Detect self-intersections in faceset helper and clamp bounding box eps factor to 1.

src/ifcgeom/IfcGeom.h

@@ -121,6 +121,7 @@ private:
 		MAKE_TYPE_NAME(Kernel)* kernel_;
 		std::map<int, int> vertex_mapping_;
 		std::map<std::pair<int, int>, TopoDS_Edge> edges_;
+		double eps_;
 
 		template <typename Fn>
 		void loop_(IfcSchema::IfcCartesianPoint::list::ptr& ps, const Fn& callback) {
@@ -184,11 +185,22 @@ private:
 			});
 			if (count >= 3) {
 				wire.Closed(true);
+
+				TopTools_ListOfShape results;
+				if (kernel_->wire_intersections(wire, results)) {
+					Logger::Error("Self-intersections with " + boost::lexical_cast<std::string>(results.Extent()) + " cycles detected", loop);
+					kernel_->select_largest(results, wire);
+				}
+
 				return true;
 			} else {
 				return false;
 			}
 		}
+
+		double epsilon() const {
+			return eps_;
+		}
 	};
 
 	double deflection_tolerance;

src/ifcgeom/IfcGeomFunctions.cpp

@@ -3300,7 +3300,9 @@ bool IfcGeom::Kernel::wire_intersections(const TopoDS_Wire& wire, TopTools_ListO
 	// TopoDS_Face face = BRepBuilderAPI_MakeFace(wire, true).Face();
 	// ShapeAnalysis_Wire saw(wd, face, getValue(GV_PRECISION));
 	
-	const double eps = (std::min)(min_edge_length(wire) / 2., getValue(GV_PRECISION) * 10.);
+	const double eps = faceset_helper_
+		? faceset_helper_->epsilon()
+		: (std::min)(min_edge_length(wire) / 2., getValue(GV_PRECISION) * 10.);
 
 	for (int i = 2; i < n; ++i) {
 
@@ -3788,14 +3790,14 @@ IfcGeom::Kernel::faceset_helper::faceset_helper(Kernel* kernel, const IfcSchema:
 		}
 	}
 
-	const double eps = kernel->getValue(GV_PRECISION) * 10. * bdiff;
+	eps_ = kernel->getValue(GV_PRECISION) * 10. * (std::min)(1.0, bdiff);
 
 	std::map<std::pair<int, int>, int> edge_use;
 
 	for (int i = 0; i < pnts.size(); ++i) {
 		if (pnts[i]) {
 			std::set<int> vs;
-			find_neighbours(tree, pnts, vs, i, eps);
+			find_neighbours(tree, pnts, vs, i, eps_);
 
 			for (int v : vs) {
 				auto pt = *(points->begin() + v);