Fix space generation location and IFC2X3 B-rep

Two fixes for space generation:

1. IFC2X3 schema: build_brep_space now falls back to plain
   IfcRelSpaceBoundary because IfcRelSpaceBoundary1stLevel does not exist in
   IFC2X3.

2. Geometry location: set_space_representation_from_polygon now aligns the
   IFC ObjectPlacement with the Blender object, converts base_z/planes and
   the footprint polygon to the object's local coordinate system before
   building, and fixes the base_z unit scale. The centred-cube regeneration
   test was updated to check world bounds because the mesh is now placed
   relative to the object placement.

Generated with the assistance of an AI coding tool.

src/bonsai/bonsai/tool/spatial.py

@@ -42,6 +42,7 @@ import ifcopenshell.util.type
 import ifcopenshell.util.unit
 import numpy as np
 import shapely
+import shapely.affinity
 import shapely.ops
 from mathutils import Matrix, Vector
 from natsort import natsorted
@@ -1329,7 +1330,22 @@ class Spatial(bonsai.core.tool.Spatial):
         unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
         ifc_file = tool.Ifc.get()
         x, y, z = obj.matrix_world.translation
-        base_z = z / unit_scale
+        origin = obj.matrix_world.translation  # Blender SI
+        # The space builders expect base_z and polygon in SI (world) units.
+        base_z = z
+        poly_si = poly if polygon_is_si else shapely.affinity.scale(poly, unit_scale, unit_scale, origin=(0, 0))
+
+        # Ensure the IFC entity has an ObjectPlacement matching the Blender object,
+        # so the generated representation is in the correct local coordinate system.
+        bpy.context.view_layer.update()
+        matrix = np.array(obj.matrix_world)
+        ifcopenshell.api.geometry.edit_object_placement(
+            ifc_file,
+            product=element,
+            matrix=matrix,
+            is_si=True,
+        )
+
         if cls.get_spatial_props().force_space_height:
             cls.set_extrusion_representation_from_polygon(obj, element, poly, h / unit_scale, polygon_is_si)
             return
@@ -1341,15 +1357,37 @@ class Spatial(bonsai.core.tool.Spatial):
                 for wall in ifc_file.by_type("IfcWall"):
                     if wall in ifcopenshell.util.element.get_decomposition(container):
                         bounding_walls.append(wall)
-        strategy, top_planes, bottom_planes = cls.get_space_volume_strategy(poly, base_z, bounding_walls, container)
+
+        # Detect planes in world SI (same coordinate system as the geom cache).
+        strategy, top_planes, bottom_planes = cls.get_space_volume_strategy(poly_si, base_z, bounding_walls, container)
+
+        # Build the geometry in the space's local coordinate system so the IFC
+        # representation is relative to the object's ObjectPlacement.
+        local_poly_si = shapely.affinity.translate(poly_si, -origin.x, -origin.y)
+        local_base_z = base_z - origin.z
+
+        def localize_plane(plane):
+            point, normal = plane
+            return (np.array(point) - np.array([origin.x, origin.y, origin.z]), normal)
+
+        local_top_planes = [localize_plane(p) for p in (top_planes or [])]
+        local_bottom_planes = [localize_plane(p) for p in (bottom_planes or [])]
+
         if strategy == "EXTRUDE_CLIP" and top_planes:
             item = ifcopenshell.util.space.build_extruded_clipped_space(
-                ifc_file, poly, base_z, top_planes, bottom_planes or []
+                ifc_file, local_poly_si, local_base_z, local_top_planes, local_bottom_planes
             )
             cls.set_brep_representation_from_mesh(obj, element, item)
         else:
+            shapes = cls.get_or_build_geom_cache()["shapes"]
+            local_shapes = {}
+            for shape_id, shape_data in shapes.items():
+                local_shape_data = dict(shape_data)
+                local_shape_data["top_z"] = shape_data["top_z"] - origin.z
+                local_shape_data["bottom_z"] = shape_data["bottom_z"] - origin.z
+                local_shapes[shape_id] = local_shape_data
             item = ifcopenshell.util.space.build_brep_space(
-                ifc_file, element, cls.get_or_build_geom_cache()["shapes"], poly, base_z
+                ifc_file, element, local_shapes, local_poly_si, local_base_z
             )
             if item is None:
                 cls.set_extrusion_representation_from_polygon(obj, element, poly, h / unit_scale, polygon_is_si)

src/bonsai/test/tool/test_spatial.py

@@ -26,6 +26,7 @@ import ifcopenshell.api.root
 import ifcopenshell.api.spatial
 import ifcopenshell.util.representation
 import numpy as np
+import pytest
 import shapely
 from mathutils import Matrix, Vector
 
@@ -497,11 +498,10 @@ class TestGenerateSpace(NewFile):
 
         mesh = obj.data
         assert isinstance(mesh, bpy.types.Mesh)
-        verts = [v.co.z for v in mesh.vertices]
+        world_verts = [obj.matrix_world @ v.co for v in mesh.vertices]
-        min_z = min(verts)
+        world_zs = [v.z for v in world_verts]
-        max_z = max(verts)
+        assert min(world_zs) >= -0.1, f"Expected space world bottom near z>=0, got {min(world_zs)}"
-        assert min_z >= 0, f"Expected extrusion to start at local z>=0, got min_z={min_z}"
+        assert max(world_zs) > 0, f"Expected space to have positive height, got {max(world_zs)}"
-        assert max_z > 0, f"Expected extrusion to have positive height, got max_z={max_z}"
         assert np.isclose(obj.location.z, 4.5, atol=0.01), f"Expected location.z=4.5, got {obj.location.z}"
 
 
@@ -609,4 +609,23 @@ class TestSpaceVolumeStrategy(NewFile):
         assert len(top) == 1
         assert len(bottom) == 0
 
-class TestGenerateSpaceSlopedRoof(NewFile):
+
+class TestGenerateSpaceLocation(NewFile):
+    def test_generate_space_at_non_zero_cursor_location(self):
+        bpy.ops.bim.create_project()
+        ifc = tool.Ifc.get()
+        # 4 thin walls forming a hollow box around (10, 20).
+        _BlockHelper.create_thin_wall(ifc, 10.0, 20.0 + 4.8, 10.0, 0.4)
+        _BlockHelper.create_thin_wall(ifc, 10.0, 20.0 - 4.8, 10.0, 0.4)
+        _BlockHelper.create_thin_wall(ifc, 10.0 + 4.8, 20.0, 0.4, 10.0)
+        _BlockHelper.create_thin_wall(ifc, 10.0 - 4.8, 20.0, 0.4, 10.0)
+        bpy.context.scene.cursor.location = (10, 20, 0)
+
+        bpy.ops.bim.generate_space()
+        space = bpy.data.objects["IfcSpace/Space"]
+        mesh = space.data
+        assert isinstance(mesh, bpy.types.Mesh)
+        world_verts = np.array([space.matrix_world @ v.co for v in mesh.vertices])
+        center = (world_verts.min(axis=0) + world_verts.max(axis=0)) / 2
+        assert center[0] == pytest.approx(10.0, abs=0.1)
+        assert center[1] == pytest.approx(20.0, abs=0.1)

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

@@ -565,8 +565,11 @@ def build_brep_space(
     ifcopenshell.api.geometry.assign_representation(ifc_file, product=space, representation=seed_rep)
 
     local_shapes = _build_local_shapes(ifc_file)
+    boundary_class = "IfcRelSpaceBoundary1stLevel"
+    if ifc_file.schema == "IFC2X3":
+        boundary_class = "IfcRelSpaceBoundary"
     boundaries = ifcopenshell.util.boundary.auto_generate_boundaries(
-        ifc_file, space, local_shapes, boundary_class="IfcRelSpaceBoundary1stLevel"
+        ifc_file, space, local_shapes, boundary_class=boundary_class
     )
     if isinstance(boundaries, str) or not boundaries:
         ifcopenshell.api.geometry.remove_representation(ifc_file, representation=seed_rep)

src/ifcopenshell-python/test/util/test_space.py

@@ -24,6 +24,7 @@ import ifcopenshell.util.shape
 import ifcopenshell.util.space as subject
 import math
 import numpy as np
+import os
 import pytest
 import shapely
 import test.bootstrap
@@ -320,3 +321,24 @@ class TestBuildBrepSpace(test.bootstrap.IFC4):
         item = subject.build_brep_space(self.file, space, shapes, shapely.box(-4, -4, 4, 4), 0.0)
         assert item is not None
         assert item.is_a("IfcFacetedBrep") or item.is_a("IfcPolygonalFaceSet")
+
+
+class TestBuildBrepSpaceIfc2x3:
+    def test_build_brep_space_on_ifc2x3_uses_rel_space_boundary(self):
+        # IFC2X3 does not have IfcRelSpaceBoundary1stLevel; build_brep_space must
+        # fall back to plain IfcRelSpaceBoundary without raising a schema error.
+        # We use the real IFC2X3 fixture because the installed wrapper in this
+        # environment has a quirk with synthetic IFC2X3 geometry creation.
+        path = os.path.join(
+            os.path.dirname(__file__),
+            "..",
+            "IfcRelSpaceBoundary_TestFiles",
+            "IfcRelSpaceBoundary2ndLevel",
+            "HouseWithGarage_AC22_IFC2X3.ifc",
+        )
+        ifc_file = ifcopenshell.open(path)
+        space = ifc_file.by_type("IfcSpace")[0]
+        shapes = _build_shapes_dict(ifc_file, ifc_file.by_type("IfcWall") + ifc_file.by_type("IfcSlab"))
+        item = subject.build_brep_space(ifc_file, space, shapes, shapely.box(-1, -1, 1, 1), 0.0)
+        assert item is not None
+        assert item.is_a("IfcFacetedBrep") or item.is_a("IfcPolygonalFaceSet")