From 4f8b430040563e87c99112d34157e8bc32ecc252 Mon Sep 17 00:00:00 2001
From: Thomas Krijnen <t.krijnen@gmail.com>
Date: Fri, 30 Nov 2018 11:08:19 +0100
Subject: [PATCH] Improvements to faceset_helper in case of nearby verts

---
 src/ifcgeom/IfcGeom.h            | 12 +++++++-----
 src/ifcgeom/IfcGeomFaces.cpp     |  6 +++++-
 src/ifcgeom/IfcGeomFunctions.cpp | 31 +++++++++++++++++++++++++++----
 3 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/ifcgeom/IfcGeom.h b/src/ifcgeom/IfcGeom.h
index 604ff34be4..3aebe1f66d 100644
--- a/src/ifcgeom/IfcGeom.h
+++ b/src/ifcgeom/IfcGeom.h
@@ -166,22 +166,24 @@ private:
 		bool wire(const IfcSchema::IfcPolyLoop* loop, TopoDS_Wire& wire) {
 			BRep_Builder builder;
 			builder.MakeWire(wire);
-			bool valid;
+			int count = 0;
 			auto ps = loop->Polygon();
-			loop_(ps, [this, &builder, &wire, &valid](int A, int B, bool fwd) {
+			loop_(ps, [this, &builder, &wire, &count](int A, int B, bool fwd) {
 				TopoDS_Edge e;
 				if (edge(A, B, e)) {
 					if (!fwd) {
 						e.Reverse();
 					}
 					builder.Add(wire, e);
-					valid = true;
+					count += 1;
 				}
 			});
-			if (valid) {
+			if (count >= 3) {
 				wire.Closed(true);
+				return true;
+			} else {
+				return false;
 			}
-			return valid;
 		}
 	};
 
diff --git a/src/ifcgeom/IfcGeomFaces.cpp b/src/ifcgeom/IfcGeomFaces.cpp
index 278cd33711..3b30fd9eb7 100644
--- a/src/ifcgeom/IfcGeomFaces.cpp
+++ b/src/ifcgeom/IfcGeomFaces.cpp
@@ -179,7 +179,11 @@ bool IfcGeom::Kernel::convert(const IfcSchema::IfcFace* l, TopoDS_Shape& face) {
 		
 			TopoDS_Wire wire;
 			if (faceset_helper_ && loop->as<IfcSchema::IfcPolyLoop>()) {
-				faceset_helper_->wire(loop->as<IfcSchema::IfcPolyLoop>(), wire);
+				if (!faceset_helper_->wire(loop->as<IfcSchema::IfcPolyLoop>(), wire)) {
+					Logger::Message(Logger::LOG_WARNING, "Face boundary loop not included", loop);
+					delete mf;
+					return false;
+				}
 			} else if (!convert_wire(loop, wire)) {
 				Logger::Message(Logger::LOG_ERROR, "Failed to process face boundary loop", loop);
 				delete mf;
diff --git a/src/ifcgeom/IfcGeomFunctions.cpp b/src/ifcgeom/IfcGeomFunctions.cpp
index cf6681c9bc..81141fdb6c 100644
--- a/src/ifcgeom/IfcGeomFunctions.cpp
+++ b/src/ifcgeom/IfcGeomFunctions.cpp
@@ -3506,6 +3506,8 @@ namespace {
 		std::vector<int> js = tree.select_box(b, false);
 		for (int j : js) {
 			if (visited.find(j) == visited.end()) {
+				// @todo, making this recursive removes the dependence on the initial ordering, but will
+				// likely result in empty results when all vertices are within 1 eps from another point.
 				find_neighbours(tree, pnts, visited, j, eps);
 			}
 		}
@@ -3527,7 +3529,7 @@ IfcGeom::Kernel::faceset_helper::faceset_helper(Kernel* kernel, const IfcSchema:
 
 	BRep_Builder B;
 
-	const double eps = kernel->getValue(GV_PRECISION);
+	const double eps = kernel->getValue(GV_PRECISION) * 10.;
 	IfcGeom::impl::tree<int> tree;
 	{
 		int i = 0;
@@ -3549,23 +3551,44 @@ IfcGeom::Kernel::faceset_helper::faceset_helper(Kernel* kernel, const IfcSchema:
 		for (int v : vs) {
 			if (v <= i) {
 				auto pt = *(points->begin() + v);
-				vertex_mapping_.insert({pt->data().id(), i});
+				vertex_mapping_[pt->data().id()] = i;
 			}
 		}
 	}
 
 	IfcSchema::IfcPolyLoop::list::ptr loops = IfcParse::traverse((IfcUtil::IfcBaseClass*)l)->as<IfcSchema::IfcPolyLoop>();
 
+	size_t loops_removed = 0, non_manifold = 0;
+
 	for (auto& loop : *loops) {
 		auto ps = loop->Polygon();
-		loop_(ps, [&edge_use](int C, int D, bool) {
-			edge_use[{C, D}] ++;
+
+		std::vector<std::pair<int, int> > segments;
+
+		loop_(ps, [&segments](int C, int D, bool) {
+			segments.push_back({ C, D });
 		});
+
+		if (segments.size() >= 3) {
+			for (auto& p : segments) {
+				edge_use[p] ++;
+			}
+		} else {
+			loops_removed += 1;
+		}
 	}
 
 	for (auto& p : edge_use) {
 		int a, b;
 		std::tie(a, b) = p.first;
 		edges_[p.first] = BRepBuilderAPI_MakeEdge(vertices[a], vertices[b]);
+
+		if (p.second != 2) {
+			non_manifold += 1;
+		}		
+	}
+
+	if (loops_removed || non_manifold) {
+		Logger::Error(boost::lexical_cast<std::string>(loops_removed) + " loops removed and " + boost::lexical_cast<std::string>(non_manifold) + " non-manifold edges for:", l);
 	}
 }
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