.util.element.get_pset(referent, name="Pset_Stationing", prop="Station"),
+        )
+        for referent in referent_nest.RelatedObjects
+    ]
+    stations.sort(key=lambda entry: entry[0])
+
+    index = None
+    for i, (distance_along, outgoing_station) in enumerate(stations):
+        if outgoing_station <= station:
+            index = i
+
+    if index is None:
+        # station precedes the alignment's starting station; extrapolate from the first referent
+        distance_along, outgoing_station = stations[0]
+        return distance_along + (station - outgoing_station)
+
+    distance_along, outgoing_station = stations[index]
+
+    if index + 1 < len(stations):
+        next_distance_along, _ = stations[index + 1]
+        if station - outgoing_station > next_distance_along - distance_along:
+            # the station was skipped over by a forward (gap) station equation
+            return None
+
+    return distance_along + (station - outgoing_station)

src/ifcopenshell-python/ifcopenshell/api/alignment/get_curve_segment.py

@@ -16,7 +16,6 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
-from collections.abc import Sequence
 
 from ifcopenshell import entity_instance
 

src/ifcopenshell-python/ifcopenshell/api/alignment/update_end_point.py

@@ -19,6 +19,7 @@
 import numpy as np
 
 import ifcopenshell
+import ifcopenshell.api.alignment
 import ifcopenshell.util.placement
 from ifcopenshell import entity_instance
 

src/ifcopenshell-python/ifcopenshell/api/cost/assign_cost_item_quantity.py

@@ -117,7 +117,7 @@ def assign_cost_item_quantity(
         "products": products or [],
         "prop_name": prop_name,
         "formula": formula,
-        "ifc_class" : ifc_class
+        "ifc_class": ifc_class,
     }
     return usecase.execute()
 
@@ -134,7 +134,7 @@ class Usecase:
                 continue
             self.assign_cost_control(related_object=product, cost_item=self.settings["cost_item"])
             if self.settings["formula"]:
-                tree = ast.parse(self.settings["formula"], mode = "eval")
+                tree = ast.parse(self.settings["formula"], mode="eval")
                 collector = VariableExtractor()
                 collector.visit(tree)
                 variables = collector.variables
@@ -144,10 +144,10 @@ class Usecase:
                     value = getter(product, variable)
 
                 if value is None:
-                        print(
-                            f"WARNING: Variable '{variable}' in product '{product.Name}' "
-                            f"is missing (None). Check Pset/Qset or property name."
-                        )
+                    print(
+                        f"WARNING: Variable '{variable}' in product '{product.Name}' "
+                        f"is missing (None). Check Pset/Qset or property name."
+                    )
                 elif value == 0:
                     print(
                         f"WARNING: Variable '{variable}' in product '{product.Name}' "
@@ -159,7 +159,9 @@ class Usecase:
 
                 new_quantity = None
                 for quantity in self.quantities:
-                    if quantity.Formula == self.settings["formula"] and len(self.settings["products"]) == 1: #Todo improve it
+                    if (
+                        quantity.Formula == self.settings["formula"] and len(self.settings["products"]) == 1
+                    ):  # Todo improve it
                         new_quantity = quantity
                         self.settings["ifc_class"] = quantity.is_a()
                         continue
@@ -184,23 +186,23 @@ class Usecase:
             self.update_cost_item_count()
 
     def get_value_from_pset(
-            self,
-            product:ifcopenshell.entity_instance,
-            v: str,
+        self,
+        product: ifcopenshell.entity_instance,
+        v: str,
     ) -> float:
         pset_name = v.split(".")[0]
         pset = ifcopenshell.util.element.get_pset(product, pset_name)
         pset_property_name = v.split(".")[1]
-        return (pset or {}).get(pset_property_name,None)
+        return (pset or {}).get(pset_property_name, None)
 
     def get_value_from_qset(
-            self,
-            product:ifcopenshell.entity_instance,
-            v: str,
+        self,
+        product: ifcopenshell.entity_instance,
+        v: str,
     ) -> float:
-        qtos = ifcopenshell.util.element.get_psets(product, qtos_only = True)
+        qtos = ifcopenshell.util.element.get_psets(product, qtos_only=True)
         quantities = next(iter(qtos.values()), {})
-        return (quantities or {}).get(v,None)
+        return (quantities or {}).get(v, None)
 
     def assign_cost_control(
         self, related_object: ifcopenshell.entity_instance, cost_item: ifcopenshell.entity_instance
@@ -243,6 +245,7 @@ class Usecase:
                             count += 1
                 quantity[3] = count
 
+
 OPERATORS = {
     ast.Add: operator.add,
     ast.Sub: operator.sub,
@@ -252,18 +255,20 @@ OPERATORS = {
     ast.USub: operator.neg,
 }
 
+
 def build_full_name(node):
-    #used for variables with dots
+    # used for variables with dots
     parts = []
     while isinstance(node, ast.Attribute):
-            parts.append(node.attr)
-            node = node.value
+        parts.append(node.attr)
+        node = node.value
 
     if isinstance(node, ast.Name):
         parts.append(node.id)
 
     return ".".join(reversed(parts))
 
+
 class VariableExtractor(ast.NodeVisitor):
     def __init__(self):
         self.variables = set()
@@ -274,6 +279,7 @@ class VariableExtractor(ast.NodeVisitor):
     def visit_Attribute(self, node):
         self.variables.add(build_full_name(node))
 
+
 class FormulaEvaluator(ast.NodeVisitor):
     def __init__(self, values):
         self.values = values
@@ -281,7 +287,7 @@ class FormulaEvaluator(ast.NodeVisitor):
     def visit_BinOp(self, node):
         left = self.visit(node.left)
         right = self.visit(node.right)
-        return OPERATORS[type(node.op)](left, right)
+        return OPERATORS[type(node.op)](left, right)  # ty: ignore[too-many-positional-arguments]
 
     def visit_Name(self, node):
         return self.values[node.id]

src/ifcopenshell-python/ifcopenshell/express/bootstrap.py

@@ -221,8 +221,7 @@ for id in to_emit:
     statements.append("%s << %s" % (id, stmt))
 
 if __name__ == "__main__":
-    print(
-        r"""
+    print(r"""
 # This file is generated by IfcOpenShell ifcexpressparser bootstrap.py
 
 from __future__ import annotations
@@ -261,6 +260,4 @@ if __name__ == "__main__":
         mdl = importlib.import_module(output)
         mdl.Generator(m).emit()
     sys.stdout.write(m.schema.name)
-"""
-        % ("\n        ".join(statements))
-    )
+""" % ("\n        ".join(statements)))

src/ifcopenshell-python/ifcopenshell/express/rule_compiler.py

@@ -695,6 +695,7 @@ codegen_rule("MOD", lambda context: "%")
 codegen_rule("TRUE", lambda context: "True")
 codegen_rule("FALSE", lambda context: "False")
 
+
 def _dotted_name(node: ast.AST):
     """Return dotted name for Name/Attribute chains, else None."""
     if isinstance(node, ast.Name):
@@ -704,6 +705,7 @@ def _dotted_name(node: ast.AST):
         return f"{base}.{node.attr}" if base else node.attr
     return None
 
+
 class AttributeGetattrTransformer(ast.NodeTransformer):
     def visit_Attribute(self, node):
         parents = []
@@ -720,7 +722,7 @@ class AttributeGetattrTransformer(ast.NodeTransformer):
         if isinstance(node.ctx, ast.Store):
             return node
 
-        if _dotted_name(node) in ('ifcopenshell.create_entity', 'str.lower'):
+        if _dotted_name(node) in ("ifcopenshell.create_entity", "str.lower"):
             return node
 
         if node.attr.startswith("__"):

src/ifcopenshell-python/ifcopenshell/express/schema_class.py

@@ -363,24 +363,18 @@ class EarlyBoundCodeWriter:
             )
         )
 
-        self.statements[self.statements.index("{factory_placeholder}")] = (
-            """
+        self.statements[self.statements.index("{factory_placeholder}")] = """
 class %(schema_name)s_instance_factory : public IfcParse::instance_factory {
     virtual IfcUtil::IfcBaseClass* operator()(const IfcParse::declaration* decl, IfcEntityInstanceData&& data) const {
         %(instance_mapping)s
     }
 };
-"""
-            % locals()
-        )
+""" % locals()
 
         ""
-        self.statements[self.statements.index("{string_pool_placeholder}")] = (
-            """
+        self.statements[self.statements.index("{string_pool_placeholder}")] = """
 const std::string strings[] = {%s};
-"""
-            % ",".join(map(lambda s: '"%s"s' % s, self.strings))
-        )
+""" % ",".join(map(lambda s: '"%s"s' % s, self.strings))
 
     def __str__(self):
         return "\n".join(self.statements)

src/ifcopenshell-python/ifcopenshell/geom/app.py

@@ -145,8 +145,7 @@ class configuration:
             config.set(
                 "snippets",
                 "print all wall ids",
-                self.config_encode(
-                    """
+                self.config_encode("""
 ###########################################################################
 # A simple script that iterates over all walls in the current model       #
 # and prints their Globally unique IDs (GUIDS) to the console window      #
@@ -154,15 +153,13 @@ class configuration:
 
 for wall in model.by_type("IfcWall"):
     print ("wall with global id: "+str(wall.GlobalId))
-""".lstrip()
-                ),
+""".lstrip()),
             )
 
             config.set(
                 "snippets",
                 "print properties of current selection",
-                self.config_encode(
-                    """
+                self.config_encode("""
 ###########################################################################
 # A simple script that iterates over all IfcPropertySets of the currently #
 # selected object and prints them to the console                          #
@@ -180,8 +177,7 @@ if selection:
              for prop in relDefinesByProperties.RelatingPropertyDefinition.HasProperties:
                  print ("{:<20} :{}".format(prop.Name,prop.NominalValue.wrappedValue))
          print ("\\n")
-""".lstrip()
-                ),
+""".lstrip()),
             )
             with open(conf_file, "w") as configfile:
                 config.write(configfile)

src/ifcopenshell-python/ifcopenshell/ifcopenshell_wrapper.pyi

@@ -1697,10 +1697,16 @@ class uninitialized_tag: ...
 
 def arrange_polygons(settings, polygons): ...
 def clear_schemas(): ...
-def construct_iterator(geometry_library, settings, file, num_threads): ...
-def construct_iterator_with_include_exclude(geometry_library, settings, file, elems, include, num_threads): ...
-def construct_iterator_with_include_exclude_globalid(geometry_library, settings, file, elems, include, num_threads): ...
-def construct_iterator_with_include_exclude_id(geometry_library, settings, file, elems, include, num_threads): ...
+def construct_iterator(geometry_library, settings, file, num_threads, logger=...): ...
+def construct_iterator_with_include_exclude(
+    geometry_library, settings, file, elems, include, num_threads, logger=...
+): ...
+def construct_iterator_with_include_exclude_globalid(
+    geometry_library, settings, file, elems, include, num_threads, logger=...
+): ...
+def construct_iterator_with_include_exclude_id(
+    geometry_library, settings, file, elems, include, num_threads, logger=...
+): ...
 def convert_loop_to_function_item(loop): ...
 def create_box(*args): ...
 def create_epeck(*args): ...
@@ -1717,8 +1723,8 @@ def line_segments_to_polygons(s, eps, segments): ...
 def map_shape(settings, instance): ...
 def nary_union(sequence): ...
 def new_IfcBaseClass(schema_identifier: str, name: str) -> entity_instance: ...
-def open(fn: str, readonly: bool = False) -> file: ...
-def parse_ifcxml(filename): ...
+def open(fn: str, readonly: bool = False, logger=...) -> file: ...
+def parse_ifcxml(filename, logger=...): ...
 def polygons_to_svg(*args): ...
 def read(data): ...
 def register_schema(arg1): ...

src/ifcopenshell-python/ifcopenshell/util/alignment.py

@@ -56,7 +56,7 @@ def append_zero_length_segments(file: ifcopenshell.file) -> ifcopenshell.file:
     for alignment in alignments:
         layouts = ifcopenshell.api.alignment.get_alignment_layouts(alignment)
         for layout in layouts:
-            ifcopenshell.api.alignment.add_zero_length_segment(patched_file, layout, include_referent=False)
+            ifcopenshell.api.alignment.add_zero_length_segment(patched_file, layout)
             curve = ifcopenshell.api.alignment.get_layout_curve(layout)
             if curve:
                 ifcopenshell.api.alignment.add_zero_length_segment(patched_file, curve)

src/ifcopenshell-python/ifcopenshell/util/cost.py

@@ -355,8 +355,7 @@ def get_cost_rate(
 
 class CostValueUnserialiser:
     def parse(self, formula: str):
-        l = lark.Lark(
-            """start: formula
+        l = lark.Lark("""start: formula
                     formula: operand (operator operand)*
                     operand: value | category "(" formula ")"
                     value: NUMBER?
@@ -393,8 +392,7 @@ class CostValueUnserialiser:
                     NEWLINE: (CR? LF)+
 
                     %ignore WS // Disregard spaces in text
-                 """
-        )
+                 """)
         start = l.parse(formula)
         return self.get_formula(start.children[0])
 

src/ifcopenshell-python/ifcopenshell/util/selector.py

@@ -39,8 +39,7 @@ import ifcopenshell.util.shape
 import ifcopenshell.util.system
 import ifcopenshell.util.unit
 
-filter_elements_grammar = lark.Lark(
-    """start: filter_group
+filter_elements_grammar = lark.Lark("""start: filter_group
     filter_group: facet_list ("+" facet_list)*
     facet_list: facet ("," facet)*
 
@@ -111,11 +110,9 @@ filter_elements_grammar = lark.Lark(
     NEWLINE: (CR? LF)+
 
     %ignore WS // Disregard spaces in text
-"""
-)
+""")
 
-get_element_grammar = lark.Lark(
-    """start: keys
+get_element_grammar = lark.Lark("""start: keys
 
     keys: key ("." key)*
     key: quoted_string | regex_string | unquoted_string
@@ -130,11 +127,9 @@ get_element_grammar = lark.Lark(
     WS: /[ \\t\\f\\r\\n]/+
 
     %ignore WS // Disregard spaces in text
- """
-)
+ """)
 
-format_grammar = lark.Lark(
-    """start: expression
+format_grammar = lark.Lark("""start: expression
 
     ?expression: add_sub
     ?add_sub: mul_div
@@ -193,8 +188,7 @@ format_grammar = lark.Lark(
     NEWLINE: (CR? LF)+
 
     %ignore WS // Disregard spaces in text
-"""
-)
+""")
 
 
 class FormatTransformer(lark.Transformer):

src/ifcopenshell-python/test/api/alignment/test_add_positioning_referent.py

@@ -0,0 +1,100 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2025 Thomas Krijnen <thomas@aecgeeks.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import ifcopenshell.api.alignment
+import ifcopenshell.api.context
+import ifcopenshell.api.unit
+import ifcopenshell.util.element
+
+
+def test_add_positioning_referent():
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_si_unit(file, unit_type="LENGTHUNIT")
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    geometric_representation_context = ifcopenshell.api.context.add_context(file, context_type="Model")
+    axis_model_representation_subcontext = ifcopenshell.api.context.add_context(
+        file,
+        context_type="Model",
+        context_identifier="Axis",
+        target_view="MODEL_VIEW",
+        parent=geometric_representation_context,
+    )
+
+    alignment = ifcopenshell.api.alignment.create(file, "TestAlignment", start_station=2000.0)
+
+    horizontal_layout = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
+    segment = ifcopenshell.api.alignment.get_layout_segments(horizontal_layout)[0]
+
+    referent = ifcopenshell.api.alignment.add_positioning_referent(
+        file, "P.C.", alignment, distance_along=0.0, station=2000.0, positioned_product=segment
+    )
+
+    assert referent.is_a("IfcReferent")
+    assert referent.PredefinedType == "POSITION"
+    assert referent.Name == "P.C."
+    assert ifcopenshell.util.element.get_pset(element=referent, name="Pset_Stationing")
+    assert ifcopenshell.util.element.get_pset(element=referent, name="Pset_Stationing", prop="Station") == 2000.0
+    assert referent.ObjectPlacement != None
+
+    assert len(referent.Positions) == 1
+    rel_positions = referent.Positions[0]
+    assert rel_positions.is_a("IfcRelPositions")
+    assert rel_positions.RelatingPositioningElement == referent
+    assert rel_positions.RelatedProducts == (segment,)
+
+
+def test_add_positioning_referent_creates_separate_referent_per_call():
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_si_unit(file, unit_type="LENGTHUNIT")
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    geometric_representation_context = ifcopenshell.api.context.add_context(file, context_type="Model")
+    axis_model_representation_subcontext = ifcopenshell.api.context.add_context(
+        file,
+        context_type="Model",
+        context_identifier="Axis",
+        target_view="MODEL_VIEW",
+        parent=geometric_representation_context,
+    )
+
+    alignment = ifcopenshell.api.alignment.create(file, "TestAlignment", start_station=2000.0)
+
+    horizontal_layout = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
+    segment = ifcopenshell.api.alignment.get_layout_segments(horizontal_layout)[0]
+
+    first_referent = ifcopenshell.api.alignment.add_positioning_referent(
+        file, "P.C.", alignment, distance_along=0.0, station=2000.0, positioned_product=segment
+    )
+
+    other_product = file.createIfcBuildingElementProxy(GlobalId=ifcopenshell.guid.new(), Name="Sign")
+    second_referent = ifcopenshell.api.alignment.add_positioning_referent(
+        file, "P.C.", alignment, distance_along=0.0, station=2000.0, positioned_product=other_product
+    )
+
+    # each call creates its own IfcReferent, each with its own IfcRelPositions to the product passed in
+    assert first_referent != second_referent
+    assert len(first_referent.Positions) == 1
+    assert first_referent.Positions[0].RelatedProducts == (segment,)
+    assert len(second_referent.Positions) == 1
+    assert second_referent.Positions[0].RelatedProducts == (other_product,)
+
+
+test_add_positioning_referent()
+test_add_positioning_referent_creates_separate_referent_per_call()

src/ifcopenshell-python/test/api/alignment/test_add_stationing_referent.py

@@ -0,0 +1,115 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2025 Thomas Krijnen <thomas@aecgeeks.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import ifcopenshell.api.alignment
+import ifcopenshell.api.context
+import ifcopenshell.api.unit
+import ifcopenshell.util.element
+
+
+def _create_test_file():
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_si_unit(file, unit_type="LENGTHUNIT")
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    geometric_representation_context = ifcopenshell.api.context.add_context(file, context_type="Model")
+    axis_model_representation_subcontext = ifcopenshell.api.context.add_context(
+        file,
+        context_type="Model",
+        context_identifier="Axis",
+        target_view="MODEL_VIEW",
+        parent=geometric_representation_context,
+    )
+    return file
+
+
+def _create_test_alignment_with_vertical(file):
+    # include_vertical=True so that get_curve() (IfcGradientCurve, on the "Axis" representation)
+    # and get_basis_curve() (IfcCompositeCurve, on the "FootPrint" representation) are different
+    # entities, letting the on_basis_curve option be observed.
+    alignment = ifcopenshell.api.alignment.create(file, "TestAlignment", include_vertical=True, start_station=0.0)
+    assert ifcopenshell.api.alignment.get_basis_curve(alignment).is_a("IfcCompositeCurve")
+    assert ifcopenshell.api.alignment.get_curve(alignment).is_a("IfcGradientCurve")
+    assert ifcopenshell.api.alignment.get_basis_curve(alignment) != ifcopenshell.api.alignment.get_curve(alignment)
+    return alignment
+
+
+def _assert_common_referent_asserts(referent, name, station):
+    assert referent.is_a("IfcReferent")
+    assert referent.PredefinedType == "STATION"
+    assert referent.Name == name
+    assert ifcopenshell.util.element.get_pset(element=referent, name="Pset_Stationing")
+    assert ifcopenshell.util.element.get_pset(element=referent, name="Pset_Stationing", prop="Station") == station
+    assert referent.ObjectPlacement != None
+
+
+def test_add_stationing_referent_on_basis_curve_none_defaults_to_basis_curve():
+    # on_basis_curve=None should behave the same as on_basis_curve=True
+    file = _create_test_file()
+    alignment = _create_test_alignment_with_vertical(file)
+
+    referent = ifcopenshell.api.alignment.add_stationing_referent(
+        file, "1+00.000", alignment, distance_along=100.0, station=100.0, on_basis_curve=None
+    )
+
+    _assert_common_referent_asserts(referent, "1+00.000", 100.0)
+
+    assert referent.ObjectPlacement.is_a("IfcLinearPlacement")
+    assert referent.ObjectPlacement.RelativePlacement.Location.BasisCurve == ifcopenshell.api.alignment.get_basis_curve(
+        alignment
+    )
+
+
+def test_add_stationing_referent_on_basis_curve_true():
+    file = _create_test_file()
+    alignment = _create_test_alignment_with_vertical(file)
+
+    referent = ifcopenshell.api.alignment.add_stationing_referent(
+        file, "1+00.000", alignment, distance_along=100.0, station=100.0, on_basis_curve=True
+    )
+
+    _assert_common_referent_asserts(referent, "1+00.000", 100.0)
+
+    assert referent.ObjectPlacement.is_a("IfcLinearPlacement")
+    assert referent.ObjectPlacement.RelativePlacement.Location.BasisCurve == ifcopenshell.api.alignment.get_basis_curve(
+        alignment
+    )
+
+
+def test_add_stationing_referent_on_basis_curve_false():
+    # with a vertical layout present, on_basis_curve=False positions the referent on the
+    # alignment curve (IfcGradientCurve) rather than on the basis curve (IfcCompositeCurve).
+    file = _create_test_file()
+    alignment = _create_test_alignment_with_vertical(file)
+
+    referent = ifcopenshell.api.alignment.add_stationing_referent(
+        file, "1+00.000", alignment, distance_along=100.0, station=100.0, on_basis_curve=False
+    )
+
+    _assert_common_referent_asserts(referent, "1+00.000", 100.0)
+
+    assert referent.ObjectPlacement.is_a("IfcLinearPlacement")
+    basis_curve = referent.ObjectPlacement.RelativePlacement.Location.BasisCurve
+    assert basis_curve == ifcopenshell.api.alignment.get_curve(alignment)
+    assert basis_curve != ifcopenshell.api.alignment.get_basis_curve(alignment)
+
+
+test_add_stationing_referent_on_basis_curve_none_defaults_to_basis_curve()
+test_add_stationing_referent_on_basis_curve_true()
+test_add_stationing_referent_on_basis_curve_false()

src/ifcopenshell-python/test/api/alignment/test_add_stationing_to_alignment.py

@@ -48,5 +48,26 @@ def test_add_stationing_to_alignment():
     assert ifcopenshell.util.element.get_pset(element=referent, name="Pset_Stationing", prop="Station") == 2000.0
     assert referent.ObjectPlacement != None
 
+    # add a station equation at 1000 distance along. this is station 3+000 in coming and 4+000 outgoing.
+    # this is a gap equation.
+    second_referent = ifcopenshell.api.alignment.add_stationing_referent(
+        file, "4+000.000", alignment, distance_along=1000.0, station=4000.0, incoming_station=3000.0
+    )
+
+    referent_nest = ifcopenshell.api.alignment.get_referent_nest(file, alignment)
+    assert len(referent_nest.RelatedObjects) == 2
+
+    assert second_referent == referent_nest.RelatedObjects[1]
+
+    assert second_referent.PredefinedType == "STATION"
+    assert second_referent.Name == "4+000.000"
+    assert ifcopenshell.util.element.get_pset(element=second_referent, name="Pset_Stationing")
+    assert ifcopenshell.util.element.get_pset(element=second_referent, name="Pset_Stationing", prop="Station") == 4000.0
+    assert (
+        ifcopenshell.util.element.get_pset(element=second_referent, name="Pset_Stationing", prop="IncomingStation")
+        == 3000.0
+    )
+    assert second_referent.ObjectPlacement != None
+
 
 test_add_stationing_to_alignment()

src/ifcopenshell-python/test/api/alignment/test_create_representation.py

@@ -21,9 +21,12 @@ import math
 
 import pytest
 import ifcopenshell
+import ifcopenshell.api.aggregate
 import ifcopenshell.api.alignment
+import ifcopenshell.api.context
+import ifcopenshell.api.spatial
 import ifcopenshell.api.unit
-import numpy as np
+import ifcopenshell.util.unit
 
 
 def test_create_representation():

src/ifcopenshell-python/test/api/alignment/test_distance_along_from_station.py

@@ -53,4 +53,56 @@ def test_distance_along_from_station():
     assert ifcopenshell.api.alignment.distance_along_from_station(file, alignment, 17525.36) == pytest.approx(7525.36)
 
 
+def test_distance_along_from_station_with_station_equations():
+    # Reproduces the worked example from the IFC Alignment Geometry Implementation Guide, chapter 9.2.6:
+    # a gap equation (P3: incoming 14+00.00, outgoing 17+00.00) and an overlap equation
+    # (P4: incoming 19+00.00, outgoing 18+50.00).
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_conversion_based_unit(file, name="foot")
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    geometric_representation_context = ifcopenshell.api.context.add_context(file, context_type="Model")
+    axis_model_representation_subcontext = ifcopenshell.api.context.add_context(
+        file,
+        context_type="Model",
+        context_identifier="Axis",
+        target_view="MODEL_VIEW",
+        parent=geometric_representation_context,
+    )
+
+    coordinates = [(500.0, 2500.0), (3340.0, 660.0), (4340.0, 5000.0), (7600.0, 4560.0), (8480.0, 2010.0)]
+    radii = [(1000.0), (1250.0), (950.0)]
+    vpoints = [(0.0, 100.0), (2000.0, 135.0), (5000.0, 105.0), (7400.0, 153.0), (9800.0, 105.0), (12800.0, 90.0)]
+    lengths = [(1600.0), (1200.0), (2000.0), (800.0)]
+
+    alignment = ifcopenshell.api.alignment.create_by_pi_method(
+        file, "TestAlignment", coordinates, radii, vpoints, lengths, start_station=1000.0
+    )
+
+    ifcopenshell.api.alignment.add_stationing_referent(
+        file, "P3", alignment, distance_along=400.0, station=1700.0, incoming_station=1400.0
+    )
+    ifcopenshell.api.alignment.add_stationing_referent(
+        file, "P4", alignment, distance_along=600.0, station=1850.0, incoming_station=1900.0
+    )
+
+    distance_along_from_station = ifcopenshell.api.alignment.distance_along_from_station
+
+    # between P2 and P3: Sta. 13+00.00
+    assert distance_along_from_station(file, alignment, 1300.0) == pytest.approx(300.0)
+
+    # between P3 and P4: Sta. 18+00.00
+    assert distance_along_from_station(file, alignment, 1800.0) == pytest.approx(500.0)
+
+    # between P4 and P5: Sta. 19+25.00
+    assert distance_along_from_station(file, alignment, 1925.0) == pytest.approx(675.0)
+
+    # Sta. 15+00.00 falls inside the gap opened by the equation at P3 and has no corresponding distance along
+    assert distance_along_from_station(file, alignment, 1500.0) is None
+
+    # Sta. 18+75.00 falls inside the overlap zone at P4; the post-equation (outgoing) match is returned
+    assert distance_along_from_station(file, alignment, 1875.0) == pytest.approx(625.0)
+
+
 test_distance_along_from_station()
+test_distance_along_from_station_with_station_equations()

src/ifcopenshell-python/test/test_parse.py

@@ -1,5 +1,6 @@
 import ifcopenshell
 
+
 def test_skip_over_non_entity_instance():
     data = """
 ISO-10303-21;

src/ifcopenshell-python/test/test_rules.py

@@ -46,4 +46,4 @@ def test_file(filename):
 
 
 if __name__ == "__main__":
-    pytest.main(["-sx", __file__, '--import-mode=importlib'])
+    pytest.main(["-sx", __file__, "--import-mode=importlib"])

src/ifcpatch/ifcpatch/recipes/ExtractElements.py

@@ -111,7 +111,7 @@ class Patcher(ifcpatch.BasePatcher):
         if element.is_a("IfcProject"):
             proj = self.new.add(element)
             for ctx in element.RepresentationContexts or ():
-                for coop in getattr(ctx, 'HasCoordinateOperation', ()):
+                for coop in getattr(ctx, "HasCoordinateOperation", ()):
                     self.new.add(coop)
             return proj
         return ifcopenshell.api.project.append_asset(

src/ifcpatch/test/test_DowngradeIndexedPolyCurve.py

@@ -33,9 +33,7 @@ class TestDowngradeIndexedPolyCurve(test.bootstrap.IFC4):
             Points=point_list,
             Segments=segments,
         )
-        self.file.create_entity(
-            "IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve
-        )
+        self.file.create_entity("IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve)
         return curve
 
     def test_run_without_segments(self):
@@ -80,9 +78,7 @@ class TestDowngradeIndexedPolyCurve(test.bootstrap.IFC4):
             Points=point_list,
             Segments=[self.file.createIfcLineIndex((1, 2, 3, 4, 1))],
         )
-        self.file.create_entity(
-            "IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve
-        )
+        self.file.create_entity("IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve)
         ifcpatch.execute(
             {"input": "input.ifc", "file": self.file, "recipe": "DowngradeIndexedPolyCurve", "arguments": []}
         )
@@ -110,9 +106,7 @@ class TestDowngradeIndexedPolyCurve(test.bootstrap.IFC4):
                 self.file.createIfcLineIndex((3, 4)),
             ],
         )
-        self.file.create_entity(
-            "IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve
-        )
+        self.file.create_entity("IfcArbitraryClosedProfileDef", ProfileType="AREA", OuterCurve=curve)
         ifcpatch.execute(
             {"input": "input.ifc", "file": self.file, "recipe": "DowngradeIndexedPolyCurve", "arguments": []}
         )

src/ifcwrap/IfcGeomWrapper.i

@@ -977,12 +977,14 @@ struct ShapeRTTI : public boost::static_visitor<PyObject*>
 			if (item == nullptr) {
 				throw IfcParse::IfcException("Failed to convert placement");
 			}
+			/*
             if (st.get<ifcopenshell::geometry::settings::ConvertBackUnits>().get()) {
                 // we pass the settings to the Transformation object, but access the data just offloads to the
                 // generic cartesian_base<Matrix4> so there's no time to apply the settings to the translation part.
                 item = ifcopenshell::geometry::taxonomy::matrix4::ptr(item->clone_());
                 item->components().col(3).head<3>() /= kernel.settings().get<ifcopenshell::geometry::settings::LengthUnit>().get();
             }
+			*/
 			return new IfcGeom::Transformation(kernel.settings(), item);
 		} else {
 			if (!representation) {

src/serializers/WavefrontObjSerializer.cpp

@@ -33,6 +33,7 @@ WaveFrontOBJSerializer::WaveFrontOBJSerializer(const stream_or_filename& obj_fil
 	, mtl_stream(mtl_filename)
 	, vcount_total(1)
 	, ncount_total(1)
+	, uvcount_total(1)
 {
 	obj_stream.stream << std::setprecision(settings.get<ifcopenshell::geometry::settings::FloatingPointDigits>().get());
 	mtl_stream.stream << std::setprecision(settings.get<ifcopenshell::geometry::settings::FloatingPointDigits>().get());
@@ -96,6 +97,7 @@ void WaveFrontOBJSerializer::write(const IfcGeom::TriangulationElement* o)
 
 	size_t vcount = mesh.verts().size() / 3;
     size_t ncount = mesh.normals().size() / 3;
+    size_t uvcount = mesh.uvs().size() / 2;
 
 	for (auto it = mesh.verts().begin(); it != mesh.verts().end();) {
         const double x = *(it++);
@@ -151,9 +153,12 @@ void WaveFrontOBJSerializer::write(const IfcGeom::TriangulationElement* o)
         const int n3 = v3 - vcount_total + ncount_total;
 
         if (has_normals && has_uvs) {
-			obj_stream.stream << "f " << v1 << "/" << n1 << "/" << n1 << " "
-				<< v2 << "/" << n2 << "/" << n2 << " "
-				<< v3 << "/" << n3 << "/" << n3 << "\n";
+			const int t1 = v1 - vcount_total + uvcount_total;
+			const int t2 = v2 - vcount_total + uvcount_total;
+			const int t3 = v3 - vcount_total + uvcount_total;
+			obj_stream.stream << "f " << v1 << "/" << t1 << "/" << n1 << " "
+				<< v2 << "/" << t2 << "/" << n2 << " "
+				<< v3 << "/" << t3 << "/" << n3 << "\n";
 		} else if (has_normals) {
             obj_stream.stream << "f " << v1 << "//" << n1 << " "
 				<< v2 << "//" << n2 << " "
@@ -196,4 +201,5 @@ void WaveFrontOBJSerializer::write(const IfcGeom::TriangulationElement* o)
 
 	vcount_total += vcount;
     ncount_total += ncount;
+    uvcount_total += uvcount;
 }

src/serializers/WavefrontObjSerializer.h

@@ -32,7 +32,7 @@ class SERIALIZERS_API WaveFrontOBJSerializer : public WriteOnlyGeometrySerialize
 private:
 	stream_or_filename obj_stream;
 	stream_or_filename mtl_stream;
-	size_t vcount_total, ncount_total;
+	size_t vcount_total, ncount_total, uvcount_total;
 	std::set<std::string> materials;
 public:
 	WaveFrontOBJSerializer(const stream_or_filename& obj_filename, const stream_or_filename& mtl_filename, const ifcopenshell::geometry::Settings& geometry_settings, const ifcopenshell::geometry::SerializerSettings& settings, Logger& logger = Logger::Root());