Don't use IfcMappedItems for IfcOpenHouse walls, as suggested by Ian Clévy in https://sourceforge.net/p/ifcopenshell/discussion/1782716/thread/f9b586ca/?limit=25#ab87

aothms · aothms · commit 44ddc5e6dc30 · 2015-10-09T14:23:38.000+02:00
diff --git a/src/examples/IfcOpenHouse.cpp b/src/examples/IfcOpenHouse.cpp
@@ -195,43 +195,46 @@ int main(int argc, char** argv) {
 	file.addBuildingProduct(north_wall);
 	file.setSurfaceColour(north_wall->Representation(), wall_colour);
 
-	IfcSchema::IfcShapeRepresentation* clipped_wall_body_rep = file.addEmptyRepresentation();
-	file.addBox(clipped_wall_body_rep, 5000, 360, 6000);
-	// The east wall geometry is clipped using two IfcHalfSpaceSolids, created from an 
-	// 'axis 3d placement' that specifies the plane against which the geometry is clipped.
-	file.clipRepresentation(clipped_wall_body_rep, file.addPlacement3d(-2500, 0, 3000, -1, 0, 1), false);
-	file.clipRepresentation(clipped_wall_body_rep, file.addPlacement3d(2500, 0, 3000, 1, 0, 1), false);
+	// Two identical representations are created for the two remaining walls. Mapped items
+	// are not used, because it is not allowed by the standard for wall body representations.
+	// MappedItems are not allowed for Axis representations as per CV-2x3-161
+	IfcSchema::IfcProductDefinitionShape* clipped_wall_body_reps[2];
+	for (int i = 0; i < 2; ++i) {
+		IfcSchema::IfcShapeRepresentation* body = file.addEmptyRepresentation();
+		file.addBox(body, 5000, 360, 6000);
+		// The wall geometry is clipped using two IfcHalfSpaceSolids, created from an 
+		// 'axis 3d placement' that specifies the plane against which the geometry is clipped.
+		file.clipRepresentation(body, file.addPlacement3d(-2500, 0, 3000, -1, 0, 1), false);
+		file.clipRepresentation(body, file.addPlacement3d(2500, 0, 3000, 1, 0, 1), false);
+		file.setSurfaceColour(body, wall_colour);
+
+		IfcSchema::IfcShapeRepresentation* axis = file.addEmptyRepresentation("Axis", "Curve2D");
+		file.addAxis(axis, 5000);
+
+		IfcSchema::IfcRepresentation::list::ptr reps(new IfcSchema::IfcRepresentation::list);
+		reps->push(body);
+		reps->push(axis);
+		clipped_wall_body_reps[i] = new IfcSchema::IfcProductDefinitionShape(null, null, reps);
+	}
 
 	// Now create a wall on the east of the building, again starting with just a box shape
 	IfcSchema::IfcWallStandardCase* east_wall = new IfcSchema::IfcWallStandardCase(guid(), file.getSingle<IfcSchema::IfcOwnerHistory>(),
-		S("East wall"), null, null, file.addLocalPlacement(storey_placement, 4820, 2500, 0, 0, 0, 1, 0, 1, 0), file.addMappedItem(clipped_wall_body_rep), null
+		S("East wall"), null, null, file.addLocalPlacement(storey_placement, 4820, 2500, 0, 0, 0, 1, 0, 1, 0), clipped_wall_body_reps[0], null
 #ifdef USE_IFC4
 		, IfcSchema::IfcWallTypeEnum::IfcWallType_STANDARD
 #endif	
 	);
 	file.addBuildingProduct(east_wall);
 
-	file.setSurfaceColour(clipped_wall_body_rep, wall_colour);
-
 	// The east wall is copied to the west location of the house
 	IfcSchema::IfcWallStandardCase* west_wall = new IfcSchema::IfcWallStandardCase(guid(), file.getSingle<IfcSchema::IfcOwnerHistory>(),
-		S("West wall"), null, null, file.addLocalPlacement(storey_placement, -4820, 2500, 0, 0, 0, 1, 0, -1, 0), file.addMappedItem(clipped_wall_body_rep), null
+		S("West wall"), null, null, file.addLocalPlacement(storey_placement, -4820, 2500, 0, 0, 0, 1, 0, -1, 0), clipped_wall_body_reps[1], null
 #ifdef USE_IFC4
 		, IfcSchema::IfcWallTypeEnum::IfcWallType_STANDARD
 #endif	
 	);
 	file.addBuildingProduct(west_wall);
 
-	for (int i = 0; i < 2; ++i) {
-		// CV-2x3-161: MappedItems are not allowed for Axis representations
-		IfcSchema::IfcWallStandardCase* wall = i == 0 ? east_wall : west_wall;
-		IfcSchema::IfcShapeRepresentation* wall_axis_rep = file.addEmptyRepresentation("Axis", "Curve2D");
-		file.addAxis(wall_axis_rep, 5000);
-		IfcSchema::IfcRepresentation::list::ptr reps = wall->Representation()->Representations();
-		reps->push(wall_axis_rep);
-		wall->Representation()->setRepresentations(reps);
-	}
-
 	// The west wall is assigned an opening element we created for the south wall, opening elements are
 	// not shared accross building elements, even if they share the same representation. Hence, the east
 	// wall will not feature this opening.
