From 2e0c2800141c3194ab72076de198791c8e3ac76b Mon Sep 17 00:00:00 2001
From: eap <eap@opencascade.com>
Date: Wed, 18 May 2005 07:29:05 +0000
Subject: [PATCH] Fix Bug PAL8787: pass to Netgen only nodes of triangles

---
 src/NETGENPlugin/NETGENPlugin_NETGEN_3D.cxx | 761 ++++----------------
 1 file changed, 151 insertions(+), 610 deletions(-)

diff --git a/src/NETGENPlugin/NETGENPlugin_NETGEN_3D.cxx b/src/NETGENPlugin/NETGENPlugin_NETGEN_3D.cxx
index 0f7eb7f..db0c493 100644
--- a/src/NETGENPlugin/NETGENPlugin_NETGEN_3D.cxx
+++ b/src/NETGENPlugin/NETGENPlugin_NETGEN_3D.cxx
@@ -10,27 +10,22 @@
 using namespace std;
 
 #include "NETGENPlugin_NETGEN_3D.hxx"
+
 #include "SMESH_Gen.hxx"
 #include "SMESH_Mesh.hxx"
-#include "SMESH_subMesh.hxx"
-
+#include "SMESH_ControlsDef.hxx"
+#include "SMESHDS_Mesh.hxx"
 #include "SMDS_MeshElement.hxx"
 #include "SMDS_MeshNode.hxx"
-#include "SMDS_FacePosition.hxx"
 
 #include <TopExp.hxx>
-#include <TopTools_IndexedDataMapOfShapeListOfShape.hxx>
-#include <TopTools_ListOfShape.hxx>
-#include <TopTools_ListIteratorOfListOfShape.hxx>
-#include <TColStd_ListIteratorOfListOfInteger.hxx>
-
-#include <BRep_Tool.hxx>
-#include <Geom_Surface.hxx>
-#include <Geom_Curve.hxx>
-#include <Geom2d_Curve.hxx>
 
 #include "utilities.h"
 
+#include <list>
+#include <vector>
+#include <map>
+
 /*
   Netgen include files
 */
@@ -100,8 +95,6 @@ bool NETGENPlugin_NETGEN_3D::CheckHypothesis
   theHyp = (*itl); // use only the first hypothesis
 
   string hypName = theHyp->GetName();
-//   int hypId = theHyp->GetID();
-//   SCRUTE(hypName);
 
   bool isOk = false;
 
@@ -132,631 +125,179 @@ bool NETGENPlugin_NETGEN_3D::Compute(SMESH_Mesh&         aMesh,
 
   SMESHDS_Mesh* meshDS = aMesh.GetMeshDS();
 
-  map<int, const SMDS_MeshNode*> netgenToDS;
+  // get a shell from aShape
+  TopoDS_Shell aShell;
+  TopExp_Explorer exp(aShape,TopAbs_SHELL);
+  if ( exp.More() )
+    aShell = TopoDS::Shell(exp.Current());
 
-  // check if all faces were meshed by a triangle mesher (here MESFISTO_2D)
+  if ( aShell.IsNull() || !aMesh.GetSubMesh( aShell )) {
+    INFOS( "NETGENPlugin_NETGEN_3D::Compute(), bad shape");
+    return false;
+  }
+  // -------------------------------------------------------------------
+  // get triangles on aShell and make a map of nodes to Netgen node IDs
+  // -------------------------------------------------------------------
 
-  vector<SMESH_subMesh*> meshFaces;
-  vector<TopoDS_Shape> shapeFaces;
+  typedef map< const SMDS_MeshNode*, int> TNodeToIDMap;
+  TNodeToIDMap nodeToNetgenID;
+  list< const SMDS_MeshElement* > triangles;
+  list< bool >                    isReversed; // orientation of triangles
+
+  SMESH::Controls::Area areaControl;
+  SMESH::Controls::TSequenceOfXYZ nodesCoords;
 
   for (TopExp_Explorer exp(aShape,TopAbs_FACE);exp.More();exp.Next())
+  {
+    TopoDS_Shape aShapeFace = exp.Current();
+    int faceID = meshDS->ShapeToIndex( aShapeFace );
+    TopoDS_Shape aMeshedFace = meshDS->IndexToShape( faceID );
+    const SMESHDS_SubMesh * aSubMeshDSFace = meshDS->MeshElements( faceID );
+    if ( aSubMeshDSFace )
     {
-      TopoDS_Shape aShapeFace = exp.Current();
-      SMESH_subMesh* aSubMesh = aMesh.GetSubMeshContaining(exp.Current());
-      ASSERT (aSubMesh);
-      int internal_size = meshFaces.size();
-      int index = 0;
-      for (int i = 0;i<internal_size;i++)
-	{
-	  if (aSubMesh == meshFaces[i]) index = 1;
-	}
-      if (index == 0) meshFaces.push_back(aSubMesh);
-
-      internal_size = shapeFaces.size();
-      index = 0;
-      for (int i = 0;i<internal_size;i++)
-	{
-	  if (aShapeFace == shapeFaces[i]) index = 1;
-	}
-      if (index == 0) shapeFaces.push_back(aShapeFace);
+      bool isRev = ( aShapeFace.Orientation() != aMeshedFace.Orientation() );
+      SMDS_ElemIteratorPtr iteratorElem = aSubMeshDSFace->GetElements();
+      while ( iteratorElem->more() ) // loop on elements on a face
+      {
+        // check element
+        const SMDS_MeshElement* elem = iteratorElem->next();
+        if ( !elem || elem->NbNodes() != 3 ) {
+          INFOS( "NETGENPlugin_NETGEN_3D::Compute(), bad mesh");
+          return false;
+        }
+        // keep a triangle
+        triangles.push_back( elem );
+        isReversed.push_back( isRev );
+        // put elem nodes to nodeToNetgenID map
+        SMDS_ElemIteratorPtr triangleNodesIt = elem->nodesIterator();
+        while ( triangleNodesIt->more() ) {
+	  const SMDS_MeshNode * node =
+            static_cast<const SMDS_MeshNode *>(triangleNodesIt->next());
+          nodeToNetgenID.insert( make_pair( node, 0 ));
+        }
+#ifdef _DEBUG_
+        // check if a trainge is degenerated
+        areaControl.GetPoints( elem, nodesCoords );
+        double area = areaControl.GetValue( nodesCoords );
+        if ( area <= DBL_MIN ) {
+          MESSAGE( "Warning: Degenerated " << elem );
+        }
+#endif
+      }
     }
+  }
+  // ---------------------------------
+  // Feed the Netgen with surface mesh
+  // ---------------------------------
 
-  int numberOfFaces = meshFaces.size();
+  int Netgen_NbOfNodes = nodeToNetgenID.size();
+  int Netgen_param2ndOrder = 0;
+  double Netgen_paramFine = 1.;
+  double Netgen_paramSize = _maxElementVolume;
 
-  int NbTotOfTria = 0;
-  int NbTotOfNodesFaces = 0;
+  double Netgen_point[3];
+  int Netgen_triangle[3];
+  int Netgen_tetrahedron[4];
 
-  for (int i=0; i<numberOfFaces; i++)
-    {
-      TopoDS_Shape aShapeFace = meshFaces[i]->GetSubShape();
-      TopoDS_Shape aFace = shapeFaces[i];
-      SMESH_Algo* algoFace = _gen->GetAlgo(aMesh, aShapeFace);
-      string algoFaceName = algoFace->GetName();
-      if (algoFaceName != "MEFISTO_2D")
-	{
-	  INFOS(algoFaceName);
-	  return false;
-	}
-
-      const SMESHDS_SubMesh* aSubMeshDSFace = meshFaces[i]->GetSubMeshDS();
-
-      int nbNodes = aSubMeshDSFace->NbNodes();
-      NbTotOfNodesFaces += nbNodes;
-      int nbTria = aSubMeshDSFace->NbElements();
-      NbTotOfTria += nbTria;
-      int index = 0;
-
-      SMDS_ElemIteratorPtr iteratorTriangle = aSubMeshDSFace->GetElements();
-
-      index = 0;
-      int numberOfDegeneratedTriangle = 0;
-      while(iteratorTriangle->more())
-	{
-	  index++;
-	  const SMDS_MeshElement * triangle = iteratorTriangle->next();
-
-	  SMDS_ElemIteratorPtr triangleNodesIt = triangle->nodesIterator();
-
-	  const SMDS_MeshNode * node1 = static_cast<const SMDS_MeshNode *>(triangleNodesIt->next());
-	  double node1X = node1->X();
-	  double node1Y = node1->Y();
-	  double node1Z = node1->Z();
-
-	  const SMDS_MeshNode * node2 = static_cast<const SMDS_MeshNode *>(triangleNodesIt->next());
-	  double node2X = node2->X();
-	  double node2Y = node2->Y();
-	  double node2Z = node2->Z();
-
-	  const SMDS_MeshNode * node3 = static_cast<const SMDS_MeshNode *>(triangleNodesIt->next());
-	  double node3X = node3->X();
-	  double node3Y = node3->Y();
-	  double node3Z = node3->Z();
-
-	  // Compute the triangle surface
-
-	  double vect1 = ((node2Y - node1Y)*(node3Z - node1Z) - (node2Z - node1Z)*(node3Y - node1Y));
-	  double vect2 = - ((node2X - node1X)*(node3Z - node1Z) - (node2Z - node1Z)*(node3X - node1X));
-	  double vect3 = ((node2X - node1X)*(node3Y - node1Y) - (node2Y - node1Y)*(node3X - node1X));
-	  double epsilon = 1.0e-6;
-
-	  bool triangleIsDegenerated = ((abs(vect1)<epsilon) && (abs(vect2)<epsilon) && (abs(vect3)<epsilon));
-
-	  if (triangleIsDegenerated)
-	    {
-	      numberOfDegeneratedTriangle++;
-	    }
-	}
-
-      if (numberOfDegeneratedTriangle > 0)
-	MESSAGE("WARNING THERE IS(ARE) " << numberOfDegeneratedTriangle << " degenerated triangle on this face");
+  Ng_Init();
 
-    }
-
-  // check if all edges were meshed by a edge mesher (here Regular_1D)
+  Ng_Mesh * Netgen_mesh = Ng_NewMesh();
 
-  vector<SMESH_subMesh*> meshEdges;
-  for (TopExp_Explorer exp(aShape,TopAbs_EDGE);exp.More();exp.Next())
-    {
-      SMESH_subMesh* aSubMesh = aMesh.GetSubMeshContaining(exp.Current());
-      ASSERT (aSubMesh);
-      int internal_size = meshEdges.size();
-      int index = 0;
-      for (int i = 0;i<internal_size;i++)
-	{
-	  if (aSubMesh == meshEdges[i]) index = 1;
-	}
-      if (index == 0) meshEdges.push_back(aSubMesh);
+  // set nodes and remember thier netgen IDs
+  TNodeToIDMap::iterator n_id = nodeToNetgenID.begin();
+  for ( int id = 0; n_id != nodeToNetgenID.end(); ++n_id )
+  {
+    const SMDS_MeshNode* node = n_id->first;
+    Netgen_point [ 0 ] = node->X();
+    Netgen_point [ 1 ] = node->Y();
+    Netgen_point [ 2 ] = node->Z();
+    n_id->second = ++id;
+    Ng_AddPoint(Netgen_mesh, Netgen_point);
+  }
+  // set triangles
+  list< const SMDS_MeshElement* >::iterator tria = triangles.begin();
+  list< bool >::iterator                 reverse = isReversed.begin();
+  for ( ; tria != triangles.end(); ++tria, ++reverse )
+  {
+    int i = 0;
+    SMDS_ElemIteratorPtr triangleNodesIt = (*tria)->nodesIterator();
+    while ( triangleNodesIt->more() ) {
+      const SMDS_MeshNode * node =
+        static_cast<const SMDS_MeshNode *>(triangleNodesIt->next());
+      Netgen_triangle[ *reverse ? 2 - i : i ] = nodeToNetgenID[ node ];
+      ++i;
     }
+    Ng_AddSurfaceElement(Netgen_mesh, NG_TRIG, Netgen_triangle);
+  }
 
-  int numberOfEdges = meshEdges.size();
-
-  int NbTotOfNodesEdges = 0;
-  int NbTotOfSegs = 0;
+  // -------------------------
+  // Generate the volume mesh
+  // -------------------------
 
-  for (int i=0; i<numberOfEdges; i++)
-    {
-      TopoDS_Shape aShapeEdge = meshEdges[i]->GetSubShape();
-      SMESH_Algo* algoEdge = _gen->GetAlgo(aMesh, aShapeEdge);
-      string algoEdgeName = algoEdge->GetName();
-      if (algoEdgeName != "Regular_1D")
-	{
-	  INFOS(algoEdgeName);
-	  ASSERT(0);
-	  return false;
-	}
-
-      const SMESHDS_SubMesh* aSubMeshDSEdge = meshEdges[i]->GetSubMeshDS();
-
-      int nbNodes = aSubMeshDSEdge->NbNodes();
-      NbTotOfNodesEdges += nbNodes;
-      int nbSegs = aSubMeshDSEdge->NbElements();
-      NbTotOfSegs += nbSegs;
-    }
+  Ng_Meshing_Parameters Netgen_param;
 
-  vector<SMESH_subMesh*> meshVertices;
-  for (TopExp_Explorer exp(aShape,TopAbs_VERTEX);exp.More();exp.Next())
-    {
-      SMESH_subMesh* aSubMesh = aMesh.GetSubMeshContaining(exp.Current());
-      ASSERT (aSubMesh);
-      int internal_size = meshVertices.size();
-      int index = 0;
-      for (int i = 0;i<internal_size;i++)
-	{
-	  if (aSubMesh == meshVertices[i]) index = 1;
-	}
-      if (index == 0) meshVertices.push_back(aSubMesh);
-    }
+  Netgen_param.secondorder = Netgen_param2ndOrder;
+  Netgen_param.fineness = Netgen_paramFine;
+  Netgen_param.maxh = Netgen_paramSize;
 
-  int numberOfVertices = meshVertices.size();
+  Ng_Result status;
 
-  int NbTotOfNodesVertices = 0;
+  try {
+    status = Ng_GenerateVolumeMesh(Netgen_mesh, &Netgen_param);
+  } catch (...) {
+    MESSAGE("An exception has been caught during the Volume Mesh Generation ...");
+    status = NG_VOLUME_FAILURE;
+  }
 
-  for (int i=0; i<numberOfVertices; i++)
-    {
-      TopoDS_Shape aShapeVertex = meshVertices[i]->GetSubShape();
+  int Netgen_NbOfNodesNew = Ng_GetNP(Netgen_mesh);
 
-      const SMESHDS_SubMesh * aSubMeshDSVertex = meshVertices[i]->GetSubMeshDS();
+  int Netgen_NbOfTetra = Ng_GetNE(Netgen_mesh);
 
-      int nbNodes = aSubMeshDSVertex->NbNodes();
-      NbTotOfNodesVertices += nbNodes;
-    }
+  MESSAGE("End of Volume Mesh Generation. status=" << status <<
+          ", nb new nodes: " << Netgen_NbOfNodesNew - Netgen_NbOfNodes <<
+          ", nb tetra: " << Netgen_NbOfTetra);
 
-  vector<SMESH_subMesh*> meshShells;
-  TopoDS_Shell aShell;
+  // -------------------------------------------------------------------
+  // Feed back the SMESHDS with the generated Nodes and Volume Elements
+  // -------------------------------------------------------------------
 
-  for (TopExp_Explorer exp(aShape,TopAbs_SHELL);exp.More();exp.Next())
+  bool isOK = ( status == NG_OK && Netgen_NbOfTetra > 0 );
+  if ( isOK )
+  {
+    // vector of nodes in which node index == netgen ID
+    vector< const SMDS_MeshNode* > nodeVec ( Netgen_NbOfNodesNew + 1 );
+    // insert old nodes into nodeVec
+    for ( n_id = nodeToNetgenID.begin(); n_id != nodeToNetgenID.end(); ++n_id )
+      nodeVec[ n_id->second ] = n_id->first;
+    // create and insert new nodes into nodeVec
+    int nodeIndex = Netgen_NbOfNodes;
+    for ( ; nodeIndex <= Netgen_NbOfNodesNew; ++nodeIndex )
     {
-      SMESH_subMesh* aSubMesh = aMesh.GetSubMesh(exp.Current());
-      ASSERT(aSubMesh);
-      aShell = TopoDS::Shell(exp.Current());
-      meshShells.push_back(aSubMesh);
+      Ng_GetPoint( Netgen_mesh, nodeIndex, Netgen_point );
+      SMDS_MeshNode * node = meshDS->AddNode(Netgen_point[0],
+                                             Netgen_point[1],
+                                             Netgen_point[2]);
+      meshDS->SetNodeInVolume(node, aShell);
+      nodeVec[nodeIndex] = node;
     }
 
-  int numberOfShells = meshShells.size();
-
-  if (numberOfShells > 0)
+    // create tetrahedrons
+    for ( int elemIndex = 1; elemIndex <= Netgen_NbOfTetra; ++elemIndex )
     {
-      /*
-	Prepare the Netgen surface mesh from the SMESHDS
-      */
-      int spaceDimension = 3;
-      int nbNodesByTri = 3;
-      int nbNodesByTetra = 4;
-
-      int Netgen_NbOfNodes = NbTotOfNodesFaces +
-	                     NbTotOfNodesEdges +
-	                     NbTotOfNodesVertices;
-      int Netgen_NbOfTria = NbTotOfTria;
-      int Netgen_param2ndOrder = 0;
-      double Netgen_paramFine = 1.;
-      double Netgen_paramSize = _maxElementVolume;
-
-      double * Netgen_Coordinates = new double [spaceDimension*
-						Netgen_NbOfNodes];
-      int * listNodeCoresNetgenSmesh = new int [Netgen_NbOfNodes];
-      int * Netgen_Connectivity = new int [nbNodesByTri*Netgen_NbOfTria];
-      double * Netgen_point = new double [spaceDimension];
-      int * Netgen_triangle = new int [nbNodesByTri];
-      int * Netgen_tetrahedron = new int [nbNodesByTetra];
-
-      for (int i=0; i<Netgen_NbOfTria; i++)
-	{
-	  for (int j=0; j<nbNodesByTri; j++)
-	    Netgen_Connectivity[i*nbNodesByTri+j] = 0;
-	}
-
-      double bigNumber = 1.e20;
-
-      for (int i=0; i<Netgen_NbOfNodes; i++)
-	{
-	  listNodeCoresNetgenSmesh[i] = 0;
-	  for (int j=0; j<spaceDimension; j++)
-	    Netgen_Coordinates[i*spaceDimension+j] = bigNumber;
-	}
-
-      int indexNodes = 0;
-      for (int i=0; i<numberOfVertices; i++)
-	{
-	  const SMESHDS_SubMesh * aSubMeshDSVertex =
-	    meshVertices[i]->GetSubMeshDS();
-
-	  SMDS_NodeIteratorPtr iteratorNodes = aSubMeshDSVertex->GetNodes();
-
-	  while(iteratorNodes->more())
-	    {
-	      const SMDS_MeshNode * node = iteratorNodes->next();
-	      int nodeId = node->GetID();
-	      double nodeX = node->X();
-	      double nodeY = node->Y();
-	      double nodeZ = node->Z();
-	      listNodeCoresNetgenSmesh[indexNodes] = nodeId;
-	      int index = indexNodes*spaceDimension;
-	      Netgen_Coordinates[index] = nodeX;
-	      Netgen_Coordinates[index+1] = nodeY;
-	      Netgen_Coordinates[index+2] = nodeZ;
-	      netgenToDS[indexNodes] = node;
-	      indexNodes++;
-	    }
-	}
-
-      for (int i=0; i<numberOfEdges; i++)
-	{
-	  const SMESHDS_SubMesh *  aSubMeshDSEdge =
-	    meshEdges[i]->GetSubMeshDS();
-
-	  SMDS_NodeIteratorPtr iteratorNodes = aSubMeshDSEdge->GetNodes();
-
-	  while(iteratorNodes->more())
-	    {
-	      const SMDS_MeshNode * node = iteratorNodes->next();
-	      listNodeCoresNetgenSmesh[indexNodes] = node->GetID();
-	      int index = indexNodes*spaceDimension;
-	      Netgen_Coordinates[index] = node->X();
-	      Netgen_Coordinates[index+1] = node->Y();
-	      Netgen_Coordinates[index+2] = node->Z();
-	      netgenToDS[indexNodes] = node;
-	      indexNodes++;
-	    }
-	}
-
-      for (int i=0; i<numberOfFaces; i++)
-	{
-	  const SMESHDS_SubMesh * aSubMeshDSFace =
-	    meshFaces[i]->GetSubMeshDS();
-
-	  SMDS_NodeIteratorPtr iteratorNodes = aSubMeshDSFace->GetNodes();
-
-	  while(iteratorNodes->more())
-	    {
-	      const SMDS_MeshNode * node = iteratorNodes->next();
-	      int nodeId = node->GetID();
-	      double nodeX = node->X();
-	      double nodeY = node->Y();
-	      double nodeZ = node->Z();
-// 	      MESSAGE("NODE -> ID = " << nodeId << " X = " << nodeX << " Y = " << nodeY << " Z = " << nodeZ);
-	      listNodeCoresNetgenSmesh[indexNodes] = nodeId;
-	      int index = indexNodes*spaceDimension;
-	      Netgen_Coordinates[index] = nodeX;
-	      Netgen_Coordinates[index+1] = nodeY;
-	      Netgen_Coordinates[index+2] = nodeZ;
-	      netgenToDS[indexNodes] = node;
-	      indexNodes++;
-	    }
-	}
-
-      for (int i=0; i<Netgen_NbOfNodes; i++)
-	{
-	  ASSERT(listNodeCoresNetgenSmesh[i] != 0);
-
-	  for (int j=0; j<Netgen_NbOfNodes && j!=i; j++)
-	    ASSERT(listNodeCoresNetgenSmesh[i] != listNodeCoresNetgenSmesh[j]);
-
-	  for (int j=0; j<spaceDimension; j++)
-	    ASSERT(Netgen_Coordinates[i*spaceDimension+j] != bigNumber);
-	}
-
-      int indexTrias = 0;
-      for (int i=0; i<numberOfFaces; i++)
-	{
-	  const SMESHDS_SubMesh * aSubMeshDSFace =
-	    meshFaces[i]->GetSubMeshDS();
-
-	  TopoDS_Shape aFace = shapeFaces[i];
-
-	  SMDS_ElemIteratorPtr iteratorTriangle = aSubMeshDSFace->GetElements();
-
-	  TopoDS_Shape aShapeFace = meshFaces[i]->GetSubShape();
-
-	  bool orientationMeshFace = (aFace.Orientation() == aShapeFace.Orientation());
-
-	  if (orientationMeshFace)
-	    {
-	      while(iteratorTriangle->more())
-		{
-		  const SMDS_MeshElement * triangle = iteratorTriangle->next();
-
-		  SMDS_ElemIteratorPtr triangleNodesIt = triangle->nodesIterator();
-
-		  int triangleNode1 = (triangleNodesIt->next())->GetID();
-		  int triangleNode2 = (triangleNodesIt->next())->GetID();
-		  int triangleNode3 = (triangleNodesIt->next())->GetID();
-
-		  int N1New = 0;
-		  int N2New = 0;
-		  int N3New = 0;
-		  int index = indexTrias*nbNodesByTri;
-
-		  for (int j=0; j<Netgen_NbOfNodes; j++)
-		    {
-		      int jp1 = j+1;
-
-		      if (triangleNode1 == listNodeCoresNetgenSmesh[j])
-			N1New = jp1;
-		      else if (triangleNode2 == listNodeCoresNetgenSmesh[j])
-			N2New = jp1;
-		      else if (triangleNode3 == listNodeCoresNetgenSmesh[j])
-			N3New = jp1;
-		    }
-
-		  triangleNode1 = N1New;
-		  triangleNode2 = N2New;
-		  triangleNode3 = N3New;
-
-		  Netgen_Connectivity[index] = triangleNode1;
-		  Netgen_Connectivity[index+1] = triangleNode2;
-		  Netgen_Connectivity[index+2] = triangleNode3;
-
-		  indexTrias++;
-		}
-	    }
-	  else
-	    {
-	      while(iteratorTriangle->more())
-		{
-		  const SMDS_MeshElement * triangle = iteratorTriangle->next();
-
-		  SMDS_ElemIteratorPtr triangleNodesIt = triangle->nodesIterator();
-
-		  int triangleNode1 = (triangleNodesIt->next())->GetID();
-		  int triangleNode3 = (triangleNodesIt->next())->GetID();
-		  int triangleNode2 = (triangleNodesIt->next())->GetID();
-
-		  int N1New = 0;
-		  int N2New = 0;
-		  int N3New = 0;
-		  int index = indexTrias*nbNodesByTri;
-
-		  for (int j=0; j<Netgen_NbOfNodes; j++)
-		    {
-		      int jp1 = j+1;
-
-		      if (triangleNode1 == listNodeCoresNetgenSmesh[j])
-			N1New = jp1;
-		      else if (triangleNode2 == listNodeCoresNetgenSmesh[j])
-			N2New = jp1;
-		      else if (triangleNode3 == listNodeCoresNetgenSmesh[j])
-			N3New = jp1;
-		    }
-
-		  triangleNode1 = N1New;
-		  triangleNode2 = N2New;
-		  triangleNode3 = N3New;
-
-		  Netgen_Connectivity[index] = triangleNode1;
-		  Netgen_Connectivity[index+1] = triangleNode2;
-		  Netgen_Connectivity[index+2] = triangleNode3;
-
-		  indexTrias++;
-		}
-	    }
-	}
-
-      int * nodesUsed = new int[Netgen_NbOfNodes];
-
-      for (int i=0; i<Netgen_NbOfNodes; i++) nodesUsed[i] = 0;
-
-      for (int i=0; i<Netgen_NbOfTria; i++)
-	for (int j=0; j<nbNodesByTri; j++)
-	  {
-	    int Nij = Netgen_Connectivity[i*nbNodesByTri+j];
-
-	    ASSERT((Nij>=1) && (Nij<=Netgen_NbOfNodes));
-
-	    nodesUsed[Nij-1] = 1;
-	    Netgen_Connectivity[i*nbNodesByTri+j] = Nij;
-	  }
-
-      for (int i=0; i<Netgen_NbOfNodes; i++)
-	{
-	  ASSERT(nodesUsed[i] != 0);
-	}
-
-      delete [] nodesUsed;
-
-      /*
-	Feed the Netgen surface mesh
-      */
-      Ng_Mesh * Netgen_mesh;
-
-      Ng_Init();
-
-      Netgen_mesh = Ng_NewMesh();
-
-      Ng_Meshing_Parameters Netgen_param;
-
-      for (int i=0; i<Netgen_NbOfNodes; i++)
-	{
-	  for (int j=0; j<spaceDimension; j++)
-	    Netgen_point[j] = Netgen_Coordinates[i*spaceDimension+j];
-
-	  Ng_AddPoint(Netgen_mesh, Netgen_point);
-	}
-
-      for (int i=0; i<Netgen_NbOfTria; i++)
-	{
-	  for (int j=0; j<nbNodesByTri; j++)
-	    Netgen_triangle[j] = Netgen_Connectivity[i*nbNodesByTri+j];
-
-	  Ng_AddSurfaceElement(Netgen_mesh, NG_TRIG, Netgen_triangle);
-	}
-
-      Netgen_param.secondorder = Netgen_param2ndOrder;
-      Netgen_param.fineness = Netgen_paramFine;
-      Netgen_param.maxh = Netgen_paramSize;
-
-      /*
-	Generate the volume mesh
-      */
-
-      ASSERT(Netgen_NbOfNodes == Ng_GetNP(Netgen_mesh));
-      ASSERT(Ng_GetNE(Netgen_mesh) == 0);
-      ASSERT(Netgen_NbOfTria == Ng_GetNSE(Netgen_mesh));
-
-      Ng_Result status;
-
-      try {
-        status = Ng_GenerateVolumeMesh(Netgen_mesh, &Netgen_param);
-      } catch (...) {
-        MESSAGE("An exception has been caught during the Volume Mesh Generation ...");
-        status = NG_VOLUME_FAILURE;
-      }
-
-      int Netgen_NbOfNodesNew = Ng_GetNP(Netgen_mesh);
-
-      int Netgen_NbOfTetra = Ng_GetNE(Netgen_mesh);
-
-      MESSAGE("End of Volume Mesh Generation. status=" << status <<
-              ", nb new nodes: " << Netgen_NbOfNodesNew - Netgen_NbOfNodes <<
-              ", nb tetra: " << Netgen_NbOfTetra);
-
-      if ((status != NG_OK) ||
-	  (Netgen_NbOfTetra <= 0))
-	{
-	  /*
-	    Free the memory needed by to generate the Netgen Mesh
-	  */
-
-	  delete [] Netgen_Coordinates;
-	  delete [] Netgen_Connectivity;
-	  delete [] Netgen_point;
-	  delete [] Netgen_triangle;
-	  delete [] Netgen_tetrahedron;
-
-	  delete [] listNodeCoresNetgenSmesh;
-
-	  Ng_DeleteMesh(Netgen_mesh);
-	  Ng_Exit();
-
-	  return false;
-	}
-
-
-      double * Netgen_CoordinatesNew = new double [spaceDimension*Netgen_NbOfNodesNew];
-      int * Netgen_ConnectivityNew = new int [nbNodesByTetra*Netgen_NbOfTetra];
-
-      for (int i=0; i<Netgen_NbOfNodesNew; i++)
-	{
-	  Ng_GetPoint(Netgen_mesh, (i+1), Netgen_point);
-
-	  for (int j=0; j<spaceDimension; j++)
-	    Netgen_CoordinatesNew[i*spaceDimension+j] = Netgen_point[j];
-	}
-
-      for (int i=0; i<Netgen_NbOfNodes; i++)
-	for (int j=0; j<spaceDimension; j++)
-	  ASSERT(Netgen_CoordinatesNew[i*spaceDimension+j] == Netgen_Coordinates[i*spaceDimension+j])
-
-      for (int i=0; i<Netgen_NbOfTetra; i++)
-	{
-	  Ng_GetVolumeElement(Netgen_mesh, (i+1), Netgen_tetrahedron);
-
-	  for (int j=0; j<nbNodesByTetra; j++)
-	    Netgen_ConnectivityNew[i*nbNodesByTetra+j] = Netgen_tetrahedron[j];
-	}
-
-      /*
-	Feed back the SMESHDS with the generated Nodes and Volume Elements
-      */
-
-      int NbTotOfNodesShell = Netgen_NbOfNodesNew - Netgen_NbOfNodes;
-
-      int * listNodeShellCoresNetgenSmesh = new int [NbTotOfNodesShell];
-
-      for (int i=0; i<NbTotOfNodesShell; i++)
-	listNodeShellCoresNetgenSmesh[i] = 0;
-
-      for (int i=0; i<NbTotOfNodesShell; i++)
-	{
-	  int index = (i+Netgen_NbOfNodes)*spaceDimension;
-
-	  SMDS_MeshNode * node =
-	    meshDS->AddNode(Netgen_CoordinatesNew[index],
-			    Netgen_CoordinatesNew[index+1],
-			    Netgen_CoordinatesNew[index+2]);
-
-	  meshDS->SetNodeInVolume(node, aShell);
-
-	  index = i+Netgen_NbOfNodes;
-	  netgenToDS[index] = node;
-
-	  listNodeShellCoresNetgenSmesh[i] = node->GetID();
-	}
-
-      for (int i=0; i<NbTotOfNodesShell; i++)
-	{
-	  ASSERT(listNodeShellCoresNetgenSmesh[i] != 0);
-
-	  for (int j=0; j<NbTotOfNodesShell && j!=i; j++)
-	    ASSERT(listNodeShellCoresNetgenSmesh[i] != listNodeShellCoresNetgenSmesh[j]);
-	}
-
-      for (int i=0; i<Netgen_NbOfTetra; i++)
-	{
-	  int index = i*nbNodesByTetra;
-	  int tetraNode1 = Netgen_ConnectivityNew[index];
-	  int tetraNode2 = Netgen_ConnectivityNew[index+1];
-	  int tetraNode3 = Netgen_ConnectivityNew[index+2];
-	  int tetraNode4 = Netgen_ConnectivityNew[index+3];
-
-	  const SMDS_MeshNode * node1 = netgenToDS[tetraNode1-1];
-	  const SMDS_MeshNode * node2 = netgenToDS[tetraNode2-1];
-	  const SMDS_MeshNode * node3 = netgenToDS[tetraNode3-1];
-	  const SMDS_MeshNode * node4 = netgenToDS[tetraNode4-1];
-
-	  index = tetraNode1;
-	  if (index <= Netgen_NbOfNodes)
-	    tetraNode1 = listNodeCoresNetgenSmesh[index-1];
-	  else
-	    tetraNode1 = listNodeShellCoresNetgenSmesh[index-Netgen_NbOfNodes-1];
-
-	  index = tetraNode2;
-	  if (index <= Netgen_NbOfNodes)
-	    tetraNode2 = listNodeCoresNetgenSmesh[index-1];
-	  else
-	    tetraNode2 = listNodeShellCoresNetgenSmesh[index-Netgen_NbOfNodes-1];
-
-	  index = tetraNode3;
-	  if (index <= Netgen_NbOfNodes)
-	    tetraNode3 = listNodeCoresNetgenSmesh[index-1];
-	  else
-	    tetraNode3 = listNodeShellCoresNetgenSmesh[index-Netgen_NbOfNodes-1];
-
-	  index = tetraNode4;
-	  if (index <= Netgen_NbOfNodes)
-	    tetraNode4 = listNodeCoresNetgenSmesh[index-1];
-	  else
-	    tetraNode4 = listNodeShellCoresNetgenSmesh[index-Netgen_NbOfNodes-1];
-
-	  SMDS_MeshVolume * elt =
-	    meshDS->AddVolume(node1,node2,node3,node4);
-
-	  meshDS->SetMeshElementOnShape(elt, aShell);
-	}
-
-      /*
-	Free the memory needed by to generate the Netgen Mesh
-      */
-
-      delete [] Netgen_Coordinates;
-      delete [] Netgen_Connectivity;
-      delete [] Netgen_CoordinatesNew;
-      delete [] Netgen_ConnectivityNew;
-      delete [] Netgen_point;
-      delete [] Netgen_triangle;
-      delete [] Netgen_tetrahedron;
-
-      delete [] listNodeCoresNetgenSmesh;
-      delete [] listNodeShellCoresNetgenSmesh;
-
-      Ng_DeleteMesh(Netgen_mesh);
-      Ng_Exit();
-
-      return true;
+      Ng_GetVolumeElement(Netgen_mesh, elemIndex, Netgen_tetrahedron);
+      SMDS_MeshVolume * elt = meshDS->AddVolume (nodeVec[ Netgen_tetrahedron[0] ],
+                                                 nodeVec[ Netgen_tetrahedron[1] ],
+                                                 nodeVec[ Netgen_tetrahedron[2] ],
+                                                 nodeVec[ Netgen_tetrahedron[3] ]);
+      meshDS->SetMeshElementOnShape(elt, aShell);
     }
+  }
 
-  return false;
-}
+  Ng_DeleteMesh(Netgen_mesh);
+  Ng_Exit();
 
+  return isOK;
+}
 
 //=============================================================================
 /*!
-- 
2.39.2