Create a compsolid shape for an extrusion of a IfcCompositeProfileDef and process the opening subtraction individually

src/ifcgeom/IfcGeomFunctions.cpp

@@ -209,6 +209,43 @@ bool IfcGeom::convert_openings(const IfcSchema::IfcProduct* entity, const IfcSch
 				original_shape_volume = shape_volume(entity_shape);
 			}
 
+			if (entity_shape.ShapeType() == TopAbs_COMPSOLID) {
+
+				// For compound solids process the subtraction for the constituent
+				// solids individually and write the result back as a compound solid.
+
+				TopoDS_CompSolid compound;
+				BRep_Builder builder;
+				builder.MakeCompSolid(compound);
+
+				TopExp_Explorer exp(entity_shape, TopAbs_SOLID);
+
+				for (; exp.More(); exp.Next()) {
+					BRepAlgoAPI_Cut brep_cut(exp.Current(), opening_shape);
+					bool added = false;
+					if ( brep_cut.IsDone() ) {
+						TopoDS_Shape brep_cut_result = brep_cut;
+						BRepCheck_Analyzer analyser(brep_cut_result);
+						bool is_valid = analyser.IsValid() != 0;
+						if (is_valid) {
+							TopExp_Explorer exp(brep_cut_result, TopAbs_SOLID);
+							for (; exp.More(); exp.Next()) {
+								builder.Add(compound, exp.Current());
+								added = true;
+							}
+						}
+					}
+					if (!added) {
+						// Add the original in case subtraction fails
+						builder.Add(compound, exp.Current());
+					} else {
+						Logger::Message(Logger::LOG_ERROR,"Failed to process subtraction:",entity->entity);
+					}
+				}
+
+				entity_shape = compound;
+
+			} else {
 				BRepAlgoAPI_Cut brep_cut(entity_shape,opening_shape);
 
 				if ( brep_cut.IsDone() ) {
@@ -230,6 +267,7 @@ bool IfcGeom::convert_openings(const IfcSchema::IfcProduct* entity, const IfcSch
 				} else {
 					Logger::Message(Logger::LOG_ERROR,"Failed to process subtraction:",entity->entity);
 				}
+			}
 
 		}
 		cut_shapes.push_back(IfcGeom::IfcRepresentationShapeItem(entity_shape, &it3->Style()));

src/ifcgeom/IfcGeomShapes.cpp

@@ -96,8 +96,9 @@
 #include "../ifcgeom/IfcGeom.h"
 
 bool IfcGeom::convert(const IfcSchema::IfcExtrudedAreaSolid* l, TopoDS_Shape& shape) {
-	TopoDS_Face face;
+	TopoDS_Shape face;
 	if ( ! IfcGeom::convert_face(l->SweptArea(),face) ) return false;
+
 	const double height = l->Depth() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	gp_Trsf trsf;
 	IfcGeom::convert(l->Position(),trsf);
@@ -105,7 +106,34 @@ bool IfcGeom::convert(const IfcSchema::IfcExtrudedAreaSolid* l, TopoDS_Shape& sh
 	gp_Dir dir;
 	convert(l->ExtrudedDirection(),dir);
 
+	shape.Nullify();
+
+	if (face.ShapeType() == TopAbs_COMPOUND) {
+		
+		// For compounds (most likely the result of a IfcCompositeProfileDef) 
+		// create a compound solid shape.
+		
+		TopExp_Explorer exp(face, TopAbs_FACE);
+		
+		TopoDS_CompSolid compound;
+		BRep_Builder builder;
+		builder.MakeCompSolid(compound);
+		
+		int num_faces_extruded = 0;
+		for (; exp.More(); exp.Next(), ++num_faces_extruded) {
+			builder.Add(compound, BRepPrimAPI_MakePrism(exp.Current(), height*dir));
+		}
+
+		if (num_faces_extruded) {
+			shape = compound;
+		}
+
+	}
+	
+	if (shape.IsNull()) {	
 		shape = BRepPrimAPI_MakePrism(face, height*dir);
+	}
+
 	shape.Move(trsf);
 	return ! shape.IsNull();
 }