From fd258a611f57c71293cdc547b5aea51397d0ce25 Mon Sep 17 00:00:00 2001
From: "mhochsteger@cerbsim.com" <mhochsteger@cerbsim.com>
Date: Mon, 17 Jan 2022 14:59:23 +0100
Subject: [PATCH 1/2] bugfix in FillCloseSurface

- don't add prisms/hexes outside of current domain
- invert them when necessary
---
 libsrc/meshing/meshfunc.cpp | 43 ++++++++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/libsrc/meshing/meshfunc.cpp b/libsrc/meshing/meshfunc.cpp
index 68dcd347..41b8ea55 100644
--- a/libsrc/meshing/meshfunc.cpp
+++ b/libsrc/meshing/meshfunc.cpp
@@ -1,3 +1,5 @@
+#include <set>
+
 #include <mystdlib.h>
 #include "meshing.hpp"
 #include "debugging.hpp"
@@ -169,8 +171,8 @@ namespace netgen
   {
       static Timer timer("FillCloseSurface"); RegionTimer rtimer(timer);
 
-      auto & mesh = md.mesh;
-      auto & identifications = mesh->GetIdentifications();
+      auto & mesh = *md.mesh;
+      auto & identifications = mesh.GetIdentifications();
       auto nmax = identifications.GetMaxNr();
 
       bool have_closesurfaces = false;
@@ -188,7 +190,7 @@ namespace netgen
 
           identifications.GetMap(identnr, map);
 
-          for(auto & sel : mesh->SurfaceElements())
+          for(auto & sel : mesh.SurfaceElements())
           {
               bool is_mapped = true;
               for(auto pi : sel.PNums())
@@ -197,28 +199,45 @@ namespace netgen
 
               if(!is_mapped)
                   continue;
-              
-              // in case we have symmetric mapping (used in csg), only map in one direction
-              if(map[map[sel[0]]] == sel[0] && map[sel[0]] < sel[0])
-                  continue;
 
-              // insert prism
+              // insert prism/hex
               auto np = sel.GetNP();
               Element el(2*np);
+              std::set<int> pis;
               for(auto i : Range(np))
               {
                   el[i] = sel[i];
                   el[i+np] = map[sel[i]];
+                  pis.insert(sel[i]);
+                  pis.insert(map[sel[i]]);
               }
 
+              // degenerate element (mapped element onto itself, might happend for surface elements connecting two identified faces)
+              if(pis.size() < 2*np)
+                  continue;
+
+              bool is_domout = md.domain == mesh.GetFaceDescriptor(sel.GetIndex()).DomainOut();
+
+              // check if new element is inside current domain
+              auto p0 = mesh[sel[0]];
+              Vec<3> n = Cross(mesh[sel[1]] - p0, mesh[sel[2]] - p0 );
+              n = is_domout ? n : -n;
+
+              if(n*(mesh[el[np]]-p0) < 0.0)
+                  continue;
+
+              if(is_domout)
+                  el.Invert();
+
               el.SetIndex(md.domain);
-              mesh->AddVolumeElement(el);
+              mesh.AddVolumeElement(el);
           }
       }
   }
 
   void CloseOpenQuads( MeshingData & md)
   {
+    static Timer t("CloseOpenQuads"); RegionTimer rt(t);
     auto & mesh = *md.mesh;
     auto domain = md.domain;
     MeshingParameters & mp = md.mp;
@@ -277,10 +296,11 @@ namespace netgen
                {
                  mesh.GetIdentifications().GetPairs (nr, connectednodes);
                  for (auto pair : connectednodes)
+                 {
                    meshing.AddConnectedPair (pair);
+                   meshing.AddConnectedPair ({pair[1], pair[0]});
+                 }
                }
-           // for (auto pair : md.connected_pairs)
-           //     meshing.AddConnectedPair (pair);
            
            for (int i = 1; i <= mesh.GetNOpenElements(); i++)
              {
@@ -539,7 +559,6 @@ namespace netgen
            if (md[i].mesh->CheckOverlappingBoundary())
              throw NgException ("Stop meshing since boundary mesh is overlapping");
          
-         // TODO: FillCloseSurface is not working with CSG closesurfaces
          if(md[i].mesh->GetGeometry()->GetGeomType() == Mesh::GEOM_OCC)
            FillCloseSurface( md[i] );
          CloseOpenQuads( md[i] );

From 3ab8808fa3a3d432dd20b8facdae758dba5cb776 Mon Sep 17 00:00:00 2001
From: Christopher Lackner <clackner@cerbsim.com>
Date: Tue, 18 Jan 2022 18:24:09 +0100
Subject: [PATCH 2/2] do not restrict mesh size on identified edges

---
 libsrc/meshing/basegeom.hpp |  2 ++
 libsrc/occ/occgenmesh.cpp   | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/libsrc/meshing/basegeom.hpp b/libsrc/meshing/basegeom.hpp
index 49bf8710..642db838 100644
--- a/libsrc/meshing/basegeom.hpp
+++ b/libsrc/meshing/basegeom.hpp
@@ -196,6 +196,8 @@ namespace netgen
     size_t GetNFaces() const { return faces.Size(); }
 
     const GeometryFace & GetFace(int i) const { return *faces[i]; }
+    const GeometryEdge & GetEdge(int i) const { return *edges[i]; }
+    const GeometryVertex & GetVertex(int i) const { return *vertices[i]; }
 
     void Clear();
 
diff --git a/libsrc/occ/occgenmesh.cpp b/libsrc/occ/occgenmesh.cpp
index 643d1d9a..606adb29 100644
--- a/libsrc/occ/occgenmesh.cpp
+++ b/libsrc/occ/occgenmesh.cpp
@@ -495,6 +495,24 @@ namespace netgen
                 continue;
               }
 
+            bool is_identified_edge = false;
+            // TODO: change to use hash value
+            const auto& gedge = geom.GetEdge(geom.edge_map.at(e.TShape()));
+            auto& v0 = gedge.GetStartVertex();
+            auto& v1 = gedge.GetEndVertex();
+            for(auto & ident : v0.identifications)
+            {
+                auto other = ident.from == &v0 ? ident.to : ident.from;
+                if(other->nr == v1.nr && ident.type == Identifications::CLOSESURFACES)
+                {
+                    is_identified_edge = true;
+                    break;
+                }
+            }
+
+            if(is_identified_edge)
+              continue;
+
             double localh = len/mparam.segmentsperedge;
             double s0, s1;