UV coordinates for triangulated face sets are now saved in IFC.

src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py

@@ -40,6 +40,7 @@ class Usecase:
             "unit_scale": None,  # A scale factor to apply for all vectors in case the unit is different
             "should_force_faceted_brep": False,  # If we should force faceted breps for meshes
             "should_force_triangulation": False,  # If we should force triangulation for meshes
+            "should_generate_uvs": False,  # If UV coordinates should also be generated
             #  Possible IFC representation classes:
             #  IfcExtrudedAreaSolid/IfcRectangleProfileDef
             #  IfcExtrudedAreaSolid/IfcCircleProfileDef
@@ -505,16 +506,43 @@ class Usecase:
 
     def create_triangulated_face_set(self):
         ifc_raw_items = [None] * self.settings["total_items"]
+        if self.settings["should_generate_uvs"]:
+            ifc_raw_uv_items = [None] * self.settings["total_items"]
         for i, value in enumerate(ifc_raw_items):
             ifc_raw_items[i] = []
+            if self.settings["should_generate_uvs"]:
+                ifc_raw_uv_items[i] = []
         for polygon in self.settings["geometry"].polygons:
             ifc_raw_items[polygon.material_index % self.settings["total_items"]].append(
                 [v + 1 for v in polygon.vertices]
             )
+            if self.settings["should_generate_uvs"]:
+                ifc_raw_uv_items[polygon.material_index % self.settings["total_items"]].append(
+                    [uv + 1 for uv in polygon.loop_indices]
+                )
+
         coordinates = self.file.createIfcCartesianPointList3D(
             [self.convert_si_to_unit(v.co) for v in self.settings["geometry"].vertices]
         )
-        items = [self.file.createIfcTriangulatedFaceSet(coordinates, None, None, i) for i in ifc_raw_items if i]
+
+        if self.settings["should_generate_uvs"]:
+            # Blender supports multiple UV layers. We don't. Too bad.
+            tex_coords = self.file.createIfcTextureVertexList(
+                [tuple(x.uv) for x in self.settings["geometry"].uv_layers[0].data]
+            )
+            items = []
+            for i, coord_index in enumerate(ifc_raw_items):
+                if not coord_index:
+                    continue
+                tex_coords_index = ifc_raw_uv_items[i]
+                face_set = self.file.createIfcTriangulatedFaceSet(coordinates, None, None, coord_index)
+                texture_map = self.file.createIfcIndexedTriangleTextureMap(
+                    MappedTo=face_set, TexCoords=tex_coords, TexCoordIndex=tex_coords_index
+                )
+                items.append(face_set)
+        else:
+            items = [self.file.createIfcTriangulatedFaceSet(coordinates, None, None, i) for i in ifc_raw_items if i]
+
         return self.file.createIfcShapeRepresentation(
             self.settings["context"],
             self.settings["context"].ContextIdentifier,