More robust processing of IfcPolyline and IfcPolyLoop

src/ifcgeom/IfcGeom.h

@@ -36,6 +36,7 @@
 #include <TopoDS_Face.hxx>
 #include <Geom_Curve.hxx>
 #include <gp_Pln.hxx>
+#include <TColgp_SequenceOfPnt.hxx>
 
 #include "../ifcparse/IfcParse.h"
 #include "../ifcparse/IfcUtil.h"
@@ -103,7 +104,7 @@ namespace IfcGeom {
 	void SetValue(GeomValue var, double value);
 	double GetValue(GeomValue var);
 	Ifc2x3::IfcProductDefinitionShape* tesselate(TopoDS_Shape& shape, double deflection, IfcEntities es);
-
+	void remove_redundant_points_from_loop(TColgp_SequenceOfPnt& polygon, bool closed, double tol=-1.);
 	
 	
 	namespace Cache {

src/ifcgeom/IfcGeomFunctions.cpp

@@ -574,4 +574,28 @@ Ifc2x3::IfcProductDefinitionShape* IfcGeom::tesselate(TopoDS_Shape& shape, doubl
 	es->push(shapedef);
 
 	return shapedef;
+}
+
+void IfcGeom::remove_redundant_points_from_loop(TColgp_SequenceOfPnt& polygon, bool closed, double tol) {
+	if (tol <= 0.) tol = GetValue(GV_POINT_EQUALITY_TOLERANCE);
+	tol *= tol;
+
+	while (true) {
+		bool removed = false;
+		int n = polygon.Length() - (closed ? 0 : 1);
+		for (int i = 1; i <= n; ++i) {
+			// wrap around to the first point in case of a closed loop
+			int j = (i % polygon.Length()) + 1;
+			double dist = polygon.Value(i).SquareDistance(polygon.Value(j));
+			if (dist < tol) {
+				// do not remove the first or last point to
+				// maintain connectivity with other wires
+				if ((closed && j == 1) || (!closed && j == n)) polygon.Remove(i);
+				else polygon.Remove(j);
+				removed = true;
+				break;
+			}
+		}
+		if (!removed) break;
+	}
 }

src/ifcgeom/IfcGeomShapes.cpp

@@ -221,7 +221,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 		builder.SetMinTolerance(GetValue(GV_POINT_EQUALITY_TOLERANCE));
 		for( Ifc2x3::IfcFace::it it = faces->begin(); it != faces->end(); ++ it ) {
 			TopoDS_Face face;
-			if ( IfcGeom::convert_face(*it,face) && face_area(face) > GetValue(GV_MINIMAL_FACE_AREA) ) {
+			bool converted_face = false;
+			try {
+				converted_face = IfcGeom::convert_face(*it,face);
+			} catch (...) {}
+			if ( converted_face && face_area(face) > GetValue(GV_MINIMAL_FACE_AREA) ) {
 				builder.Add(face);
 				facesAdded = true;
 			} else {
@@ -229,9 +233,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 			}
 		}
 		if ( ! facesAdded ) return false;
-		builder.Perform();
+		try {
-		shape = builder.SewedShape();
+			builder.Perform();
-		valid_shell = BRepCheck_Analyzer(shape).IsValid();
+			shape = builder.SewedShape();
+			valid_shell = BRepCheck_Analyzer(shape).IsValid();
+		} catch(...) {}
 		if (valid_shell) {
 			try {
 				ShapeFix_Solid solid;
@@ -244,6 +250,8 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 					} catch (...) {}
 				}
 			} catch(...) {}
+		} else {
+			Logger::Message(Logger::LOG_WARNING,"Failed to sew faceset:",l->entity);
 		}
 	}
 	if (!valid_shell) {
@@ -252,7 +260,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 		builder.MakeCompound(compound);
 		for( Ifc2x3::IfcFace::it it = faces->begin(); it != faces->end(); ++ it ) {
 			TopoDS_Face face;
-			if ( IfcGeom::convert_face(*it,face) && face_area(face) > GetValue(GV_MINIMAL_FACE_AREA) ) {
+			bool converted_face = false;
+			try {
+				converted_face = IfcGeom::convert_face(*it,face);
+			} catch (...) {}
+			if ( converted_face && face_area(face) > GetValue(GV_MINIMAL_FACE_AREA) ) {
 				builder.Add(compound,face);
 				facesAdded = true;
 			} else {

src/ifcgeom/IfcGeomWires.cpp

@@ -262,13 +262,20 @@ bool IfcGeom::convert(const Ifc2x3::IfcTrimmedCurve::ptr l, TopoDS_Wire& wire) {
 bool IfcGeom::convert(const Ifc2x3::IfcPolyline::ptr l, TopoDS_Wire& result) {
 	Ifc2x3::IfcCartesianPoint::list points = l->Points();
 
-	BRepBuilderAPI_MakeWire w;
+	// Parse and store the points in a sequence
-	gp_Pnt P1;gp_Pnt P2;
+	TColgp_SequenceOfPnt polygon;
-	for( Ifc2x3::IfcCartesianPoint::it it = points->begin(); it != points->end(); ++ it ) {
+	for(Ifc2x3::IfcCartesianPoint::it it = points->begin(); it != points->end(); ++ it) {
-		IfcGeom::convert(*it,P2);
+		gp_Pnt pnt;
-		if ( it != points->begin() && ( !P1.IsEqual(P2,GetValue(GV_POINT_EQUALITY_TOLERANCE)) ) )
+		IfcGeom::convert(*it, pnt);
-			w.Add(BRepBuilderAPI_MakeEdge(P1,P2));
+		polygon.Append(pnt);
-		P1 = P2;
+	}
+
+	// Remove points that are too close to one another
+	remove_redundant_points_from_loop(polygon, false);
+
+	BRepBuilderAPI_MakePolygon w;
+	for (int i = 1; i <= polygon.Length(); ++i) {
+		w.Add(polygon.Value(i));
 	}
 
 	result = w.Wire();
@@ -277,23 +284,41 @@ bool IfcGeom::convert(const Ifc2x3::IfcPolyline::ptr l, TopoDS_Wire& result) {
 bool IfcGeom::convert(const Ifc2x3::IfcPolyLoop::ptr l, TopoDS_Wire& result) {
 	Ifc2x3::IfcCartesianPoint::list points = l->Polygon();
 
-	BRepBuilderAPI_MakeWire w;
+	// Parse and store the points in a sequence
-	gp_Pnt P1;gp_Pnt P2;gp_Pnt F;
+	TColgp_SequenceOfPnt polygon;
-	int count = 0;
+	for(Ifc2x3::IfcCartesianPoint::it it = points->begin(); it != points->end(); ++ it) {
-	for( Ifc2x3::IfcCartesianPoint::it it = points->begin(); it != points->end(); ++ it ) {
+		gp_Pnt pnt;
-		IfcGeom::convert(*it,P2);
+		IfcGeom::convert(*it, pnt);
-		if ( it != points->begin() && ( !P1.IsEqual(P2,GetValue(GV_POINT_EQUALITY_TOLERANCE)) ) ) {
+		polygon.Append(pnt);
-			w.Add(BRepBuilderAPI_MakeEdge(P1,P2));
-			count ++;
-		} else if ( ! count ) F = P2;		
-		P1 = P2;
 	}
-	if ( !P1.IsEqual(F,GetValue(GV_POINT_EQUALITY_TOLERANCE)) ) {
-		w.Add(BRepBuilderAPI_MakeEdge(P1,F));
-		count ++;
-	}
-	if ( count < 3 ) return false;
 
-	result = w.Wire();
+	// A loop should consist of at least three vertices
+	int original_count = polygon.Length();
+	if (original_count < 3) {
+		Logger::Message(Logger::LOG_ERROR, "Not enough edges for:", l->entity);
+		return false;
+	}
+
+	// Remove points that are too close to one another
+	remove_redundant_points_from_loop(polygon, true);
+
+	int count = polygon.Length();
+	if (original_count - count != 0) {
+		std::stringstream ss; ss << (original_count - count) << " edges removed for:"; 
+		Logger::Message(Logger::LOG_WARNING, ss.str(), l->entity);
+	}
+
+	if (count < 3) {
+		Logger::Message(Logger::LOG_ERROR, "Not enough edges for:", l->entity);
+		return false;
+	}
+
+	BRepBuilderAPI_MakePolygon w;
+	for (int i = 1; i <= polygon.Length(); ++i) {
+		w.Add(polygon.Value(i));
+	}
+	w.Close();
+
+	result = w.Wire();	
 	return true;
 }