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GPUSPHGUI: add Offset transformation
[modules/smesh.git] / src / SMESH / SMESH_MeshEditor.cxx
index cfe4c3e8669478173a7ab6c3629688ac6f5843f3..b86d7f5e0d270e71075857179eb6294365413b65 100644 (file)
@@ -46,8 +46,6 @@
 #include "SMESH_OctreeNode.hxx"
 #include "SMESH_subMesh.hxx"
 
-#include <Basics_OCCTVersion.hxx>
-
 #include "utilities.h"
 #include "chrono.hxx"
 
 #include <sstream>
 
 #include <boost/tuple/tuple.hpp>
+#include <boost/container/flat_set.hpp>
 
 #include <Standard_Failure.hxx>
 #include <Standard_ErrorHandler.hxx>
+#include <OSD_Parallel.hxx>
+
+#include "SMESH_TryCatch.hxx" // include after OCCT headers!
 
 #define cast2Node(elem) static_cast<const SMDS_MeshNode*>( elem )
 
 using namespace std;
 using namespace SMESH::Controls;
 
-namespace
-{
-  template < class ELEM_SET >
-  SMDS_ElemIteratorPtr elemSetIterator( const ELEM_SET& elements )
-  {
-    typedef SMDS_SetIterator
-      < SMDS_pElement, typename ELEM_SET::const_iterator> TSetIterator;
-    return SMDS_ElemIteratorPtr( new TSetIterator( elements.begin(), elements.end() ));
-  }
-}
-
 //=======================================================================
 //function : SMESH_MeshEditor
 //purpose  :
@@ -145,8 +136,8 @@ SMESHDS_Mesh * SMESH_MeshEditor::GetMeshDS()
 
 void SMESH_MeshEditor::ClearLastCreated()
 {
-  myLastCreatedNodes.Clear();
-  myLastCreatedElems.Clear();
+  SMESHUtils::FreeVector( myLastCreatedElems );
+  SMESHUtils::FreeVector( myLastCreatedNodes );
 }
 
 //================================================================================
@@ -378,7 +369,7 @@ SMESH_MeshEditor::AddElement(const vector<const SMDS_MeshNode*> & node,
 
   default:;
   }
-  if ( e ) myLastCreatedElems.Append( e );
+  if ( e ) myLastCreatedElems.push_back( e );
   return e;
 }
 
@@ -412,8 +403,7 @@ SMDS_MeshElement* SMESH_MeshEditor::AddElement(const vector<int> & nodeIDs,
 int SMESH_MeshEditor::Remove (const list< int >& theIDs,
                               const bool         isNodes )
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   SMESHDS_Mesh* aMesh = GetMeshDS();
   set< SMESH_subMesh *> smmap;
@@ -493,7 +483,7 @@ void SMESH_MeshEditor::Create0DElementsOnAllNodes( const TIDSortedElemSet& eleme
   }
   else
   {
-    elemIt = elemSetIterator( elements );
+    elemIt = SMESHUtils::elemSetIterator( elements );
   }
 
   while ( elemIt->more() )
@@ -506,8 +496,8 @@ void SMESH_MeshEditor::Create0DElementsOnAllNodes( const TIDSortedElemSet& eleme
       SMDS_ElemIteratorPtr it0D = n->GetInverseElementIterator( SMDSAbs_0DElement );
       if ( duplicateElements || !it0D->more() )
       {
-        myLastCreatedElems.Append( GetMeshDS()->Add0DElement( n ));
-        all0DElems.insert( myLastCreatedElems.Last() );
+        myLastCreatedElems.push_back( GetMeshDS()->Add0DElement( n ));
+        all0DElems.insert( myLastCreatedElems.back() );
       }
       while ( it0D->more() )
         all0DElems.insert( it0D->next() );
@@ -523,8 +513,7 @@ void SMESH_MeshEditor::Create0DElementsOnAllNodes( const TIDSortedElemSet& eleme
 
 int SMESH_MeshEditor::FindShape (const SMDS_MeshElement * theElem)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   SMESHDS_Mesh * aMesh = GetMeshDS();
   if ( aMesh->ShapeToMesh().IsNull() )
@@ -691,8 +680,7 @@ static bool getNodesFromTwoTria(const SMDS_MeshElement * theTria1,
 bool SMESH_MeshEditor::InverseDiag (const SMDS_MeshElement * theTria1,
                                     const SMDS_MeshElement * theTria2 )
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if (!theTria1 || !theTria2)
     return false;
@@ -892,8 +880,7 @@ static bool findTriangles(const SMDS_MeshNode *    theNode1,
 bool SMESH_MeshEditor::InverseDiag (const SMDS_MeshNode * theNode1,
                                     const SMDS_MeshNode * theNode2)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   const SMDS_MeshElement *tr1, *tr2;
   if ( !findTriangles( theNode1, theNode2, tr1, tr2 ))
@@ -1013,8 +1000,7 @@ bool getQuadrangleNodes(const SMDS_MeshNode *    theQuadNodes [],
 bool SMESH_MeshEditor::DeleteDiag (const SMDS_MeshNode * theNode1,
                                    const SMDS_MeshNode * theNode2)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   const SMDS_MeshElement *tr1, *tr2;
   if ( !findTriangles( theNode1, theNode2, tr1, tr2 ))
@@ -1035,13 +1021,13 @@ bool SMESH_MeshEditor::DeleteDiag (const SMDS_MeshNode * theNode1,
 
     const SMDS_MeshElement* newElem = 0;
     newElem = aMesh->AddFace( aNodes[0], aNodes[1], aNodes[2], aNodes[3] );
-    myLastCreatedElems.Append(newElem);
+    myLastCreatedElems.push_back(newElem);
     AddToSameGroups( newElem, tr1, aMesh );
     int aShapeId = tr1->getshapeId();
     if ( aShapeId )
-      {
-        aMesh->SetMeshElementOnShape( newElem, aShapeId );
-      }
+    {
+      aMesh->SetMeshElementOnShape( newElem, aShapeId );
+    }
     aMesh->RemoveElement( tr1 );
     aMesh->RemoveElement( tr2 );
 
@@ -1085,13 +1071,13 @@ bool SMESH_MeshEditor::DeleteDiag (const SMDS_MeshNode * theNode1,
   const SMDS_MeshElement* newElem = 0;
   newElem = aMesh->AddFace( aNodes[0], aNodes[1], aNodes[2], aNodes[3],
                             aNodes[4], aNodes[5], aNodes[6], aNodes[7]);
-  myLastCreatedElems.Append(newElem);
+  myLastCreatedElems.push_back(newElem);
   AddToSameGroups( newElem, tr1, aMesh );
   int aShapeId = tr1->getshapeId();
   if ( aShapeId )
-    {
-      aMesh->SetMeshElementOnShape( newElem, aShapeId );
-    }
+  {
+    aMesh->SetMeshElementOnShape( newElem, aShapeId );
+  }
   aMesh->RemoveElement( tr1 );
   aMesh->RemoveElement( tr2 );
 
@@ -1108,8 +1094,7 @@ bool SMESH_MeshEditor::DeleteDiag (const SMDS_MeshNode * theNode1,
 
 bool SMESH_MeshEditor::Reorient (const SMDS_MeshElement * theElem)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if (!theElem)
     return false;
@@ -1278,7 +1263,7 @@ int SMESH_MeshEditor::Reorient2D (TIDSortedElemSet &       theFaces,
         }
         if ( otherFace && otherFace != theFace)
         {
-          // link must be reverse in otherFace if orientation ot otherFace
+          // link must be reverse in otherFace if orientation to otherFace
           // is same as that of theFace
           if ( abs(nodeInd2-nodeInd1) == 1 ? nodeInd2 > nodeInd1 : nodeInd1 > nodeInd2 )
           {
@@ -1314,7 +1299,7 @@ int SMESH_MeshEditor::Reorient2DBy3D (TIDSortedElemSet & theFaces,
   if ( theFaces.empty() )
     faceIt = GetMeshDS()->elementsIterator( SMDSAbs_Face );
   else
-    faceIt = elemSetIterator( theFaces );
+    faceIt = SMESHUtils::elemSetIterator( theFaces );
 
   vector< const SMDS_MeshNode* > faceNodes;
   TIDSortedElemSet checkedVolumes;
@@ -1403,17 +1388,17 @@ static double getBadRate (const SMDS_MeshElement*               theElem,
 bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet &                   theElems,
                                   SMESH::Controls::NumericalFunctorPtr theCrit)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( !theCrit.get() )
     return false;
 
-  SMESHDS_Mesh * aMesh = GetMeshDS();
-
+  SMESHDS_Mesh *       aMesh = GetMeshDS();
   Handle(Geom_Surface) surface;
   SMESH_MesherHelper   helper( *GetMesh() );
 
+  myLastCreatedElems.reserve( theElems.size() * 2 );
+
   TIDSortedElemSet::iterator itElem;
   for ( itElem = theElems.begin(); itElem != theElems.end(); itElem++ )
   {
@@ -1482,8 +1467,8 @@ bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet &                   theElems,
 
     // care of a new element
 
-    myLastCreatedElems.Append(newElem1);
-    myLastCreatedElems.Append(newElem2);
+    myLastCreatedElems.push_back(newElem1);
+    myLastCreatedElems.push_back(newElem2);
     AddToSameGroups( newElem1, elem, aMesh );
     AddToSameGroups( newElem2, elem, aMesh );
 
@@ -1500,21 +1485,21 @@ bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet &                   theElems,
 //=======================================================================
 /*!
  * \brief Split each of given quadrangles into 4 triangles.
- * \param theElems - The faces to be splitted. If empty all faces are split.
+ * \param theElems - The faces to be split. If empty all faces are split.
  */
 //=======================================================================
 
 void SMESH_MeshEditor::QuadTo4Tri (TIDSortedElemSet & theElems)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
+  myLastCreatedElems.reserve( theElems.size() * 4 );
 
   SMESH_MesherHelper helper( *GetMesh() );
   helper.SetElementsOnShape( true );
 
   SMDS_ElemIteratorPtr faceIt;
   if ( theElems.empty() ) faceIt = GetMeshDS()->elementsIterator(SMDSAbs_Face);
-  else                    faceIt = elemSetIterator( theElems );
+  else                    faceIt = SMESHUtils::elemSetIterator( theElems );
 
   bool   checkUV;
   gp_XY  uv [9]; uv[8] = gp_XY(0,0);
@@ -1598,7 +1583,7 @@ void SMESH_MeshEditor::QuadTo4Tri (TIDSortedElemSet & theElems)
 
       nCentral = helper.AddNode( xyz[8].X(), xyz[8].Y(), xyz[8].Z(), /*id=*/0,
                                  uv[8].X(), uv[8].Y() );
-      myLastCreatedNodes.Append( nCentral );
+      myLastCreatedNodes.push_back( nCentral );
     }
 
     // create 4 triangles
@@ -1616,7 +1601,7 @@ void SMESH_MeshEditor::QuadTo4Tri (TIDSortedElemSet & theElems)
                                                nodes[(i+1)%4],
                                                nCentral );
       ReplaceElemInGroups( tria, quad, GetMeshDS() );
-      myLastCreatedElems.Append( tria );
+      myLastCreatedElems.push_back( tria );
     }
   }
 }
@@ -1629,8 +1614,7 @@ void SMESH_MeshEditor::QuadTo4Tri (TIDSortedElemSet & theElems)
 int SMESH_MeshEditor::BestSplit (const SMDS_MeshElement*              theQuad,
                                  SMESH::Controls::NumericalFunctorPtr theCrit)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if (!theCrit.get())
     return -1;
@@ -2297,7 +2281,7 @@ void SMESH_MeshEditor::SplitVolumes (const TFacetOfElem & theElems,
       volTool.GetBaryCenter( bc[0], bc[1], bc[2] );
       SMDS_MeshNode* gcNode = helper.AddNode( bc[0], bc[1], bc[2] );
       nodes.push_back( gcNode );
-      newNodes.Append( gcNode );
+      newNodes.push_back( gcNode );
     }
     if ( !splitMethod._faceBaryNode.empty() )
     {
@@ -2311,7 +2295,7 @@ void SMESH_MeshEditor::SplitVolumes (const TFacetOfElem & theElems,
         if ( !f_n->second )
         {
           volTool.GetFaceBaryCenter( iF_n->first, bc[0], bc[1], bc[2] );
-          newNodes.Append( f_n->second = helper.AddNode( bc[0], bc[1], bc[2] ));
+          newNodes.push_back( f_n->second = helper.AddNode( bc[0], bc[1], bc[2] ));
         }
         nodes.push_back( iF_n->second = f_n->second );
       }
@@ -2322,18 +2306,18 @@ void SMESH_MeshEditor::SplitVolumes (const TFacetOfElem & theElems,
     const int* volConn = splitMethod._connectivity;
     if ( splitMethod._nbCorners == 4 ) // tetra
       for ( int i = 0; i < splitMethod._nbSplits; ++i, volConn += splitMethod._nbCorners )
-        newElems.Append( splitVols[ i ] = helper.AddVolume( nodes[ volConn[0] ],
-                                                            nodes[ volConn[1] ],
-                                                            nodes[ volConn[2] ],
-                                                            nodes[ volConn[3] ]));
+        newElems.push_back( splitVols[ i ] = helper.AddVolume( nodes[ volConn[0] ],
+                                                               nodes[ volConn[1] ],
+                                                               nodes[ volConn[2] ],
+                                                               nodes[ volConn[3] ]));
     else // prisms
       for ( int i = 0; i < splitMethod._nbSplits; ++i, volConn += splitMethod._nbCorners )
-        newElems.Append( splitVols[ i ] = helper.AddVolume( nodes[ volConn[0] ],
-                                                            nodes[ volConn[1] ],
-                                                            nodes[ volConn[2] ],
-                                                            nodes[ volConn[3] ],
-                                                            nodes[ volConn[4] ],
-                                                            nodes[ volConn[5] ]));
+        newElems.push_back( splitVols[ i ] = helper.AddVolume( nodes[ volConn[0] ],
+                                                               nodes[ volConn[1] ],
+                                                               nodes[ volConn[2] ],
+                                                               nodes[ volConn[3] ],
+                                                               nodes[ volConn[4] ],
+                                                               nodes[ volConn[5] ]));
 
     ReplaceElemInGroups( elem, splitVols, GetMeshDS() );
 
@@ -2386,7 +2370,7 @@ void SMESH_MeshEditor::SplitVolumes (const TFacetOfElem & theElems,
               gp_XY uv( 1e100, 1e100 );
               double distXYZ[4];
               if ( !fHelper.CheckNodeUV( TopoDS::Face( s ), baryNode,
-                                        uv, /*tol=*/1e-7, /*force=*/true, distXYZ ) &&
+                                         uv, /*tol=*/1e-7, /*force=*/true, distXYZ ) &&
                    uv.X() < 1e100 )
               {
                 // node is too far from the surface
@@ -2440,7 +2424,7 @@ void SMESH_MeshEditor::SplitVolumes (const TFacetOfElem & theElems,
           if ( !triangles[ i ]) continue;
           if ( fSubMesh )
             fSubMesh->AddElement( triangles[ i ]);
-          newElems.Append( triangles[ i ]);
+          newElems.push_back( triangles[ i ]);
         }
         ReplaceElemInGroups( face, triangles, GetMeshDS() );
         GetMeshDS()->RemoveFreeElement( face, fSubMesh, /*fromGroups=*/false );
@@ -2477,7 +2461,7 @@ void SMESH_MeshEditor::GetHexaFacetsToSplit( TIDSortedElemSet& theHexas,
                                              const gp_Ax1&     theFacetNormal,
                                              TFacetOfElem &    theFacets)
 {
-  #define THIS_METHOD "SMESH_MeshEditor::GetHexaFacetsToSplit(): "
+#define THIS_METHOD "SMESH_MeshEditor::GetHexaFacetsToSplit(): "
 
   // Find a hexa closest to the location of theFacetNormal
 
@@ -2931,11 +2915,10 @@ void SMESH_MeshEditor::ReplaceElemInGroups (const SMDS_MeshElement*
 bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet & theElems,
                                   const bool         the13Diag)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
-
-  SMESHDS_Mesh * aMesh = GetMeshDS();
+  ClearLastCreated();
+  myLastCreatedElems.reserve( theElems.size() * 2 );
 
+  SMESHDS_Mesh *       aMesh = GetMeshDS();
   Handle(Geom_Surface) surface;
   SMESH_MesherHelper   helper( *GetMesh() );
 
@@ -2965,8 +2948,8 @@ bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet & theElems,
         newElem1 = aMesh->AddFace( aNodes[3], aNodes[0], aNodes[1] );
         newElem2 = aMesh->AddFace( aNodes[3], aNodes[1], aNodes[2] );
       }
-      myLastCreatedElems.Append(newElem1);
-      myLastCreatedElems.Append(newElem2);
+      myLastCreatedElems.push_back(newElem1);
+      myLastCreatedElems.push_back(newElem2);
       // put a new triangle on the same shape and add to the same groups
       if ( aShapeId )
       {
@@ -3008,7 +2991,7 @@ bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet & theElems,
         centrNode = helper.GetCentralNode( aNodes[0], aNodes[1], aNodes[2], aNodes[3],
                                            aNodes[4], aNodes[5], aNodes[6], aNodes[7],
                                            surface.IsNull() );
-        myLastCreatedNodes.Append(centrNode);
+        myLastCreatedNodes.push_back(centrNode);
       }
 
       // create a new element
@@ -3026,8 +3009,8 @@ bool SMESH_MeshEditor::QuadToTri (TIDSortedElemSet & theElems,
         newElem2 = aMesh->AddFace(aNodes[3], aNodes[1], aNodes[2],
                                   centrNode, aNodes[5], aNodes[6] );
       }
-      myLastCreatedElems.Append(newElem1);
-      myLastCreatedElems.Append(newElem2);
+      myLastCreatedElems.push_back(newElem1);
+      myLastCreatedElems.push_back(newElem2);
       // put a new triangle on the same shape and add to the same groups
       if ( aShapeId )
       {
@@ -3151,8 +3134,8 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
                                   SMESH::Controls::NumericalFunctorPtr theCrit,
                                   const double                         theMaxAngle)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
+  myLastCreatedElems.reserve( theElems.size() / 2 );
 
   if ( !theCrit.get() )
     return false;
@@ -3336,7 +3319,7 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
           {
             const SMDS_MeshElement* newElem = 0;
             newElem = aMesh->AddFace(n12[0], n12[1], n12[2], n12[3] );
-            myLastCreatedElems.Append(newElem);
+            myLastCreatedElems.push_back(newElem);
             AddToSameGroups( newElem, tr1, aMesh );
             int aShapeId = tr1->getshapeId();
             if ( aShapeId )
@@ -3367,7 +3350,7 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
             else
               newElem = aMesh->AddFace(aNodes[0], aNodes[1], aNodes[2], aNodes[3],
                                        aNodes[4], aNodes[5], aNodes[6], aNodes[7]);
-            myLastCreatedElems.Append(newElem);
+            myLastCreatedElems.push_back(newElem);
             AddToSameGroups( newElem, tr1, aMesh );
             int aShapeId = tr1->getshapeId();
             if ( aShapeId )
@@ -3390,7 +3373,7 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
           if ( tr1->NbNodes() == 3 ) {
             const SMDS_MeshElement* newElem = 0;
             newElem = aMesh->AddFace(n13[0], n13[1], n13[2], n13[3] );
-            myLastCreatedElems.Append(newElem);
+            myLastCreatedElems.push_back(newElem);
             AddToSameGroups( newElem, tr1, aMesh );
             int aShapeId = tr1->getshapeId();
             if ( aShapeId )
@@ -3421,7 +3404,7 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
             else
               newElem = aMesh->AddFace(aNodes[0], aNodes[1], aNodes[2], aNodes[3],
                                        aNodes[4], aNodes[5], aNodes[6], aNodes[7]);
-            myLastCreatedElems.Append(newElem);
+            myLastCreatedElems.push_back(newElem);
             AddToSameGroups( newElem, tr1, aMesh );
             int aShapeId = tr1->getshapeId();
             if ( aShapeId )
@@ -3449,286 +3432,6 @@ bool SMESH_MeshEditor::TriToQuad (TIDSortedElemSet &                   theElems,
   return true;
 }
 
-
-/*#define DUMPSO(txt) \
-//  cout << txt << endl;
-//=============================================================================
-//
-//
-//
-//=============================================================================
-static void swap( int i1, int i2, int idNodes[], gp_Pnt P[] )
-{
-if ( i1 == i2 )
-return;
-int tmp = idNodes[ i1 ];
-idNodes[ i1 ] = idNodes[ i2 ];
-idNodes[ i2 ] = tmp;
-gp_Pnt Ptmp = P[ i1 ];
-P[ i1 ] = P[ i2 ];
-P[ i2 ] = Ptmp;
-DUMPSO( i1 << "(" << idNodes[ i2 ] << ") <-> " << i2 << "(" << idNodes[ i1 ] << ")");
-}
-
-//=======================================================================
-//function : SortQuadNodes
-//purpose  : Set 4 nodes of a quadrangle face in a good order.
-//           Swap 1<->2 or 2<->3 nodes and correspondingly return
-//           1 or 2 else 0.
-//=======================================================================
-
-int SMESH_MeshEditor::SortQuadNodes (const SMDS_Mesh * theMesh,
-int               idNodes[] )
-{
-  gp_Pnt P[4];
-  int i;
-  for ( i = 0; i < 4; i++ ) {
-    const SMDS_MeshNode *n = theMesh->FindNode( idNodes[i] );
-    if ( !n ) return 0;
-    P[ i ].SetCoord( n->X(), n->Y(), n->Z() );
-  }
-
-  gp_Vec V1(P[0], P[1]);
-  gp_Vec V2(P[0], P[2]);
-  gp_Vec V3(P[0], P[3]);
-
-  gp_Vec Cross1 = V1 ^ V2;
-  gp_Vec Cross2 = V2 ^ V3;
-
-  i = 0;
-  if (Cross1.Dot(Cross2) < 0)
-  {
-    Cross1 = V2 ^ V1;
-    Cross2 = V1 ^ V3;
-
-    if (Cross1.Dot(Cross2) < 0)
-      i = 2;
-    else
-      i = 1;
-    swap ( i, i + 1, idNodes, P );
-
-    //     for ( int ii = 0; ii < 4; ii++ ) {
-    //       const SMDS_MeshNode *n = theMesh->FindNode( idNodes[ii] );
-    //       DUMPSO( ii << "(" << idNodes[ii] <<") : "<<n->X()<<" "<<n->Y()<<" "<<n->Z());
-    //     }
-  }
-  return i;
-}
-
-//=======================================================================
-//function : SortHexaNodes
-//purpose  : Set 8 nodes of a hexahedron in a good order.
-//           Return success status
-//=======================================================================
-
-bool SMESH_MeshEditor::SortHexaNodes (const SMDS_Mesh * theMesh,
-                                      int               idNodes[] )
-{
-  gp_Pnt P[8];
-  int i;
-  DUMPSO( "INPUT: ========================================");
-  for ( i = 0; i < 8; i++ ) {
-    const SMDS_MeshNode *n = theMesh->FindNode( idNodes[i] );
-    if ( !n ) return false;
-    P[ i ].SetCoord( n->X(), n->Y(), n->Z() );
-    DUMPSO( i << "(" << idNodes[i] <<") : "<<n->X()<<" "<<n->Y()<<" "<<n->Z());
-  }
-  DUMPSO( "========================================");
-
-
-  set<int> faceNodes;  // ids of bottom face nodes, to be found
-  set<int> checkedId1; // ids of tried 2-nd nodes
-  Standard_Real leastDist = DBL_MAX; // dist of the 4-th node from 123 plane
-  const Standard_Real tol = 1.e-6;   // tolerance to find nodes in plane
-  int iMin, iLoop1 = 0;
-
-  // Loop to try the 2-nd nodes
-
-  while ( leastDist > DBL_MIN && ++iLoop1 < 8 )
-  {
-    // Find not checked 2-nd node
-    for ( i = 1; i < 8; i++ )
-      if ( checkedId1.find( idNodes[i] ) == checkedId1.end() ) {
-        int id1 = idNodes[i];
-        swap ( 1, i, idNodes, P );
-        checkedId1.insert ( id1 );
-        break;
-      }
-
-    // Find the 3-d node so that 1-2-3 triangle to be on a hexa face,
-    // ie that all but meybe one (id3 which is on the same face) nodes
-    // lay on the same side from the triangle plane.
-
-    bool manyInPlane = false; // more than 4 nodes lay in plane
-    int iLoop2 = 0;
-    while ( ++iLoop2 < 6 ) {
-
-      // get 1-2-3 plane coeffs
-      Standard_Real A, B, C, D;
-      gp_Vec N = gp_Vec (P[0], P[1]).Crossed( gp_Vec (P[0], P[2]) );
-      if ( N.SquareMagnitude() > gp::Resolution() )
-      {
-        gp_Pln pln ( P[0], N );
-        pln.Coefficients( A, B, C, D );
-
-        // find the node (iMin) closest to pln
-        Standard_Real dist[ 8 ], minDist = DBL_MAX;
-        set<int> idInPln;
-        for ( i = 3; i < 8; i++ ) {
-          dist[i] = A * P[i].X() + B * P[i].Y() + C * P[i].Z() + D;
-          if ( fabs( dist[i] ) < minDist ) {
-            minDist = fabs( dist[i] );
-            iMin = i;
-          }
-          if ( fabs( dist[i] ) <= tol )
-            idInPln.insert( idNodes[i] );
-        }
-
-        // there should not be more than 4 nodes in bottom plane
-        if ( idInPln.size() > 1 )
-        {
-          DUMPSO( "### idInPln.size() = " << idInPln.size());
-          // idInPlane does not contain the first 3 nodes
-          if ( manyInPlane || idInPln.size() == 5)
-            return false; // all nodes in one plane
-          manyInPlane = true;
-
-          // set the 1-st node to be not in plane
-          for ( i = 3; i < 8; i++ ) {
-            if ( idInPln.find( idNodes[ i ] ) == idInPln.end() ) {
-              DUMPSO( "### Reset 0-th node");
-              swap( 0, i, idNodes, P );
-              break;
-            }
-          }
-
-          // reset to re-check second nodes
-          leastDist = DBL_MAX;
-          faceNodes.clear();
-          checkedId1.clear();
-          iLoop1 = 0;
-          break; // from iLoop2;
-        }
-
-        // check that the other 4 nodes are on the same side
-        bool sameSide = true;
-        bool isNeg = dist[ iMin == 3 ? 4 : 3 ] <= 0.;
-        for ( i = 3; sameSide && i < 8; i++ ) {
-          if ( i != iMin )
-            sameSide = ( isNeg == dist[i] <= 0.);
-        }
-
-        // keep best solution
-        if ( sameSide && minDist < leastDist ) {
-          leastDist = minDist;
-          faceNodes.clear();
-          faceNodes.insert( idNodes[ 1 ] );
-          faceNodes.insert( idNodes[ 2 ] );
-          faceNodes.insert( idNodes[ iMin ] );
-          DUMPSO( "loop " << iLoop2 << " id2 " << idNodes[ 1 ] << " id3 " << idNodes[ 2 ]
-                  << " leastDist = " << leastDist);
-          if ( leastDist <= DBL_MIN )
-            break;
-        }
-      }
-
-      // set next 3-d node to check
-      int iNext = 2 + iLoop2;
-      if ( iNext < 8 ) {
-        DUMPSO( "Try 2-nd");
-        swap ( 2, iNext, idNodes, P );
-      }
-    } // while ( iLoop2 < 6 )
-  } // iLoop1
-
-  if ( faceNodes.empty() ) return false;
-
-  // Put the faceNodes in proper places
-  for ( i = 4; i < 8; i++ ) {
-    if ( faceNodes.find( idNodes[ i ] ) != faceNodes.end() ) {
-      // find a place to put
-      int iTo = 1;
-      while ( faceNodes.find( idNodes[ iTo ] ) != faceNodes.end() )
-        iTo++;
-      DUMPSO( "Set faceNodes");
-      swap ( iTo, i, idNodes, P );
-    }
-  }
-
-
-  // Set nodes of the found bottom face in good order
-  DUMPSO( " Found bottom face: ");
-  i = SortQuadNodes( theMesh, idNodes );
-  if ( i ) {
-    gp_Pnt Ptmp = P[ i ];
-    P[ i ] = P[ i+1 ];
-    P[ i+1 ] = Ptmp;
-  }
-  //   else
-  //     for ( int ii = 0; ii < 4; ii++ ) {
-  //       const SMDS_MeshNode *n = theMesh->FindNode( idNodes[ii] );
-  //       DUMPSO( ii << "(" << idNodes[ii] <<") : "<<n->X()<<" "<<n->Y()<<" "<<n->Z());
-  //    }
-
-  // Gravity center of the top and bottom faces
-  gp_Pnt aGCb = ( P[0].XYZ() + P[1].XYZ() + P[2].XYZ() + P[3].XYZ() ) / 4.;
-  gp_Pnt aGCt = ( P[4].XYZ() + P[5].XYZ() + P[6].XYZ() + P[7].XYZ() ) / 4.;
-
-  // Get direction from the bottom to the top face
-  gp_Vec upDir ( aGCb, aGCt );
-  Standard_Real upDirSize = upDir.Magnitude();
-  if ( upDirSize <= gp::Resolution() ) return false;
-  upDir / upDirSize;
-
-  // Assure that the bottom face normal points up
-  gp_Vec Nb = gp_Vec (P[0], P[1]).Crossed( gp_Vec (P[0], P[2]) );
-  Nb += gp_Vec (P[0], P[2]).Crossed( gp_Vec (P[0], P[3]) );
-  if ( Nb.Dot( upDir ) < 0 ) {
-    DUMPSO( "Reverse bottom face");
-    swap( 1, 3, idNodes, P );
-  }
-
-  // Find 5-th node - the one closest to the 1-st among the last 4 nodes.
-  Standard_Real minDist = DBL_MAX;
-  for ( i = 4; i < 8; i++ ) {
-    // projection of P[i] to the plane defined by P[0] and upDir
-    gp_Pnt Pp = P[i].Translated( upDir * ( upDir.Dot( gp_Vec( P[i], P[0] ))));
-    Standard_Real sqDist = P[0].SquareDistance( Pp );
-    if ( sqDist < minDist ) {
-      minDist = sqDist;
-      iMin = i;
-    }
-  }
-  DUMPSO( "Set 4-th");
-  swap ( 4, iMin, idNodes, P );
-
-  // Set nodes of the top face in good order
-  DUMPSO( "Sort top face");
-  i = SortQuadNodes( theMesh, &idNodes[4] );
-  if ( i ) {
-    i += 4;
-    gp_Pnt Ptmp = P[ i ];
-    P[ i ] = P[ i+1 ];
-    P[ i+1 ] = Ptmp;
-  }
-
-  // Assure that direction of the top face normal is from the bottom face
-  gp_Vec Nt = gp_Vec (P[4], P[5]).Crossed( gp_Vec (P[4], P[6]) );
-  Nt += gp_Vec (P[4], P[6]).Crossed( gp_Vec (P[4], P[7]) );
-  if ( Nt.Dot( upDir ) < 0 ) {
-    DUMPSO( "Reverse top face");
-    swap( 5, 7, idNodes, P );
-  }
-
-  //   DUMPSO( "OUTPUT: ========================================");
-  //   for ( i = 0; i < 8; i++ ) {
-  //     float *p = ugrid->GetPoint(idNodes[i]);
-  //     DUMPSO( i << "(" << idNodes[i] << ") : " << p[0] << " " << p[1] << " " << p[2]);
-  //   }
-
-  return true;
-}*/
-
 //================================================================================
 /*!
  * \brief Return nodes linked to the given one
@@ -3934,8 +3637,7 @@ void SMESH_MeshEditor::Smooth (TIDSortedElemSet &          theElems,
                                double                      theTgtAspectRatio,
                                const bool                  the2D)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( theTgtAspectRatio < 1.0 )
     theTgtAspectRatio = 1.0;
@@ -4141,7 +3843,7 @@ void SMESH_MeshEditor::Smooth (TIDSortedElemSet &          theElems,
             // if ( posType != SMDS_TOP_3DSPACE )
             //   dist2 = pNode.SquareDistance( surface->Value( newUV.X(), newUV.Y() ));
             // if ( dist2 < dist1 )
-              uv = newUV;
+            uv = newUV;
           }
         }
         // store UV in the map
@@ -4569,11 +4271,7 @@ void SMESH_MeshEditor::sweepElement(const SMDS_MeshElement*               elem,
         std::swap( itNN[0],    itNN[1] );
         std::swap( prevNod[0], prevNod[1] );
         std::swap( nextNod[0], nextNod[1] );
-#if defined(__APPLE__)
         std::swap( isSingleNode[0], isSingleNode[1] );
-#else
-        isSingleNode.swap( isSingleNode[0], isSingleNode[1] );
-#endif
         if ( nbSame > 0 )
           sames[0] = 1 - sames[0];
         iNotSameNode = 1 - iNotSameNode;
@@ -4665,55 +4363,55 @@ void SMESH_MeshEditor::sweepElement(const SMDS_MeshElement*               elem,
         break;
       }
       case SMDSEntity_Triangle: // TRIANGLE --->
-        {
-          if ( nbDouble > 0 ) break;
-          if ( nbSame == 0 )       // ---> pentahedron
-            aNewElem = aMesh->AddVolume (prevNod[ 0 ], prevNod[ 1 ], prevNod[ 2 ],
-                                         nextNod[ 0 ], nextNod[ 1 ], nextNod[ 2 ] );
-
-          else if ( nbSame == 1 )  // ---> pyramid
-            aNewElem = aMesh->AddVolume (prevNod[ iBeforeSame ], prevNod[ iAfterSame ],
-                                         nextNod[ iAfterSame ],  nextNod[ iBeforeSame ],
-                                         nextNod[ iSameNode ]);
-
-          else // 2 same nodes:       ---> tetrahedron
-            aNewElem = aMesh->AddVolume (prevNod[ 0 ], prevNod[ 1 ], prevNod[ 2 ],
-                                         nextNod[ iNotSameNode ]);
-          break;
-        }
+      {
+        if ( nbDouble > 0 ) break;
+        if ( nbSame == 0 )       // ---> pentahedron
+          aNewElem = aMesh->AddVolume (prevNod[ 0 ], prevNod[ 1 ], prevNod[ 2 ],
+                                       nextNod[ 0 ], nextNod[ 1 ], nextNod[ 2 ] );
+
+        else if ( nbSame == 1 )  // ---> pyramid
+          aNewElem = aMesh->AddVolume (prevNod[ iBeforeSame ], prevNod[ iAfterSame ],
+                                       nextNod[ iAfterSame ],  nextNod[ iBeforeSame ],
+                                       nextNod[ iSameNode ]);
+
+        else // 2 same nodes:       ---> tetrahedron
+          aNewElem = aMesh->AddVolume (prevNod[ 0 ], prevNod[ 1 ], prevNod[ 2 ],
+                                       nextNod[ iNotSameNode ]);
+        break;
+      }
       case SMDSEntity_Quad_Edge: // sweep quadratic EDGE --->
+      {
+        if ( nbSame == 2 )
+          return;
+        if ( nbDouble+nbSame == 2 )
         {
-          if ( nbSame == 2 )
-            return;
-          if ( nbDouble+nbSame == 2 )
-          {
-            if(nbSame==0) {      // ---> quadratic quadrangle
-              aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1], nextNod[0],
-                                        prevNod[2], midlNod[1], nextNod[2], midlNod[0]);
-            }
-            else { //(nbSame==1) // ---> quadratic triangle
-              if(sames[0]==2) {
-                return; // medium node on axis
-              }
-              else if(sames[0]==0)
-                aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1],
-                                          prevNod[2], midlNod[1], nextNod[2] );
-              else // sames[0]==1
-                aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[0],
-                                          prevNod[2], nextNod[2], midlNod[0]);
-            }
+          if(nbSame==0) {      // ---> quadratic quadrangle
+            aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1], nextNod[0],
+                                      prevNod[2], midlNod[1], nextNod[2], midlNod[0]);
           }
-          else if ( nbDouble == 3 )
-          {
-            if ( nbSame == 0 ) {  // ---> bi-quadratic quadrangle
-              aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1], nextNod[0],
-                                        prevNod[2], midlNod[1], nextNod[2], midlNod[0], midlNod[2]);
+          else { //(nbSame==1) // ---> quadratic triangle
+            if(sames[0]==2) {
+              return; // medium node on axis
             }
+            else if(sames[0]==0)
+              aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1],
+                                        prevNod[2], midlNod[1], nextNod[2] );
+            else // sames[0]==1
+              aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[0],
+                                        prevNod[2], nextNod[2], midlNod[0]);
+          }
+        }
+        else if ( nbDouble == 3 )
+        {
+          if ( nbSame == 0 ) {  // ---> bi-quadratic quadrangle
+            aNewElem = aMesh->AddFace(prevNod[0], prevNod[1], nextNod[1], nextNod[0],
+                                      prevNod[2], midlNod[1], nextNod[2], midlNod[0], midlNod[2]);
           }
-          else
-            return;
-          break;
         }
+        else
+          return;
+        break;
+      }
       case SMDSEntity_Quadrangle: { // sweep QUADRANGLE --->
         if ( nbDouble > 0 ) break;
 
@@ -4935,8 +4633,8 @@ void SMESH_MeshEditor::sweepElement(const SMDS_MeshElement*               elem,
 
     if ( aNewElem ) {
       newElems.push_back( aNewElem );
-      myLastCreatedElems.Append(aNewElem);
-      srcElements.Append( elem );
+      myLastCreatedElems.push_back(aNewElem);
+      srcElements.push_back( elem );
     }
 
     // set new prev nodes
@@ -5026,19 +4724,19 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
       if ( !isQuadratic ) {
         if ( !aMesh->FindEdge( vecNewNodes[ 0 ]->second.back(),
                                vecNewNodes[ 1 ]->second.back())) {
-          myLastCreatedElems.Append(aMesh->AddEdge(vecNewNodes[ 0 ]->second.back(),
-                                                   vecNewNodes[ 1 ]->second.back()));
-          srcElements.Append( elem );
+          myLastCreatedElems.push_back(aMesh->AddEdge(vecNewNodes[ 0 ]->second.back(),
+                                                      vecNewNodes[ 1 ]->second.back()));
+          srcElements.push_back( elem );
         }
       }
       else {
         if ( !aMesh->FindEdge( vecNewNodes[ 0 ]->second.back(),
                                vecNewNodes[ 1 ]->second.back(),
                                vecNewNodes[ 2 ]->second.back())) {
-          myLastCreatedElems.Append(aMesh->AddEdge(vecNewNodes[ 0 ]->second.back(),
-                                                   vecNewNodes[ 1 ]->second.back(),
-                                                   vecNewNodes[ 2 ]->second.back()));
-          srcElements.Append( elem );
+          myLastCreatedElems.push_back(aMesh->AddEdge(vecNewNodes[ 0 ]->second.back(),
+                                                      vecNewNodes[ 1 ]->second.back(),
+                                                      vecNewNodes[ 2 ]->second.back()));
+          srcElements.push_back( elem );
         }
       }
     }
@@ -5066,14 +4764,14 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
           // make a new edge and a ceiling for a new edge
           const SMDS_MeshElement* edge;
           if ( ! ( edge = aMesh->FindEdge( n1, n2 ))) {
-            myLastCreatedElems.Append( edge = aMesh->AddEdge( n1, n2 )); // free link edge
-            srcElements.Append( myLastCreatedElems.Last() );
+            myLastCreatedElems.push_back( edge = aMesh->AddEdge( n1, n2 )); // free link edge
+            srcElements.push_back( myLastCreatedElems.back() );
           }
           n1 = vecNewNodes[ iNode ]->second.back();
           n2 = vecNewNodes[ iNext ]->second.back();
           if ( !aMesh->FindEdge( n1, n2 )) {
-            myLastCreatedElems.Append(aMesh->AddEdge( n1, n2 )); // new edge ceiling
-            srcElements.Append( edge );
+            myLastCreatedElems.push_back(aMesh->AddEdge( n1, n2 )); // new edge ceiling
+            srcElements.push_back( edge );
           }
         }
       }
@@ -5094,15 +4792,15 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
           // make an edge and a ceiling for a new edge
           // find medium node
           if ( !aMesh->FindEdge( n1, n2, n3 )) {
-            myLastCreatedElems.Append(aMesh->AddEdge( n1, n2, n3 )); // free link edge
-            srcElements.Append( elem );
+            myLastCreatedElems.push_back(aMesh->AddEdge( n1, n2, n3 )); // free link edge
+            srcElements.push_back( elem );
           }
           n1 = vecNewNodes[ iNode ]->second.back();
           n2 = vecNewNodes[ iNext ]->second.back();
           n3 = vecNewNodes[ iNode+nbn ]->second.back();
           if ( !aMesh->FindEdge( n1, n2, n3 )) {
-            myLastCreatedElems.Append(aMesh->AddEdge( n1, n2, n3 )); // ceiling edge
-            srcElements.Append( elem );
+            myLastCreatedElems.push_back(aMesh->AddEdge( n1, n2, n3 )); // ceiling edge
+            srcElements.push_back( elem );
           }
         }
       }
@@ -5195,8 +4893,8 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
                 if ( f )
                   aMesh->ChangeElementNodes( f, &newOrder[0], nbn );
                 else
-                  myLastCreatedElems.Append(aMesh->AddFace( newOrder[ 0 ], newOrder[ 1 ],
-                                                            newOrder[ 2 ] ));
+                  myLastCreatedElems.push_back(aMesh->AddFace( newOrder[ 0 ], newOrder[ 1 ],
+                                                               newOrder[ 2 ] ));
               }
             }
             else if ( nbn == 4 )       ///// quadrangle
@@ -5210,8 +4908,8 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
                 if ( f )
                   aMesh->ChangeElementNodes( f, &newOrder[0], nbn );
                 else
-                  myLastCreatedElems.Append(aMesh->AddFace( newOrder[ 0 ], newOrder[ 1 ],
-                                                            newOrder[ 2 ], newOrder[ 3 ]));
+                  myLastCreatedElems.push_back(aMesh->AddFace( newOrder[ 0 ], newOrder[ 1 ],
+                                                               newOrder[ 2 ], newOrder[ 3 ]));
               }
             }
             else if ( nbn == 6 && isQuadratic ) /////// quadratic triangle
@@ -5229,12 +4927,12 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
                 if ( f )
                   aMesh->ChangeElementNodes( f, &newOrder[0], nbn );
                 else
-                  myLastCreatedElems.Append(aMesh->AddFace( newOrder[ 0 ],
-                                                            newOrder[ 1 ],
-                                                            newOrder[ 2 ],
-                                                            newOrder[ 3 ],
-                                                            newOrder[ 4 ],
-                                                            newOrder[ 5 ] ));
+                  myLastCreatedElems.push_back(aMesh->AddFace( newOrder[ 0 ],
+                                                               newOrder[ 1 ],
+                                                               newOrder[ 2 ],
+                                                               newOrder[ 3 ],
+                                                               newOrder[ 4 ],
+                                                               newOrder[ 5 ] ));
               }
             }
             else if ( nbn == 8 && isQuadratic ) /////// quadratic quadrangle
@@ -5255,10 +4953,10 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
                 if ( f )
                   aMesh->ChangeElementNodes( f, &newOrder[0], nbn );
                 else
-                  myLastCreatedElems.Append(aMesh->AddFace(newOrder[ 0 ], newOrder[ 1 ],
-                                                           newOrder[ 2 ], newOrder[ 3 ],
-                                                           newOrder[ 4 ], newOrder[ 5 ],
-                                                           newOrder[ 6 ], newOrder[ 7 ]));
+                  myLastCreatedElems.push_back(aMesh->AddFace(newOrder[ 0 ], newOrder[ 1 ],
+                                                              newOrder[ 2 ], newOrder[ 3 ],
+                                                              newOrder[ 4 ], newOrder[ 5 ],
+                                                              newOrder[ 6 ], newOrder[ 7 ]));
               }
             }
             else if ( nbn == 9 && isQuadratic ) /////// bi-quadratic quadrangle
@@ -5280,11 +4978,11 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
                 if ( f )
                   aMesh->ChangeElementNodes( f, &newOrder[0], nbn );
                 else
-                  myLastCreatedElems.Append(aMesh->AddFace(newOrder[ 0 ], newOrder[ 1 ],
-                                                           newOrder[ 2 ], newOrder[ 3 ],
-                                                           newOrder[ 4 ], newOrder[ 5 ],
-                                                           newOrder[ 6 ], newOrder[ 7 ],
-                                                           newOrder[ 8 ]));
+                  myLastCreatedElems.push_back(aMesh->AddFace(newOrder[ 0 ], newOrder[ 1 ],
+                                                              newOrder[ 2 ], newOrder[ 3 ],
+                                                              newOrder[ 4 ], newOrder[ 5 ],
+                                                              newOrder[ 6 ], newOrder[ 7 ],
+                                                              newOrder[ 8 ]));
               }
             }
             else  //////// polygon
@@ -5303,8 +5001,8 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
               }
             }
 
-            while ( srcElements.Length() < myLastCreatedElems.Length() )
-              srcElements.Append( *srcEdge );
+            while ( srcElements.size() < myLastCreatedElems.size() )
+              srcElements.push_back( *srcEdge );
 
           }  // loop on free faces
 
@@ -5341,8 +5039,8 @@ void SMESH_MeshEditor::makeWalls (TNodeOfNodeListMap &     mapNewNodes,
 
         AddElement( nodeVec, anyFace.Init( elem ));
 
-        while ( srcElements.Length() < myLastCreatedElems.Length() )
-          srcElements.Append( elem );
+        while ( srcElements.size() < myLastCreatedElems.size() )
+          srcElements.push_back( elem );
       }
     }
   } // loop on swept elements
@@ -5362,11 +5060,16 @@ SMESH_MeshEditor::RotationSweep(TIDSortedElemSet   theElemSets[2],
                                 const bool         theMakeGroups,
                                 const bool         theMakeWalls)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
+
+  setElemsFirst( theElemSets );
+  myLastCreatedElems.reserve( theElemSets[0].size() * theNbSteps );
+  myLastCreatedNodes.reserve( theElemSets[1].size() * theNbSteps );
 
   // source elements for each generated one
   SMESH_SequenceOfElemPtr srcElems, srcNodes;
+  srcElems.reserve( theElemSets[0].size() );
+  srcNodes.reserve( theElemSets[1].size() );
 
   gp_Trsf aTrsf;
   aTrsf.SetRotation( theAxis, theAngle );
@@ -5386,7 +5089,6 @@ SMESH_MeshEditor::RotationSweep(TIDSortedElemSet   theElemSets[2],
                                      myMesh->NbFaces(ORDER_QUADRATIC) +
                                      myMesh->NbVolumes(ORDER_QUADRATIC) );
   // loop on theElemSets
-  setElemsFirst( theElemSets );
   TIDSortedElemSet::iterator itElem;
   for ( int is2ndSet = 0; is2ndSet < 2; ++is2ndSet )
   {
@@ -5438,8 +5140,8 @@ SMESH_MeshEditor::RotationSweep(TIDSortedElemSet   theElemSets[2],
               {
                 aTrsf2.Transforms( coord[0], coord[1], coord[2] );
                 newNode = aMesh->AddNode( coord[0], coord[1], coord[2] );
-                myLastCreatedNodes.Append(newNode);
-                srcNodes.Append( node );
+                myLastCreatedNodes.push_back(newNode);
+                srcNodes.push_back( node );
                 listNewNodes.push_back( newNode );
                 aTrsf2.Transforms( coord[0], coord[1], coord[2] );
               }
@@ -5448,8 +5150,8 @@ SMESH_MeshEditor::RotationSweep(TIDSortedElemSet   theElemSets[2],
               }
               // create a corner node
               newNode = aMesh->AddNode( coord[0], coord[1], coord[2] );
-              myLastCreatedNodes.Append(newNode);
-              srcNodes.Append( node );
+              myLastCreatedNodes.push_back(newNode);
+              srcNodes.push_back( node );
               listNewNodes.push_back( newNode );
             }
             else {
@@ -5755,12 +5457,12 @@ makeNodesByDirAndSew( SMESHDS_Mesh*                     mesh,
     P1 += myDir.XYZ() * nextStep();
 
     // try to search in sequence of existing nodes
-    // if myNodes.Length()>0 we 'nave to use given sequence
+    // if myNodes.size()>0 we 'nave to use given sequence
     // else - use all nodes of mesh
     const SMDS_MeshNode * node = 0;
     if ( myNodes.Length() > 0 ) {
       int i;
-      for(i=1; i<=myNodes.Length(); i++) {
+      for ( i = 1; i <= myNodes.Length(); i++ ) {
         gp_XYZ P2 = SMESH_TNodeXYZ( myNodes.Value(i) );
         if (( P1 - P2 ).SquareModulus() < myTolerance * myTolerance )
         {
@@ -5922,13 +5624,17 @@ SMESH_MeshEditor::ExtrusionSweep (TIDSortedElemSet     theElemSets[2],
                                   ExtrusParam&         theParams,
                                   TTElemOfElemListMap& newElemsMap)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
+
+  setElemsFirst( theElemSets );
+  myLastCreatedElems.reserve( theElemSets[0].size() * theParams.NbSteps() );
+  myLastCreatedNodes.reserve( theElemSets[1].size() * theParams.NbSteps() );
 
   // source elements for each generated one
   SMESH_SequenceOfElemPtr srcElems, srcNodes;
+  srcElems.reserve( theElemSets[0].size() );
+  srcNodes.reserve( theElemSets[1].size() );
 
-  setElemsFirst( theElemSets );
   const int nbSteps = theParams.NbSteps();
   theParams.SetElementsToUse( theElemSets[0], theElemSets[1] );
 
@@ -5987,8 +5693,8 @@ SMESH_MeshEditor::ExtrusionSweep (TIDSortedElemSet     theElemSets[2],
             list<const SMDS_MeshNode*>::iterator newNodesIt = listNewNodes.begin();
             for ( ; newNodesIt != listNewNodes.end(); ++newNodesIt )
             {
-              myLastCreatedNodes.Append( *newNodesIt );
-              srcNodes.Append( node );
+              myLastCreatedNodes.push_back( *newNodesIt );
+              srcNodes.push_back( node );
             }
           }
           else
@@ -6029,8 +5735,7 @@ SMESH_MeshEditor::ExtrusionAlongTrack (TIDSortedElemSet     theElements[2],
                                        const gp_Pnt&        theRefPoint,
                                        const bool           theMakeGroups)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   int aNbE;
   std::list<double> aPrms;
@@ -6144,7 +5849,7 @@ SMESH_MeshEditor::ExtrusionAlongTrack (TIDSortedElemSet     theElements[2],
         makeEdgePathPoints(aPrms, aTrackEdge,(aN1->GetID()==startNid), LPP);
         LLPPs.push_back(LPP);
         UsedNums.Add(k);
-        // update startN for search following egde
+        // update startN for search following edge
         if( aN1->GetID() == startNid ) startNid = aN2->GetID();
         else startNid = aN1->GetID();
         break;
@@ -6204,8 +5909,7 @@ SMESH_MeshEditor::ExtrusionAlongTrack (TIDSortedElemSet     theElements[2],
                                        const gp_Pnt&        theRefPoint,
                                        const bool           theMakeGroups)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   int aNbE;
   std::list<double> aPrms;
@@ -6443,7 +6147,7 @@ SMESH_MeshEditor::ExtrusionAlongTrack (TIDSortedElemSet     theElements[2],
         makeEdgePathPoints(aPrms, aTrackEdge, aN1isOK, LPP);
         LLPPs.push_back(LPP);
         UsedNums.Add(k);
-        // update startN for search following egde
+        // update startN for search following edge
         if ( aN1isOK ) aVprev = aV2;
         else           aVprev = aV1;
         break;
@@ -6684,13 +6388,13 @@ SMESH_MeshEditor::makeExtrElements(TIDSortedElemSet                  theElemSets
               // create additional node
               gp_XYZ midP = 0.5 * ( aPN1.XYZ() + aPN0.XYZ() );
               const SMDS_MeshNode* newNode = aMesh->AddNode( midP.X(), midP.Y(), midP.Z() );
-              myLastCreatedNodes.Append(newNode);
-              srcNodes.Append( node );
+              myLastCreatedNodes.push_back(newNode);
+              srcNodes.push_back( node );
               listNewNodes.push_back( newNode );
             }
             const SMDS_MeshNode* newNode = aMesh->AddNode( aPN1.X(), aPN1.Y(), aPN1.Z() );
-            myLastCreatedNodes.Append(newNode);
-            srcNodes.Append( node );
+            myLastCreatedNodes.push_back(newNode);
+            srcNodes.push_back( node );
             listNewNodes.push_back( newNode );
 
             aPN0 = aPN1;
@@ -6716,8 +6420,8 @@ SMESH_MeshEditor::makeExtrElements(TIDSortedElemSet                  theElemSets
               double y = ( N->Y() + P.Y() )/2.;
               double z = ( N->Z() + P.Z() )/2.;
               const SMDS_MeshNode* newN = aMesh->AddNode(x,y,z);
-              srcNodes.Append( node );
-              myLastCreatedNodes.Append(newN);
+              srcNodes.push_back( node );
+              myLastCreatedNodes.push_back(newN);
               aNodes[2*i] = newN;
               aNodes[2*i+1] = N;
               P = gp_XYZ(N->X(),N->Y(),N->Z());
@@ -6810,8 +6514,8 @@ SMESH_MeshEditor::Transform (TIDSortedElemSet & theElems,
                              const bool         theMakeGroups,
                              SMESH_Mesh*        theTargetMesh)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
+  myLastCreatedElems.reserve( theElems.size() );
 
   bool needReverse = false;
   string groupPostfix;
@@ -6906,14 +6610,14 @@ SMESH_MeshEditor::Transform (TIDSortedElemSet & theElems,
         if ( theTargetMesh ) {
           const SMDS_MeshNode * newNode = aTgtMesh->AddNode( coord[0], coord[1], coord[2] );
           n2n_isnew.first->second = newNode;
-          myLastCreatedNodes.Append(newNode);
-          srcNodes.Append( node );
+          myLastCreatedNodes.push_back(newNode);
+          srcNodes.push_back( node );
         }
         else if ( theCopy ) {
           const SMDS_MeshNode * newNode = aMesh->AddNode( coord[0], coord[1], coord[2] );
           n2n_isnew.first->second = newNode;
-          myLastCreatedNodes.Append(newNode);
-          srcNodes.Append( node );
+          myLastCreatedNodes.push_back(newNode);
+          srcNodes.push_back( node );
         }
         else {
           aMesh->MoveNode( node, coord[0], coord[1], coord[2] );
@@ -7003,7 +6707,7 @@ SMESH_MeshEditor::Transform (TIDSortedElemSet & theElems,
     if ( editor ) {
       // copy in this or a new mesh
       if ( editor->AddElement( nodes, elemType.Init( elem, /*basicOnly=*/false )))
-        srcElems.Append( elem );
+        srcElems.push_back( elem );
     }
     else {
       // reverse element as it was reversed by transformation
@@ -7014,7 +6718,7 @@ SMESH_MeshEditor::Transform (TIDSortedElemSet & theElems,
   } // loop on elements
 
   if ( editor && editor != this )
-    myLastCreatedElems = editor->myLastCreatedElems;
+    myLastCreatedElems.swap( editor->myLastCreatedElems );
 
   PGroupIDs newGroupIDs;
 
@@ -7025,14 +6729,97 @@ SMESH_MeshEditor::Transform (TIDSortedElemSet & theElems,
   return newGroupIDs;
 }
 
+//================================================================================
+/*!
+ * \brief Make an offset mesh from a source 2D mesh
+ *  \param [in] theElements - source faces
+ *  \param [in] theValue - offset value
+ *  \param [out] theTgtMesh - a mesh to add offset elements to
+ *  \param [in] theMakeGroups - to generate groups
+ *  \return PGroupIDs - IDs of created groups
+ */
+//================================================================================
+
+SMESH_MeshEditor::PGroupIDs SMESH_MeshEditor::Offset( TIDSortedElemSet & theElements,
+                                                      const double       theValue,
+                                                      SMESH_Mesh*        theTgtMesh,
+                                                      const bool         theMakeGroups,
+                                                      const bool         theFixSelfIntersection)
+{
+  SMESHDS_Mesh*    meshDS = GetMeshDS();
+  SMESHDS_Mesh* tgtMeshDS = theTgtMesh->GetMeshDS();
+  SMESH_MeshEditor tgtEditor( theTgtMesh );
+
+  SMDS_ElemIteratorPtr eIt;
+  if ( theElements.empty() ) eIt = meshDS->elementsIterator( SMDSAbs_Face );
+  else                       eIt = SMESHUtils::elemSetIterator( theElements );
+
+  SMESH_MeshAlgos::TEPairVec new2OldFaces;
+  SMESH_MeshAlgos::TNPairVec new2OldNodes;
+  std::unique_ptr< SMDS_Mesh > offsetMesh
+    ( SMESH_MeshAlgos::MakeOffset( eIt, *meshDS, theValue,
+                                   theFixSelfIntersection,
+                                   new2OldFaces, new2OldNodes ));
+
+  offsetMesh->Modified();
+  offsetMesh->CompactMesh(); // make IDs start from 1
+
+  // source elements for each generated one
+  SMESH_SequenceOfElemPtr srcElems, srcNodes;
+  srcElems.reserve( new2OldFaces.size() );
+  srcNodes.reserve( new2OldNodes.size() );
+
+  ClearLastCreated();
+  myLastCreatedElems.reserve( new2OldFaces.size() );
+  myLastCreatedNodes.reserve( new2OldNodes.size() );
+
+  // copy offsetMesh to theTgtMesh
+
+  int idShift = meshDS->MaxNodeID();
+  for ( size_t i = 0; i < new2OldNodes.size(); ++i )
+    if ( const SMDS_MeshNode* n = new2OldNodes[ i ].first )
+    {
+      if ( n->NbInverseElements() > 0 )
+      {
+        const SMDS_MeshNode* n2 =
+          tgtMeshDS->AddNodeWithID( n->X(), n->Y(), n->Z(), idShift + n->GetID() );
+        myLastCreatedNodes.push_back( n2 );
+        srcNodes.push_back( new2OldNodes[ i ].second );
+      }
+    }
+
+  ElemFeatures elemType;
+  for ( size_t i = 0; i < new2OldFaces.size(); ++i )
+    if ( const SMDS_MeshElement* f = new2OldFaces[ i ].first )
+    {
+      elemType.Init( f );
+      elemType.myNodes.clear();
+      for ( SMDS_NodeIteratorPtr nIt = f->nodeIterator(); nIt->more(); )
+      {
+        const SMDS_MeshNode* n2 = nIt->next();
+        elemType.myNodes.push_back( tgtMeshDS->FindNode( idShift + n2->GetID() ));
+      }
+      tgtEditor.AddElement( elemType.myNodes, elemType );
+      srcElems.push_back( new2OldFaces[ i ].second );
+    }
+
+  myLastCreatedElems.swap( tgtEditor.myLastCreatedElems );
+
+  PGroupIDs newGroupIDs;
+  if ( theMakeGroups )
+    newGroupIDs = generateGroups( srcNodes, srcElems, "offset", theTgtMesh, false );
+
+  return newGroupIDs;
+}
+
 //=======================================================================
 /*!
  * \brief Create groups of elements made during transformation
  *  \param nodeGens - nodes making corresponding myLastCreatedNodes
  *  \param elemGens - elements making corresponding myLastCreatedElems
- *  \param postfix - to append to names of new groups
+ *  \param postfix - to push_back to names of new groups
  *  \param targetMesh - mesh to create groups in
- *  \param topPresent - is there "top" elements that are created by sweeping
+ *  \param topPresent - is there are "top" elements that are created by sweeping
  */
 //=======================================================================
 
@@ -7085,30 +6872,30 @@ SMESH_MeshEditor::generateGroups(const SMESH_SequenceOfElemPtr& nodeGens,
   {
     const SMESH_SequenceOfElemPtr& gens  = isNodes ? nodeGens : elemGens;
     const SMESH_SequenceOfElemPtr& elems = isNodes ? myLastCreatedNodes : myLastCreatedElems;
-    if ( gens.Length() != elems.Length() )
+    if ( gens.size() != elems.size() )
       throw SALOME_Exception("SMESH_MeshEditor::generateGroups(): invalid args");
 
     // loop on created elements
-    for (int iElem = 1; iElem <= elems.Length(); ++iElem )
+    for (size_t iElem = 0; iElem < elems.size(); ++iElem )
     {
-      const SMDS_MeshElement* sourceElem = gens( iElem );
+      const SMDS_MeshElement* sourceElem = gens[ iElem ];
       if ( !sourceElem ) {
         MESSAGE("generateGroups(): NULL source element");
         continue;
       }
       list< TOldNewGroup > & groupsOldNew = groupsByType[ sourceElem->GetType() ];
       if ( groupsOldNew.empty() ) { // no groups of this type at all
-        while ( iElem < gens.Length() && gens( iElem+1 ) == sourceElem )
+        while ( iElem+1 < gens.size() && gens[ iElem+1 ] == sourceElem )
           ++iElem; // skip all elements made by sourceElem
         continue;
       }
       // collect all elements made by the iElem-th sourceElem
       resultElems.clear();
-      if ( const SMDS_MeshElement* resElem = elems( iElem ))
+      if ( const SMDS_MeshElement* resElem = elems[ iElem ])
         if ( resElem != sourceElem )
           resultElems.push_back( resElem );
-      while ( iElem < gens.Length() && gens( iElem+1 ) == sourceElem )
-        if ( const SMDS_MeshElement* resElem = elems( ++iElem ))
+      while ( iElem+1 < gens.size() && gens[ iElem+1 ] == sourceElem )
+        if ( const SMDS_MeshElement* resElem = elems[ ++iElem ])
           if ( resElem != sourceElem )
             resultElems.push_back( resElem );
 
@@ -7148,7 +6935,7 @@ SMESH_MeshEditor::generateGroups(const SMESH_SequenceOfElemPtr& nodeGens,
           {
             SMDS_MeshGroup & newTopGroup = gOldNew->get<2>()->SMDSGroup();
             newTopGroup.Add( topElem );
-         }
+          }
         }
       }
     } // loop on created elements
@@ -7235,8 +7022,7 @@ void SMESH_MeshEditor::FindCoincidentNodes (TIDSortedNodeSet &   theNodes,
                                             TListOfListOfNodes & theGroupsOfNodes,
                                             bool                 theSeparateCornersAndMedium)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( myMesh->NbEdges  ( ORDER_QUADRATIC ) +
        myMesh->NbFaces  ( ORDER_QUADRATIC ) +
@@ -7349,8 +7135,7 @@ int SMESH_MeshEditor::SimplifyFace (const vector<const SMDS_MeshNode *>& faceNod
 void SMESH_MeshEditor::MergeNodes (TListOfListOfNodes & theGroupsOfNodes,
                                    const bool           theAvoidMakingHoles)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   SMESHDS_Mesh* mesh = GetMeshDS();
 
@@ -7975,39 +7760,34 @@ private:
 void SMESH_MeshEditor::FindEqualElements(TIDSortedElemSet &        theElements,
                                          TListOfListOfElementsID & theGroupsOfElementsID)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   typedef map< SortableElement, int > TMapOfNodeSet;
   typedef list<int> TGroupOfElems;
 
-  if ( theElements.empty() )
-  { // get all elements in the mesh
-    SMDS_ElemIteratorPtr eIt = GetMeshDS()->elementsIterator();
-    while ( eIt->more() )
-      theElements.insert( theElements.end(), eIt->next() );
-  }
+  SMDS_ElemIteratorPtr elemIt;
+  if ( theElements.empty() ) elemIt = GetMeshDS()->elementsIterator();
+  else                       elemIt = SMESHUtils::elemSetIterator( theElements );
 
   vector< TGroupOfElems > arrayOfGroups;
   TGroupOfElems groupOfElems;
   TMapOfNodeSet mapOfNodeSet;
 
-  TIDSortedElemSet::iterator elemIt = theElements.begin();
-  for ( int i = 0; elemIt != theElements.end(); ++elemIt )
+  for ( int iGroup = 0; elemIt->more(); )
   {
-    const SMDS_MeshElement* curElem = *elemIt;
+    const SMDS_MeshElement* curElem = elemIt->next();
     SortableElement SE(curElem);
     // check uniqueness
-    pair< TMapOfNodeSet::iterator, bool> pp = mapOfNodeSet.insert(make_pair(SE, i));
+    pair< TMapOfNodeSet::iterator, bool> pp = mapOfNodeSet.insert(make_pair(SE, iGroup));
     if ( !pp.second ) { // one more coincident elem
       TMapOfNodeSet::iterator& itSE = pp.first;
-      int ind = (*itSE).second;
-      arrayOfGroups[ind].push_back( curElem->GetID() );
+      int iG = itSE->second;
+      arrayOfGroups[ iG ].push_back( curElem->GetID() );
     }
     else {
       arrayOfGroups.push_back( groupOfElems );
       arrayOfGroups.back().push_back( curElem->GetID() );
-      i++;
+      iGroup++;
     }
   }
 
@@ -8030,8 +7810,7 @@ void SMESH_MeshEditor::FindEqualElements(TIDSortedElemSet &        theElements,
 
 void SMESH_MeshEditor::MergeElements(TListOfListOfElementsID & theGroupsOfElementsID)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   typedef list<int> TListOfIDs;
   TListOfIDs rmElemIds; // IDs of elems to remove
@@ -8233,7 +8012,7 @@ bool SMESH_MeshEditor::FindFreeBorder (const SMDS_MeshNode*             theFirst
       if ( contNodes[0].empty() && contNodes[1].empty() )
         return false;
 
-      // append the best free border
+      // push_back the best free border
       cNL = & contNodes[ contNodes[0].empty() ? 1 : 0 ];
       cFL = & contFaces[ contFaces[0].empty() ? 1 : 0 ];
       theNodes.pop_back(); // remove nIgnore
@@ -8283,8 +8062,7 @@ SMESH_MeshEditor::SewFreeBorder (const SMDS_MeshNode* theBordFirstNode,
                                  const bool           toCreatePolygons,
                                  const bool           toCreatePolyedrs)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   Sew_Error aResult = SEW_OK;
 
@@ -8737,13 +8515,13 @@ SMESH_MeshEditor::SewFreeBorder (const SMDS_MeshNode* theBordFirstNode,
   // get new segments
   TIDSortedElemSet segments;
   SMESH_SequenceOfElemPtr newFaces;
-  for ( int i = 1; i <= myLastCreatedElems.Length(); ++i )
+  for ( size_t i = 0; i < myLastCreatedElems.size(); ++i )
   {
-    if ( !myLastCreatedElems(i) ) continue;
-    if ( myLastCreatedElems(i)->GetType() == SMDSAbs_Edge )
-      segments.insert( segments.end(), myLastCreatedElems(i) );
+    if ( !myLastCreatedElems[i] ) continue;
+    if ( myLastCreatedElems[i]->GetType() == SMDSAbs_Edge )
+      segments.insert( segments.end(), myLastCreatedElems[i] );
     else
-      newFaces.Append( myLastCreatedElems(i) );
+      newFaces.push_back( myLastCreatedElems[i] );
   }
   // get segments adjacent to merged nodes
   TListOfListOfNodes::iterator groupIt = nodeGroupsToMerge.begin();
@@ -8778,7 +8556,7 @@ SMESH_MeshEditor::SewFreeBorder (const SMDS_MeshNode* theBordFirstNode,
     myLastCreatedElems = newFaces;
     TIDSortedElemSet::iterator seg = segments.begin();
     for ( ; seg != segments.end(); ++seg )
-      myLastCreatedElems.Append( *seg );
+      myLastCreatedElems.push_back( *seg );
   }
 
   return aResult;
@@ -8848,7 +8626,7 @@ void SMESH_MeshEditor::InsertNodesIntoLink(const SMDS_MeshElement*     theElemen
       if ( newElems[i] )
       {
         aMesh->SetMeshElementOnShape( newElems[i], theElement->getshapeId() );
-        myLastCreatedElems.Append( newElems[i] );
+        myLastCreatedElems.push_back( newElems[i] );
       }
     ReplaceElemInGroups( theElement, newElems, aMesh );
     aMesh->RemoveElement( theElement );
@@ -9109,7 +8887,7 @@ void SMESH_MeshEditor::InsertNodesIntoLink(const SMDS_MeshElement*     theElemen
     if ( newElems[i] )
     {
       aMesh->SetMeshElementOnShape( newElems[i], theFace->getshapeId() );
-      myLastCreatedElems.Append( newElems[i] );
+      myLastCreatedElems.push_back( newElems[i] );
     }
   ReplaceElemInGroups( theFace, newElems, aMesh );
   aMesh->RemoveElement(theFace);
@@ -9125,8 +8903,7 @@ void SMESH_MeshEditor::UpdateVolumes (const SMDS_MeshNode*        theBetweenNode
                                       const SMDS_MeshNode*        theBetweenNode2,
                                       list<const SMDS_MeshNode*>& theNodesToInsert)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   SMDS_ElemIteratorPtr invElemIt = theBetweenNode1->GetInverseElementIterator(SMDSAbs_Volume);
   while (invElemIt->more()) { // loop on inverse elements of theBetweenNode1
@@ -9188,7 +8965,7 @@ void SMESH_MeshEditor::UpdateVolumes (const SMDS_MeshNode*        theBetweenNode
     if ( SMDS_MeshElement* newElem = aMesh->AddPolyhedralVolume( poly_nodes, quantities ))
     {
       aMesh->SetMeshElementOnShape( newElem, elem->getshapeId() );
-      myLastCreatedElems.Append( newElem );
+      myLastCreatedElems.push_back( newElem );
       ReplaceElemInGroups( elem, newElem, aMesh );
     }
     aMesh->RemoveElement( elem );
@@ -9306,52 +9083,52 @@ int SMESH_MeshEditor::convertElemToQuadratic(SMESHDS_SubMesh *   theSm,
     switch( aType )
     {
     case SMDSAbs_Edge :
-      {
-        NewElem = theHelper.AddEdge(nodes[0], nodes[1], id, theForce3d);
-        break;
-      }
+    {
+      NewElem = theHelper.AddEdge(nodes[0], nodes[1], id, theForce3d);
+      break;
+    }
     case SMDSAbs_Face :
+    {
+      switch(nbNodes)
       {
-        switch(nbNodes)
-        {
-        case 3:
-          NewElem = theHelper.AddFace(nodes[0], nodes[1], nodes[2], id, theForce3d);
-          break;
-        case 4:
-          NewElem = theHelper.AddFace(nodes[0], nodes[1], nodes[2], nodes[3], id, theForce3d);
-          break;
-        default:
-          NewElem = theHelper.AddPolygonalFace(nodes, id, theForce3d);
-        }
+      case 3:
+        NewElem = theHelper.AddFace(nodes[0], nodes[1], nodes[2], id, theForce3d);
+        break;
+      case 4:
+        NewElem = theHelper.AddFace(nodes[0], nodes[1], nodes[2], nodes[3], id, theForce3d);
         break;
+      default:
+        NewElem = theHelper.AddPolygonalFace(nodes, id, theForce3d);
       }
+      break;
+    }
     case SMDSAbs_Volume :
+    {
+      switch( aGeomType )
       {
-        switch( aGeomType )
-        {
-        case SMDSEntity_Tetra:
-          NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], id, theForce3d);
-          break;
-        case SMDSEntity_Pyramid:
-          NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], nodes[4], id, theForce3d);
-          break;
-        case SMDSEntity_Penta:
-        case SMDSEntity_Quad_Penta:
-        case SMDSEntity_BiQuad_Penta:
-          NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], nodes[4], nodes[5], id, theForce3d);
-          break;
-        case SMDSEntity_Hexa:
-        case SMDSEntity_Quad_Hexa:
-        case SMDSEntity_TriQuad_Hexa:
-          NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3],
-                                        nodes[4], nodes[5], nodes[6], nodes[7], id, theForce3d);
-          break;
-        case SMDSEntity_Hexagonal_Prism:
-        default:
-          NewElem = theHelper.AddPolyhedralVolume(nodes, nbNodeInFaces, id, theForce3d);
-        }
+      case SMDSEntity_Tetra:
+        NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], id, theForce3d);
+        break;
+      case SMDSEntity_Pyramid:
+        NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], nodes[4], id, theForce3d);
+        break;
+      case SMDSEntity_Penta:
+      case SMDSEntity_Quad_Penta:
+      case SMDSEntity_BiQuad_Penta:
+        NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3], nodes[4], nodes[5], id, theForce3d);
+        break;
+      case SMDSEntity_Hexa:
+      case SMDSEntity_Quad_Hexa:
+      case SMDSEntity_TriQuad_Hexa:
+        NewElem = theHelper.AddVolume(nodes[0], nodes[1], nodes[2], nodes[3],
+                                      nodes[4], nodes[5], nodes[6], nodes[7], id, theForce3d);
         break;
+      case SMDSEntity_Hexagonal_Prism:
+      default:
+        NewElem = theHelper.AddPolyhedralVolume(nodes, nbNodeInFaces, id, theForce3d);
       }
+      break;
+    }
     default :
       continue;
     }
@@ -9729,7 +9506,7 @@ void SMESH_MeshEditor::ConvertToQuadratic(const bool        theForce3d,
     if( newElem && smDS )
       smDS->AddElement( newElem );
 
-     // remove central nodes
+    // remove central nodes
     for ( size_t i = nodes.size() - nbCentralNodes; i < nodes.size(); ++i )
       if ( nodes[i]->NbInverseElements() == 0 )
         meshDS->RemoveFreeNode( nodes[i], smDS, /*fromGroups=*/true );
@@ -9863,7 +9640,7 @@ void SMESH_MeshEditor::ConvertFromQuadratic(TIDSortedElemSet& theElements)
   }
 
   // replace given elements by linear ones
-  SMDS_ElemIteratorPtr elemIt = elemSetIterator( theElements );
+  SMDS_ElemIteratorPtr elemIt = SMESHUtils::elemSetIterator( theElements );
   removeQuadElem( /*theSm=*/0, elemIt, /*theShapeID=*/0 );
 
   // we need to convert remaining elements whose all medium nodes are in mediumNodeIDs
@@ -9915,7 +9692,7 @@ void SMESH_MeshEditor::ConvertFromQuadratic(TIDSortedElemSet& theElements)
       }
     }
   }
-  elemIt = elemSetIterator( moreElemsToConvert );
+  elemIt = SMESHUtils::elemSetIterator( moreElemsToConvert );
   removeQuadElem( /*theSm=*/0, elemIt, /*theShapeID=*/0 );
 }
 
@@ -9932,8 +9709,7 @@ SMESH_MeshEditor::SewSideElements (TIDSortedElemSet&    theSide1,
                                    const SMDS_MeshNode* theSecondNode1,
                                    const SMDS_MeshNode* theSecondNode2)
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( theSide1.size() != theSide2.size() )
     return SEW_DIFF_NB_OF_ELEMENTS;
@@ -10209,12 +9985,12 @@ SMESH_MeshEditor::SewSideElements (TIDSortedElemSet&    theSide1,
 
   if ( faceSet1.size() != faceSet2.size() ) {
     // delete temporary faces: they are in reverseElements of actual nodes
-//    SMDS_FaceIteratorPtr tmpFaceIt = aTmpFacesMesh.facesIterator();
-//    while ( tmpFaceIt->more() )
-//      aTmpFacesMesh.RemoveElement( tmpFaceIt->next() );
-//    list<const SMDS_MeshElement* >::iterator tmpFaceIt = tempFaceList.begin();
-//    for (; tmpFaceIt !=tempFaceList.end(); ++tmpFaceIt)
-//      aMesh->RemoveElement(*tmpFaceIt);
+    //    SMDS_FaceIteratorPtr tmpFaceIt = aTmpFacesMesh.facesIterator();
+    //    while ( tmpFaceIt->more() )
+    //      aTmpFacesMesh.RemoveElement( tmpFaceIt->next() );
+    //    list<const SMDS_MeshElement* >::iterator tmpFaceIt = tempFaceList.begin();
+    //    for (; tmpFaceIt !=tempFaceList.end(); ++tmpFaceIt)
+    //      aMesh->RemoveElement(*tmpFaceIt);
     MESSAGE("Diff nb of faces");
     return SEW_TOPO_DIFF_SETS_OF_ELEMENTS;
   }
@@ -10353,7 +10129,7 @@ SMESH_MeshEditor::SewSideElements (TIDSortedElemSet&    theSide1,
 
   if ( aResult == SEW_OK &&
        ( //linkIt[0] != linkList[0].end() ||
-         !faceSetPtr[0]->empty() || !faceSetPtr[1]->empty() )) {
+        !faceSetPtr[0]->empty() || !faceSetPtr[1]->empty() )) {
     MESSAGE( (linkIt[0] != linkList[0].end()) <<" "<< (faceSetPtr[0]->empty()) <<
              " " << (faceSetPtr[1]->empty()));
     aResult = SEW_TOPO_DIFF_SETS_OF_ELEMENTS;
@@ -10364,9 +10140,9 @@ SMESH_MeshEditor::SewSideElements (TIDSortedElemSet&    theSide1,
   // ====================================================================
 
   // delete temporary faces
-//  SMDS_FaceIteratorPtr tmpFaceIt = aTmpFacesMesh.facesIterator();
-//  while ( tmpFaceIt->more() )
-//    aTmpFacesMesh.RemoveElement( tmpFaceIt->next() );
+  //  SMDS_FaceIteratorPtr tmpFaceIt = aTmpFacesMesh.facesIterator();
+  //  while ( tmpFaceIt->more() )
+  //    aTmpFacesMesh.RemoveElement( tmpFaceIt->next() );
   list<const SMDS_MeshElement* >::iterator tmpFaceIt = tempFaceList.begin();
   for (; tmpFaceIt !=tempFaceList.end(); ++tmpFaceIt)
     aMesh->RemoveElement(*tmpFaceIt);
@@ -10598,52 +10374,602 @@ SMESH_MeshEditor::FindMatchingNodes(set<const SMDS_MeshElement*>& theSide1,
   return SEW_OK;
 }
 
-//================================================================================
-/*!
- * \brief Create elements equal (on same nodes) to given ones
- *  \param [in] theElements - a set of elems to duplicate. If it is empty, all
- *              elements of the uppest dimension are duplicated.
- */
-//================================================================================
-
-void SMESH_MeshEditor::DoubleElements( const TIDSortedElemSet& theElements )
+namespace // automatically find theAffectedElems for DoubleNodes()
 {
-  ClearLastCreated();
-  SMESHDS_Mesh* mesh = GetMeshDS();
+  bool isOut( const SMDS_MeshNode* n, const gp_XYZ& norm, const SMDS_MeshElement* elem );
 
-  // get an element type and an iterator over elements
-
-  SMDSAbs_ElementType type = SMDSAbs_All;
-  SMDS_ElemIteratorPtr elemIt;
-  vector< const SMDS_MeshElement* > allElems;
-  if ( theElements.empty() )
+  //--------------------------------------------------------------------------------
+  // Nodes shared by adjacent FissureBorder's.
+  // 1 node  if FissureBorder separates faces
+  // 2 nodes if FissureBorder separates volumes
+  struct SubBorder
   {
-    if ( mesh->NbNodes() == 0 )
-      return;
-    // get most complex type
-    SMDSAbs_ElementType types[SMDSAbs_NbElementTypes] = {
-      SMDSAbs_Volume, SMDSAbs_Face, SMDSAbs_Edge,
-      SMDSAbs_0DElement, SMDSAbs_Ball, SMDSAbs_Node
-    };
-    for ( int i = 0; i < SMDSAbs_NbElementTypes; ++i )
-      if ( mesh->GetMeshInfo().NbElements( types[i] ))
-      {
-        type = types[i];
+    const SMDS_MeshNode* _nodes[2];
+    int                  _nbNodes;
+
+    SubBorder( const SMDS_MeshNode* n1, const SMDS_MeshNode* n2 = 0 )
+    {
+      _nodes[0] = n1;
+      _nodes[1] = n2;
+      _nbNodes = bool( n1 ) + bool( n2 );
+      if ( _nbNodes == 2 && n1 > n2 )
+        std::swap( _nodes[0], _nodes[1] );
+    }
+    bool operator<( const SubBorder& other ) const
+    {
+      for ( int i = 0; i < _nbNodes; ++i )
+      {
+        if ( _nodes[i] < other._nodes[i] ) return true;
+        if ( _nodes[i] > other._nodes[i] ) return false;
+      }
+      return false;
+    }
+  };
+
+  //--------------------------------------------------------------------------------
+  // Map a SubBorder to all FissureBorder it bounds
+  struct FissureBorder;
+  typedef std::map< SubBorder, std::vector< FissureBorder* > > TBorderLinks;
+  typedef TBorderLinks::iterator                               TMappedSub;
+
+  //--------------------------------------------------------------------------------
+  /*!
+   * \brief Element border (volume facet or face edge) at a fissure
+   */
+  struct FissureBorder
+  {
+    std::vector< const SMDS_MeshNode* > _nodes;    // border nodes
+    const SMDS_MeshElement*             _elems[2]; // volume or face adjacent to fissure
+
+    std::vector< TMappedSub           > _mappedSubs;  // Sub() in TBorderLinks map
+    std::vector< const SMDS_MeshNode* > _sortedNodes; // to compare FissureBorder's
+
+    FissureBorder( FissureBorder && from ) // move constructor
+    {
+      std::swap( _nodes,       from._nodes );
+      std::swap( _sortedNodes, from._sortedNodes );
+      _elems[0] = from._elems[0];
+      _elems[1] = from._elems[1];
+    }
+
+    FissureBorder( const SMDS_MeshElement*                  elemToDuplicate,
+                   std::vector< const SMDS_MeshElement* > & adjElems)
+      : _nodes( elemToDuplicate->NbCornerNodes() )
+    {
+      for ( size_t i = 0; i < _nodes.size(); ++i )
+        _nodes[i] = elemToDuplicate->GetNode( i );
+
+      SMDSAbs_ElementType type = SMDSAbs_ElementType( elemToDuplicate->GetType() + 1 );
+      findAdjacent( type, adjElems );
+    }
+
+    FissureBorder( const SMDS_MeshNode**                    nodes,
+                   const size_t                             nbNodes,
+                   const SMDSAbs_ElementType                adjElemsType,
+                   std::vector< const SMDS_MeshElement* > & adjElems)
+      : _nodes( nodes, nodes + nbNodes )
+    {
+      findAdjacent( adjElemsType, adjElems );
+    }
+
+    void findAdjacent( const SMDSAbs_ElementType                adjElemsType,
+                       std::vector< const SMDS_MeshElement* > & adjElems)
+    {
+      _elems[0] = _elems[1] = 0;
+      adjElems.clear();
+      if ( SMDS_Mesh::GetElementsByNodes( _nodes, adjElems, adjElemsType ))
+        for ( size_t i = 0; i < adjElems.size() && i < 2; ++i )
+          _elems[i] = adjElems[i];
+    }
+
+    bool operator<( const FissureBorder& other ) const
+    {
+      return GetSortedNodes() < other.GetSortedNodes();
+    }
+
+    const std::vector< const SMDS_MeshNode* >& GetSortedNodes() const
+    {
+      if ( _sortedNodes.empty() && !_nodes.empty() )
+      {
+        FissureBorder* me = const_cast<FissureBorder*>( this );
+        me->_sortedNodes = me->_nodes;
+        std::sort( me->_sortedNodes.begin(), me->_sortedNodes.end() );
+      }
+      return _sortedNodes;
+    }
+
+    size_t NbSub() const
+    {
+      return _nodes.size();
+    }
+
+    SubBorder Sub(size_t i) const
+    {
+      return SubBorder( _nodes[i], NbSub() > 2 ? _nodes[ (i+1)%NbSub() ] : 0 );
+    }
+
+    void AddSelfTo( TBorderLinks& borderLinks )
+    {
+      _mappedSubs.resize( NbSub() );
+      for ( size_t i = 0; i < NbSub(); ++i )
+      {
+        TBorderLinks::iterator s2b =
+          borderLinks.insert( std::make_pair( Sub(i), TBorderLinks::mapped_type() )).first;
+        s2b->second.push_back( this );
+        _mappedSubs[ i ] = s2b;
+      }
+    }
+
+    void Clear()
+    {
+      _nodes.clear();
+    }
+
+    const SMDS_MeshElement* GetMarkedElem() const
+    {
+      if ( _nodes.empty() ) return 0; // cleared
+      if ( _elems[0] && _elems[0]->isMarked() ) return _elems[0];
+      if ( _elems[1] && _elems[1]->isMarked() ) return _elems[1];
+      return 0;
+    }
+
+    gp_XYZ GetNorm() const // normal to the border
+    {
+      gp_XYZ norm;
+      if ( _nodes.size() == 2 )
+      {
+        gp_XYZ avgNorm( 0,0,0 ); // sum of normals of adjacent faces
+        if ( SMESH_MeshAlgos::FaceNormal( _elems[0], norm ))
+          avgNorm += norm;
+        if ( SMESH_MeshAlgos::FaceNormal( _elems[1], norm ))
+          avgNorm += norm;
+
+        gp_XYZ bordDir( SMESH_NodeXYZ( _nodes[0] ) - SMESH_NodeXYZ( _nodes[1] ));
+        norm = bordDir ^ avgNorm;
+      }
+      else
+      {
+        SMESH_NodeXYZ p0( _nodes[0] );
+        SMESH_NodeXYZ p1( _nodes[1] );
+        SMESH_NodeXYZ p2( _nodes[2] );
+        norm = ( p0 - p1 ) ^ ( p2 - p1 );
+      }
+      if ( isOut( _nodes[0], norm, GetMarkedElem() ))
+        norm.Reverse();
+
+      return norm;
+    }
+
+    void ChooseSide() // mark an _elem located at positive side of fissure
+    {
+      _elems[0]->setIsMarked( true );
+      gp_XYZ norm = GetNorm();
+      double maxX = norm.Coord(1);
+      if ( Abs( maxX ) < Abs( norm.Coord(2)) ) maxX = norm.Coord(2);
+      if ( Abs( maxX ) < Abs( norm.Coord(3)) ) maxX = norm.Coord(3);
+      if ( maxX < 0 )
+      {
+        _elems[0]->setIsMarked( false );
+        _elems[1]->setIsMarked( true );
+      }
+    }
+
+  }; // struct FissureBorder
+
+  //--------------------------------------------------------------------------------
+  /*!
+   * \brief Classifier of elements at fissure edge
+   */
+  class FissureNormal
+  {
+    std::vector< gp_XYZ > _normals;
+    bool                  _bothIn;
+
+  public:
+    void Add( const SMDS_MeshNode* n, const FissureBorder& bord )
+    {
+      _bothIn = false;
+      _normals.reserve(2);
+      _normals.push_back( bord.GetNorm() );
+      if ( _normals.size() == 2 )
+        _bothIn = !isOut( n, _normals[0], bord.GetMarkedElem() );
+    }
+
+    bool IsIn( const SMDS_MeshNode* n, const SMDS_MeshElement* elem ) const
+    {
+      bool isIn = false;
+      switch ( _normals.size() ) {
+      case 1:
+      {
+        isIn = !isOut( n, _normals[0], elem );
+        break;
+      }
+      case 2:
+      {
+        bool in1 = !isOut( n, _normals[0], elem );
+        bool in2 = !isOut( n, _normals[1], elem );
+        isIn = _bothIn ? ( in1 && in2 ) : ( in1 || in2 );
+      }
+      }
+      return isIn;
+    }
+  };
+
+  //================================================================================
+  /*!
+   * \brief Classify an element by a plane passing through a node
+   */
+  //================================================================================
+
+  bool isOut( const SMDS_MeshNode* n, const gp_XYZ& norm, const SMDS_MeshElement* elem )
+  {
+    SMESH_NodeXYZ p = n;
+    double sumDot = 0;
+    for ( int i = 0, nb = elem->NbCornerNodes(); i < nb; ++i )
+    {
+      SMESH_NodeXYZ pi = elem->GetNode( i );
+      sumDot += norm * ( pi - p );
+    }
+    return sumDot < -1e-100;
+  }
+
+  //================================================================================
+  /*!
+   * \brief Find FissureBorder's by nodes to duplicate
+   */
+  //================================================================================
+
+  void findFissureBorders( const TIDSortedElemSet&        theNodes,
+                           std::vector< FissureBorder > & theFissureBorders )
+  {
+    TIDSortedElemSet::const_iterator nIt = theNodes.begin();
+    const SMDS_MeshNode* n = dynamic_cast< const SMDS_MeshNode*>( *nIt );
+    if ( !n ) return;
+    SMDSAbs_ElementType elemType = SMDSAbs_Volume;
+    if ( n->NbInverseElements( elemType ) == 0 )
+    {
+      elemType = SMDSAbs_Face;
+      if ( n->NbInverseElements( elemType ) == 0 )
+        return;
+    }
+    // unmark elements touching the fissure
+    for ( ; nIt != theNodes.end(); ++nIt )
+      SMESH_MeshAlgos::MarkElems( cast2Node(*nIt)->GetInverseElementIterator(), false );
+
+    // loop on elements touching the fissure to get their borders belonging to the fissure
+    std::set< FissureBorder >              fissureBorders;
+    std::vector< const SMDS_MeshElement* > adjElems;
+    std::vector< const SMDS_MeshNode* >    nodes;
+    SMDS_VolumeTool volTool;
+    for ( nIt = theNodes.begin(); nIt != theNodes.end(); ++nIt )
+    {
+      SMDS_ElemIteratorPtr invIt = cast2Node(*nIt)->GetInverseElementIterator( elemType );
+      while ( invIt->more() )
+      {
+        const SMDS_MeshElement* eInv = invIt->next();
+        if ( eInv->isMarked() ) continue;
+        eInv->setIsMarked( true );
+
+        if ( elemType == SMDSAbs_Volume )
+        {
+          volTool.Set( eInv );
+          int iQuad = eInv->IsQuadratic() ? 2 : 1;
+          for ( int iF = 0, nbF = volTool.NbFaces(); iF < nbF; ++iF )
+          {
+            const SMDS_MeshNode** nn = volTool.GetFaceNodes( iF );
+            int                  nbN = volTool.NbFaceNodes( iF ) / iQuad;
+            nodes.clear();
+            bool allOnFissure = true;
+            for ( int iN = 0; iN < nbN  && allOnFissure; iN += iQuad )
+              if (( allOnFissure = theNodes.count( nn[ iN ])))
+                nodes.push_back( nn[ iN ]);
+            if ( allOnFissure )
+              fissureBorders.insert( std::move( FissureBorder( &nodes[0], nodes.size(),
+                                                               elemType, adjElems )));
+          }
+        }
+        else // elemType == SMDSAbs_Face
+        {
+          const SMDS_MeshNode* nn[2] = { eInv->GetNode( eInv->NbCornerNodes()-1 ), 0 };
+          bool            onFissure0 = theNodes.count( nn[0] ), onFissure1;
+          for ( int iN = 0, nbN = eInv->NbCornerNodes(); iN < nbN; ++iN )
+          {
+            nn[1]      = eInv->GetNode( iN );
+            onFissure1 = theNodes.count( nn[1] );
+            if ( onFissure0 && onFissure1 )
+              fissureBorders.insert( std::move( FissureBorder( nn, 2, elemType, adjElems )));
+            nn[0]      = nn[1];
+            onFissure0 = onFissure1;
+          }
+        }
+      }
+    }
+
+    theFissureBorders.reserve( theFissureBorders.size() + fissureBorders.size());
+    std::set< FissureBorder >::iterator bord = fissureBorders.begin();
+    for ( ; bord != fissureBorders.end(); ++bord )
+    {
+      theFissureBorders.push_back( std::move( const_cast<FissureBorder&>( *bord ) ));
+    }
+    return;
+  } // findFissureBorders()
+
+  //================================================================================
+  /*!
+   * \brief Find elements on one side of a fissure defined by elements or nodes to duplicate
+   *  \param [in] theElemsOrNodes - elements or nodes to duplicate
+   *  \param [in] theNodesNot - nodes not to duplicate
+   *  \param [out] theAffectedElems - the found elements
+   */
+  //================================================================================
+
+  void findAffectedElems( const TIDSortedElemSet& theElemsOrNodes,
+                          TIDSortedElemSet&       theAffectedElems)
+  {
+    if ( theElemsOrNodes.empty() ) return;
+
+    // find FissureBorder's
+
+    std::vector< FissureBorder >           fissure;
+    std::vector< const SMDS_MeshElement* > elemsByFacet;
+
+    TIDSortedElemSet::const_iterator elIt = theElemsOrNodes.begin();
+    if ( (*elIt)->GetType() == SMDSAbs_Node )
+    {
+      findFissureBorders( theElemsOrNodes, fissure );
+    }
+    else
+    {
+      fissure.reserve( theElemsOrNodes.size() );
+      for ( ; elIt != theElemsOrNodes.end(); ++elIt )
+        fissure.push_back( std::move( FissureBorder( *elIt, elemsByFacet )));
+    }
+    if ( fissure.empty() )
+      return;
+
+    // fill borderLinks
+
+    TBorderLinks borderLinks;
+
+    for ( size_t i = 0; i < fissure.size(); ++i )
+    {
+      fissure[i].AddSelfTo( borderLinks );
+    }
+
+    // get theAffectedElems
+
+    // unmark elements having nodes on the fissure, theAffectedElems elements will be marked
+    for ( size_t i = 0; i < fissure.size(); ++i )
+      for ( size_t j = 0; j < fissure[i]._nodes.size(); ++j )
+      {
+        SMESH_MeshAlgos::MarkElemNodes( fissure[i]._nodes[j]->GetInverseElementIterator(),
+                                        false, /*markElem=*/true );
+      }
+
+    std::vector<const SMDS_MeshNode *>                 facetNodes;
+    std::map< const SMDS_MeshNode*, FissureNormal >    fissEdgeNodes2Norm;
+    boost::container::flat_set< const SMDS_MeshNode* > fissureNodes;
+
+    // choose a side of fissure
+    fissure[0].ChooseSide();
+    theAffectedElems.insert( fissure[0].GetMarkedElem() );
+
+    size_t nbCheckedBorders = 0;
+    while ( nbCheckedBorders < fissure.size() )
+    {
+      // find a FissureBorder to treat
+      FissureBorder* bord = 0;
+      for ( size_t i = 0; i < fissure.size()  && !bord; ++i )
+        if ( fissure[i].GetMarkedElem() )
+          bord = & fissure[i];
+      for ( size_t i = 0; i < fissure.size()  && !bord; ++i )
+        if ( fissure[i].NbSub() > 0 && fissure[i]._elems[0] )
+        {
+          bord = & fissure[i];
+          bord->ChooseSide();
+          theAffectedElems.insert( bord->GetMarkedElem() );
+        }
+      if ( !bord ) return;
+      ++nbCheckedBorders;
+
+      // treat FissureBorder's linked to bord
+      fissureNodes.clear();
+      fissureNodes.insert( bord->_nodes.begin(), bord->_nodes.end() );
+      for ( size_t i = 0; i < bord->NbSub(); ++i )
+      {
+        TBorderLinks::iterator l2b = bord->_mappedSubs[ i ];
+        if ( l2b == borderLinks.end() || l2b->second.empty() ) continue;
+        std::vector< FissureBorder* >& linkedBorders = l2b->second;
+        const SubBorder&                          sb = l2b->first;
+        const SMDS_MeshElement*             bordElem = bord->GetMarkedElem();
+
+        if ( linkedBorders.size() == 1 ) // fissure edge reached, fill fissEdgeNodes2Norm
+        {
+          for ( int j = 0; j < sb._nbNodes; ++j )
+            fissEdgeNodes2Norm[ sb._nodes[j] ].Add( sb._nodes[j], *bord );
+          continue;
+        }
+
+        // add to theAffectedElems elems sharing nodes of a SubBorder and a node of bordElem
+        // until an elem adjacent to a neighbour FissureBorder is found
+        facetNodes.clear();
+        facetNodes.insert( facetNodes.end(), sb._nodes, sb._nodes + sb._nbNodes );
+        facetNodes.resize( sb._nbNodes + 1 );
+
+        while ( bordElem )
+        {
+          // check if bordElem is adjacent to a neighbour FissureBorder
+          for ( size_t j = 0; j < linkedBorders.size(); ++j )
+          {
+            FissureBorder* bord2 = linkedBorders[j];
+            if ( bord2 == bord ) continue;
+            if ( bordElem == bord2->_elems[0] || bordElem == bord2->_elems[1] )
+              bordElem = 0;
+            else
+              fissureNodes.insert( bord2->_nodes.begin(), bord2->_nodes.end() );
+          }
+          if ( !bordElem )
+            break;
+
+          // find the next bordElem
+          const SMDS_MeshElement* nextBordElem = 0;
+          for ( int iN = 0, nbN = bordElem->NbCornerNodes(); iN < nbN  && !nextBordElem; ++iN )
+          {
+            const SMDS_MeshNode* n = bordElem->GetNode( iN );
+            if ( fissureNodes.count( n )) continue;
+
+            facetNodes[ sb._nbNodes ] = n;
+            elemsByFacet.clear();
+            if ( SMDS_Mesh::GetElementsByNodes( facetNodes, elemsByFacet ) > 1 )
+            {
+              for ( size_t iE = 0; iE < elemsByFacet.size(); ++iE )
+                if ( elemsByFacet[ iE ] != bordElem &&
+                     !elemsByFacet[ iE ]->isMarked() )
+                {
+                  theAffectedElems.insert( elemsByFacet[ iE ]);
+                  elemsByFacet[ iE ]->setIsMarked( true );
+                  if ( elemsByFacet[ iE ]->GetType() == bordElem->GetType() )
+                    nextBordElem = elemsByFacet[ iE ];
+                }
+            }
+          }
+          bordElem = nextBordElem;
+
+        } // while ( bordElem )
+
+        linkedBorders.clear(); // not to treat this link any more
+
+      } // loop on SubBorder's of a FissureBorder
+
+      bord->Clear();
+
+    } // loop on FissureBorder's
+
+
+    // add elements sharing only one node of the fissure, except those sharing fissure edge nodes
+
+    // mark nodes of theAffectedElems
+    SMESH_MeshAlgos::MarkElemNodes( theAffectedElems.begin(), theAffectedElems.end(), true );
+
+    // unmark nodes of the fissure
+    elIt = theElemsOrNodes.begin();
+    if ( (*elIt)->GetType() == SMDSAbs_Node )
+      SMESH_MeshAlgos::MarkElems( elIt, theElemsOrNodes.end(), false );
+    else
+      SMESH_MeshAlgos::MarkElemNodes( elIt, theElemsOrNodes.end(), false );
+
+    std::vector< gp_XYZ > normVec;
+
+    // loop on nodes of the fissure, add elements having marked nodes
+    for ( elIt = theElemsOrNodes.begin(); elIt != theElemsOrNodes.end(); ++elIt )
+    {
+      const SMDS_MeshElement* e = (*elIt);
+      if ( e->GetType() != SMDSAbs_Node )
+        e->setIsMarked( true ); // avoid adding a fissure element
+
+      for ( int iN = 0, nbN = e->NbCornerNodes(); iN < nbN; ++iN )
+      {
+        const SMDS_MeshNode* n = e->GetNode( iN );
+        if ( fissEdgeNodes2Norm.count( n ))
+          continue;
+
+        SMDS_ElemIteratorPtr invIt = n->GetInverseElementIterator();
+        while ( invIt->more() )
+        {
+          const SMDS_MeshElement* eInv = invIt->next();
+          if ( eInv->isMarked() ) continue;
+          eInv->setIsMarked( true );
+
+          SMDS_ElemIteratorPtr nIt = eInv->nodesIterator();
+          while( nIt->more() )
+            if ( nIt->next()->isMarked())
+            {
+              theAffectedElems.insert( eInv );
+              SMESH_MeshAlgos::MarkElems( eInv->nodesIterator(), true );
+              n->setIsMarked( false );
+              break;
+            }
+        }
+      }
+    }
+
+    // add elements on the fissure edge
+    std::map< const SMDS_MeshNode*, FissureNormal >::iterator n2N;
+    for ( n2N = fissEdgeNodes2Norm.begin(); n2N != fissEdgeNodes2Norm.end(); ++n2N )
+    {
+      const SMDS_MeshNode* edgeNode = n2N->first;
+      const FissureNormal & normals = n2N->second;
+
+      SMDS_ElemIteratorPtr invIt = edgeNode->GetInverseElementIterator();
+      while ( invIt->more() )
+      {
+        const SMDS_MeshElement* eInv = invIt->next();
+        if ( eInv->isMarked() ) continue;
+        eInv->setIsMarked( true );
+
+        // classify eInv using normals
+        bool toAdd = normals.IsIn( edgeNode, eInv );
+        if ( toAdd ) // check if all nodes lie on the fissure edge
+        {
+          bool notOnEdge = false;
+          for ( int iN = 0, nbN = eInv->NbCornerNodes(); iN < nbN  && !notOnEdge; ++iN )
+            notOnEdge = !fissEdgeNodes2Norm.count( eInv->GetNode( iN ));
+          toAdd = notOnEdge;
+        }
+        if ( toAdd )
+        {
+          theAffectedElems.insert( eInv );
+        }
+      }
+    }
+
+    return;
+  } // findAffectedElems()
+} // namespace
+
+//================================================================================
+/*!
+ * \brief Create elements equal (on same nodes) to given ones
+ *  \param [in] theElements - a set of elems to duplicate. If it is empty, all
+ *              elements of the uppest dimension are duplicated.
+ */
+//================================================================================
+
+void SMESH_MeshEditor::DoubleElements( const TIDSortedElemSet& theElements )
+{
+  ClearLastCreated();
+  SMESHDS_Mesh* mesh = GetMeshDS();
+
+  // get an element type and an iterator over elements
+
+  SMDSAbs_ElementType type = SMDSAbs_All;
+  SMDS_ElemIteratorPtr elemIt;
+  if ( theElements.empty() )
+  {
+    if ( mesh->NbNodes() == 0 )
+      return;
+    // get most complex type
+    SMDSAbs_ElementType types[SMDSAbs_NbElementTypes] = {
+      SMDSAbs_Volume, SMDSAbs_Face, SMDSAbs_Edge,
+      SMDSAbs_0DElement, SMDSAbs_Ball, SMDSAbs_Node
+    };
+    for ( int i = 0; i < SMDSAbs_NbElementTypes; ++i )
+      if ( mesh->GetMeshInfo().NbElements( types[i] ))
+      {
+        type = types[i];
         break;
       }
-    // put all elements in the vector <allElems>
-    allElems.reserve( mesh->GetMeshInfo().NbElements( type ));
     elemIt = mesh->elementsIterator( type );
-    while ( elemIt->more() )
-      allElems.push_back( elemIt->next());
-    elemIt = elemSetIterator( allElems );
   }
   else
   {
     type = (*theElements.begin())->GetType();
-    elemIt = elemSetIterator( theElements );
+    elemIt = SMESHUtils::elemSetIterator( theElements );
   }
 
+  // un-mark all elements to avoid duplicating just created elements
+  SMESH_MeshAlgos::MarkElems( mesh->elementsIterator( type ), false );
+
   // duplicate elements
 
   ElemFeatures elemType;
@@ -10652,13 +10978,14 @@ void SMESH_MeshEditor::DoubleElements( const TIDSortedElemSet& theElements )
   while ( elemIt->more() )
   {
     const SMDS_MeshElement* elem = elemIt->next();
-    if ( elem->GetType() != type )
+    if ( elem->GetType() != type || elem->isMarked() )
       continue;
 
     elemType.Init( elem, /*basicOnly=*/false );
     nodes.assign( elem->begin_nodes(), elem->end_nodes() );
 
-    AddElement( nodes, elemType );
+    if ( const SMDS_MeshElement* newElem = AddElement( nodes, elemType ))
+      newElem->setIsMarked( true );
   }
 }
 
@@ -10678,8 +11005,7 @@ bool SMESH_MeshEditor::DoubleNodes( const TIDSortedElemSet& theElems,
                                     const TIDSortedElemSet& theNodesNot,
                                     const TIDSortedElemSet& theAffectedElems )
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( theElems.size() == 0 )
     return false;
@@ -10724,8 +11050,8 @@ bool SMESH_MeshEditor::doubleNodes(SMESHDS_Mesh*           theMeshDS,
   for ( ;  elemItr != theElems.end(); ++elemItr )
   {
     const SMDS_MeshElement* anElem = *elemItr;
-    if (!anElem)
-      continue;
+    // if (!anElem)
+    //   continue;
 
     // duplicate nodes to duplicate element
     bool isDuplicate = false;
@@ -10747,7 +11073,7 @@ bool SMESH_MeshEditor::doubleNodes(SMESHDS_Mesh*           theMeshDS,
         aNewNode = theMeshDS->AddNode( aCurrNode->X(), aCurrNode->Y(), aCurrNode->Z() );
         copyPosition( aCurrNode, aNewNode );
         theNodeNodeMap[ aCurrNode ] = aNewNode;
-        myLastCreatedNodes.Append( aNewNode );
+        myLastCreatedNodes.push_back( aNewNode );
       }
       isDuplicate |= (aCurrNode != aNewNode);
       newNodes[ ind++ ] = aNewNode;
@@ -10779,8 +11105,7 @@ bool SMESH_MeshEditor::doubleNodes(SMESHDS_Mesh*           theMeshDS,
 bool SMESH_MeshEditor::DoubleNodes( const std::list< int >& theListOfNodes,
                                     const std::list< int >& theListOfModifiedElems )
 {
-  myLastCreatedElems.Clear();
-  myLastCreatedNodes.Clear();
+  ClearLastCreated();
 
   if ( theListOfNodes.size() == 0 )
     return false;
@@ -10796,8 +11121,7 @@ bool SMESH_MeshEditor::DoubleNodes( const std::list< int >& theListOfNodes,
   std::list< int >::const_iterator aNodeIter;
   for ( aNodeIter = theListOfNodes.begin(); aNodeIter != theListOfNodes.end(); ++aNodeIter )
   {
-    int aCurr = *aNodeIter;
-    SMDS_MeshNode* aNode = (SMDS_MeshNode*)aMeshDS->FindNode( aCurr );
+    const SMDS_MeshNode* aNode = aMeshDS->FindNode( *aNodeIter );
     if ( !aNode )
       continue;
 
@@ -10808,53 +11132,32 @@ bool SMESH_MeshEditor::DoubleNodes( const std::list< int >& theListOfNodes,
     {
       copyPosition( aNode, aNewNode );
       anOldNodeToNewNode[ aNode ] = aNewNode;
-      myLastCreatedNodes.Append( aNewNode );
+      myLastCreatedNodes.push_back( aNewNode );
     }
   }
 
-  // Create map of new nodes for modified elements
+  // Change nodes of elements
 
-  std::map< SMDS_MeshElement*, vector<const SMDS_MeshNode*> > anElemToNodes;
+  std::vector<const SMDS_MeshNode*> aNodeArr;
 
   std::list< int >::const_iterator anElemIter;
-  for ( anElemIter = theListOfModifiedElems.begin();
-        anElemIter != theListOfModifiedElems.end(); ++anElemIter )
+  for ( anElemIter =  theListOfModifiedElems.begin();
+        anElemIter != theListOfModifiedElems.end();
+        anElemIter++ )
   {
-    int aCurr = *anElemIter;
-    SMDS_MeshElement* anElem = (SMDS_MeshElement*)aMeshDS->FindElement( aCurr );
+    const SMDS_MeshElement* anElem = aMeshDS->FindElement( *anElemIter );
     if ( !anElem )
       continue;
 
-    vector<const SMDS_MeshNode*> aNodeArr( anElem->NbNodes() );
-
-    SMDS_ElemIteratorPtr anIter = anElem->nodesIterator();
-    int ind = 0;
-    while ( anIter->more() )
-    {
-      SMDS_MeshNode* aCurrNode = (SMDS_MeshNode*)anIter->next();
-      if ( aCurr && anOldNodeToNewNode.find( aCurrNode ) != anOldNodeToNewNode.end() )
-      {
-        const SMDS_MeshNode* aNewNode = anOldNodeToNewNode[ aCurrNode ];
-        aNodeArr[ ind++ ] = aNewNode;
-      }
-      else
-        aNodeArr[ ind++ ] = aCurrNode;
-    }
-    anElemToNodes[ anElem ] = aNodeArr;
-  }
-
-  // Change nodes of elements
-
-  std::map< SMDS_MeshElement*, vector<const SMDS_MeshNode*> >::iterator
-    anElemToNodesIter = anElemToNodes.begin();
-  for ( ; anElemToNodesIter != anElemToNodes.end(); ++anElemToNodesIter )
-  {
-    const SMDS_MeshElement* anElem = anElemToNodesIter->first;
-    vector<const SMDS_MeshNode*> aNodeArr = anElemToNodesIter->second;
-    if ( anElem )
+    aNodeArr.assign( anElem->begin_nodes(), anElem->end_nodes() );
+    for( size_t i = 0; i < aNodeArr.size(); ++i )
     {
-      aMeshDS->ChangeElementNodes( anElem, &aNodeArr[ 0 ], anElem->NbNodes() );
+      std::map< const SMDS_MeshNode*, const SMDS_MeshNode* >::iterator n2n =
+        anOldNodeToNewNode.find( aNodeArr[ i ]);
+      if ( n2n != anOldNodeToNewNode.end() )
+        aNodeArr[ i ] = n2n->second;
     }
+    aMeshDS->ChangeElementNodes( anElem, &aNodeArr[ 0 ], aNodeArr.size() );
   }
 
   return true;
@@ -10864,8 +11167,8 @@ namespace {
 
   //================================================================================
   /*!
-  \brief Check if element located inside shape
-  \return TRUE if IN or ON shape, FALSE otherwise
+    \brief Check if element located inside shape
+    \return TRUE if IN or ON shape, FALSE otherwise
   */
   //================================================================================
 
@@ -10876,8 +11179,8 @@ namespace {
   {
     gp_XYZ centerXYZ (0, 0, 0);
     SMDS_ElemIteratorPtr aNodeItr = theElem->nodesIterator();
-    while (aNodeItr->more())
-      centerXYZ += SMESH_TNodeXYZ(cast2Node( aNodeItr->next()));
+    while ( aNodeItr->more() )
+      centerXYZ += SMESH_NodeXYZ( aNodeItr->next() );
 
     gp_Pnt aPnt = centerXYZ / theElem->NbNodes();
     theClassifier.Perform(aPnt, theTol);
@@ -10932,9 +11235,9 @@ namespace {
          (select elements with a gravity center on the side given by faces normals).
          This mode (null shape) is faster, but works only when theElems are faces, with coherents orientations.
          The replicated nodes should be associated to affected elements.
-  \return groups of affected elements
+  \return true
   \sa DoubleNodeElemGroupsInRegion()
- */
+*/
 //================================================================================
 
 bool SMESH_MeshEditor::AffectedElemGroupsInRegion( const TIDSortedElemSet& theElems,
@@ -10944,94 +11247,7 @@ bool SMESH_MeshEditor::AffectedElemGroupsInRegion( const TIDSortedElemSet& theEl
 {
   if ( theShape.IsNull() )
   {
-    std::set<const SMDS_MeshNode*> alreadyCheckedNodes;
-    std::set<const SMDS_MeshElement*> alreadyCheckedElems;
-    std::set<const SMDS_MeshElement*> edgesToCheck;
-    alreadyCheckedNodes.clear();
-    alreadyCheckedElems.clear();
-    edgesToCheck.clear();
-
-    // --- iterates on elements to be replicated and get elements by back references from their nodes
-
-    TIDSortedElemSet::const_iterator elemItr = theElems.begin();
-    for ( ;  elemItr != theElems.end(); ++elemItr )
-    {
-      SMDS_MeshElement* anElem = (SMDS_MeshElement*)*elemItr;
-      if (!anElem || (anElem->GetType() != SMDSAbs_Face))
-        continue;
-      gp_XYZ normal;
-      SMESH_MeshAlgos::FaceNormal( anElem, normal, /*normalized=*/true );
-      std::set<const SMDS_MeshNode*> nodesElem;
-      nodesElem.clear();
-      SMDS_ElemIteratorPtr nodeItr = anElem->nodesIterator();
-      while ( nodeItr->more() )
-      {
-        const SMDS_MeshNode* aNode = cast2Node(nodeItr->next());
-        nodesElem.insert(aNode);
-      }
-      std::set<const SMDS_MeshNode*>::iterator nodit = nodesElem.begin();
-      for (; nodit != nodesElem.end(); nodit++)
-      {
-        const SMDS_MeshNode* aNode = *nodit;
-        if ( !aNode || theNodesNot.find(aNode) != theNodesNot.end() )
-          continue;
-        if (alreadyCheckedNodes.find(aNode) != alreadyCheckedNodes.end())
-          continue;
-        alreadyCheckedNodes.insert(aNode);
-        SMDS_ElemIteratorPtr backElemItr = aNode->GetInverseElementIterator();
-        while ( backElemItr->more() )
-        {
-          const SMDS_MeshElement* curElem = backElemItr->next();
-          if (alreadyCheckedElems.find(curElem) != alreadyCheckedElems.end())
-            continue;
-          if (theElems.find(curElem) != theElems.end())
-            continue;
-          alreadyCheckedElems.insert(curElem);
-          double x=0, y=0, z=0;
-          int nb = 0;
-          SMDS_ElemIteratorPtr nodeItr2 = curElem->nodesIterator();
-          while ( nodeItr2->more() )
-          {
-            const SMDS_MeshNode* anotherNode = cast2Node(nodeItr2->next());
-            x += anotherNode->X();
-            y += anotherNode->Y();
-            z += anotherNode->Z();
-            nb++;
-          }
-          gp_XYZ p;
-          p.SetCoord( x/nb -aNode->X(),
-                      y/nb -aNode->Y(),
-                      z/nb -aNode->Z() );
-          if (normal*p > 0)
-          {
-            theAffectedElems.insert( curElem );
-          }
-          else if (curElem->GetType() == SMDSAbs_Edge)
-            edgesToCheck.insert(curElem);
-        }
-      }
-    }
-    // --- add also edges lying on the set of faces (all nodes in alreadyCheckedNodes)
-    std::set<const SMDS_MeshElement*>::iterator eit = edgesToCheck.begin();
-    for( ; eit != edgesToCheck.end(); eit++)
-    {
-      bool onside = true;
-      const SMDS_MeshElement* anEdge = *eit;
-      SMDS_ElemIteratorPtr nodeItr = anEdge->nodesIterator();
-      while ( nodeItr->more() )
-      {
-        const SMDS_MeshNode* aNode = cast2Node(nodeItr->next());
-        if (alreadyCheckedNodes.find(aNode) == alreadyCheckedNodes.end())
-        {
-          onside = false;
-          break;
-        }
-      }
-      if (onside)
-      {
-        theAffectedElems.insert(anEdge);
-      }
-    }
+    findAffectedElems( theElems, theAffectedElems );
   }
   else
   {
@@ -11052,9 +11268,7 @@ bool SMESH_MeshEditor::AffectedElemGroupsInRegion( const TIDSortedElemSet& theEl
     TIDSortedElemSet::const_iterator elemItr = theElems.begin();
     for ( ;  elemItr != theElems.end(); ++elemItr )
     {
-      SMDS_MeshElement* anElem = (SMDS_MeshElement*)*elemItr;
-      if (!anElem)
-        continue;
+      SMDS_MeshElement*     anElem = (SMDS_MeshElement*)*elemItr;
       SMDS_ElemIteratorPtr nodeItr = anElem->nodesIterator();
       while ( nodeItr->more() )
       {
@@ -11066,9 +11280,9 @@ bool SMESH_MeshEditor::AffectedElemGroupsInRegion( const TIDSortedElemSet& theEl
         {
           const SMDS_MeshElement* curElem = backElemItr->next();
           if ( curElem && theElems.find(curElem) == theElems.end() &&
-              ( bsc3d.get() ?
-                isInside( curElem, *bsc3d, aTol ) :
-                isInside( curElem, *aFaceClassifier, aTol )))
+               ( bsc3d.get() ?
+                 isInside( curElem, *bsc3d, aTol ) :
+                 isInside( curElem, *aFaceClassifier, aTol )))
             theAffectedElems.insert( curElem );
         }
       }
@@ -12587,7 +12801,7 @@ int SMESH_MeshEditor::MakeBoundaryMesh(const TIDSortedElemSet& elements,
 
   SMDS_ElemIteratorPtr eIt;
   if (elements.empty()) eIt = aMesh->elementsIterator(elemType);
-  else                  eIt = elemSetIterator( elements );
+  else                  eIt = SMESHUtils::elemSetIterator( elements );
 
   while (eIt->more())
   {
@@ -12766,7 +12980,7 @@ int SMESH_MeshEditor::MakeBoundaryMesh(const TIDSortedElemSet& elements,
     else // store present elements to add them to a group
       for ( size_t i = 0 ; i < presentBndElems.size(); ++i )
       {
-        presentEditor->myLastCreatedElems.Append( presentBndElems[ i ]);
+        presentEditor->myLastCreatedElems.push_back( presentBndElems[ i ]);
       }
 
   } // loop on given elements
@@ -12777,11 +12991,11 @@ int SMESH_MeshEditor::MakeBoundaryMesh(const TIDSortedElemSet& elements,
   if ( group )
   {
     if ( SMESHDS_Group* g = dynamic_cast<SMESHDS_Group*>( group->GetGroupDS() ))
-      for ( int i = 0; i < tgtEditor.myLastCreatedElems.Size(); ++i )
-        g->SMDSGroup().Add( tgtEditor.myLastCreatedElems( i+1 ));
+      for ( size_t i = 0; i < tgtEditor.myLastCreatedElems.size(); ++i )
+        g->SMDSGroup().Add( tgtEditor.myLastCreatedElems[ i ]);
   }
-  tgtEditor.myLastCreatedElems.Clear();
-  tgtEditor2.myLastCreatedElems.Clear();
+  tgtEditor.myLastCreatedElems.clear();
+  tgtEditor2.myLastCreatedElems.clear();
 
   // -----------------------
   // 5. Copy given elements
@@ -12789,7 +13003,7 @@ int SMESH_MeshEditor::MakeBoundaryMesh(const TIDSortedElemSet& elements,
   if ( toCopyElements && targetMesh != myMesh )
   {
     if (elements.empty()) eIt = aMesh->elementsIterator(elemType);
-    else                  eIt = elemSetIterator( elements );
+    else                  eIt = SMESHUtils::elemSetIterator( elements );
     while (eIt->more())
     {
       const SMDS_MeshElement* elem = eIt->next();
@@ -12798,7 +13012,7 @@ int SMESH_MeshEditor::MakeBoundaryMesh(const TIDSortedElemSet& elements,
         tgtNodes[inode] = getNodeWithSameID( tgtMeshDS, elem->GetNode(inode) );
       tgtEditor.AddElement( tgtNodes, elemToCopy.Init( elem ));
 
-      tgtEditor.myLastCreatedElems.Clear();
+      tgtEditor.myLastCreatedElems.clear();
     }
   }
   return nbAddedBnd;
@@ -12845,3 +13059,482 @@ void SMESH_MeshEditor::copyPosition( const SMDS_MeshNode* from,
   default:;
   }
 }
+
+namespace // utils for MakePolyLine
+{
+  //================================================================================
+  /*!
+   * \brief Sequence of found points and a current point data
+   */
+  struct Path
+  {
+    std::vector< gp_XYZ >   myPoints;
+    double                  myLength;
+
+    int                     mySrcPntInd; //!< start point index
+    const SMDS_MeshElement* myFace;
+    SMESH_NodeXYZ           myNode1;
+    SMESH_NodeXYZ           myNode2;
+    int                     myNodeInd1;
+    int                     myNodeInd2;
+    double                  myDot1;
+    double                  myDot2;
+    TIDSortedElemSet        myElemSet, myAvoidSet;
+
+    Path(): myLength(0.0), myFace(0) {}
+
+    bool SetCutAtCorner( const SMESH_NodeXYZ&    cornerNode,
+                         const SMDS_MeshElement* face,
+                         const gp_XYZ&           plnNorm,
+                         const gp_XYZ&           plnOrig );
+
+    void AddPoint( const gp_XYZ& p );
+
+    bool Extend( const gp_XYZ& plnNorm, const gp_XYZ& plnOrig );
+
+    bool ReachSamePoint( const Path& other );
+
+    static void Remove( std::vector< Path > & paths, size_t& i );
+  };
+
+  //================================================================================
+  /*!
+   * \brief Return true if this Path meats another
+   */
+  //================================================================================
+
+  bool Path::ReachSamePoint( const Path& other )
+  {
+    return ( mySrcPntInd != other.mySrcPntInd &&
+             myFace == other.myFace );
+  }
+
+  //================================================================================
+  /*!
+   * \brief Remove a path from a vector
+   */
+  //================================================================================
+
+  void Path::Remove( std::vector< Path > & paths, size_t& i )
+  {
+    if ( paths.size() > 1 )
+    {
+      size_t j = paths.size() - 1; // last item to be removed
+      if ( i < j )
+      {
+        paths[ i ].myPoints.swap( paths[ j ].myPoints );
+        paths[ i ].myLength    = paths[ j ].myLength;
+        paths[ i ].mySrcPntInd = paths[ j ].mySrcPntInd;
+        paths[ i ].myFace      = paths[ j ].myFace;
+        paths[ i ].myNode1     = paths[ j ].myNode1;
+        paths[ i ].myNode2     = paths[ j ].myNode2;
+        paths[ i ].myNodeInd1  = paths[ j ].myNodeInd1;
+        paths[ i ].myNodeInd2  = paths[ j ].myNodeInd2;
+        paths[ i ].myDot1      = paths[ j ].myDot1;
+        paths[ i ].myDot2      = paths[ j ].myDot2;
+      }
+    }
+    paths.pop_back();
+    if ( i > 0 )
+      --i;
+  }
+
+  //================================================================================
+  /*!
+   * \brief Store a point that is at a node of a face if the face is intersected by plane.
+   *        Return false if the node is a sole intersection point of the face and the plane
+   */
+  //================================================================================
+
+  bool Path::SetCutAtCorner( const SMESH_NodeXYZ&    cornerNode,
+                             const SMDS_MeshElement* face,
+                             const gp_XYZ&           plnNorm,
+                             const gp_XYZ&           plnOrig )
+  {
+    if ( face == myFace )
+      return false;
+    myNodeInd1 = face->GetNodeIndex( cornerNode._node );
+    myNodeInd2 = ( myNodeInd1 + 1 ) % face->NbCornerNodes();
+    int   ind3 = ( myNodeInd1 + 2 ) % face->NbCornerNodes();
+    myNode1.Set( face->GetNode( ind3 ));
+    myNode2.Set( face->GetNode( myNodeInd2 ));
+
+    myDot1 = plnNorm * ( myNode1 - plnOrig );
+    myDot2 = plnNorm * ( myNode2 - plnOrig );
+
+    bool ok = ( myDot1 * myDot2 < 0 );
+    if ( !ok && myDot1 * myDot2 == 0 )
+    {
+      ok = ( myDot1 != myDot2 );
+      if ( ok && myFace )
+        ok = ( myFace->GetNodeIndex(( myDot1 == 0 ? myNode1 : myNode2 )._node ) < 0 );
+    }
+    if ( ok )
+    {
+      myFace = face;
+      myDot1 = 0;
+      AddPoint( cornerNode );
+    }
+    return ok;
+  }
+
+  //================================================================================
+  /*!
+   * \brief Store a point and update myLength
+   */
+  //================================================================================
+
+  void Path::AddPoint( const gp_XYZ& p )
+  {
+    if ( !myPoints.empty() )
+      myLength += ( p - myPoints.back() ).Modulus();
+    else
+      myLength = 0;
+    myPoints.push_back( p );
+  }
+
+  //================================================================================
+  /*!
+   * \brief Try to find the next point
+   *  \param [in] plnNorm - cutting plane normal
+   *  \param [in] plnOrig - cutting plane origin
+   */
+  //================================================================================
+
+  bool Path::Extend( const gp_XYZ& plnNorm, const gp_XYZ& plnOrig )
+  {
+    int nodeInd3 = ( myNodeInd1 + 1 ) % myFace->NbCornerNodes();
+    if ( myNodeInd2 == nodeInd3 )
+      nodeInd3 = ( myNodeInd1 + 2 ) % myFace->NbCornerNodes();
+
+    SMESH_NodeXYZ node3 = myFace->GetNode( nodeInd3 );
+    double         dot3 = plnNorm * ( node3 - plnOrig );
+
+    if ( dot3 * myDot1 < 0. )
+    {
+      myNode2    = node3;
+      myNodeInd2 = nodeInd3;
+      myDot2     = dot3;
+    }
+    else if ( dot3 * myDot2 < 0. )
+    {
+      myNode1    = node3;
+      myNodeInd1 = nodeInd3;
+      myDot1     = dot3;
+    }
+    else if ( dot3 == 0. )
+    {
+      SMDS_ElemIteratorPtr fIt = node3._node->GetInverseElementIterator(SMDSAbs_Face);
+      while ( fIt->more() )
+        if ( SetCutAtCorner( node3, fIt->next(), plnNorm, plnOrig ))
+          return true;
+      return false;
+    }
+    else if ( myDot2 == 0. )
+    {
+      SMESH_NodeXYZ node2 = myNode2; // copy as myNode2 changes in SetCutAtCorner()
+      SMDS_ElemIteratorPtr fIt = node2._node->GetInverseElementIterator(SMDSAbs_Face);
+      while ( fIt->more() )
+        if ( SetCutAtCorner( node2, fIt->next(), plnNorm, plnOrig ))
+          return true;
+      return false;
+    }
+
+    double r = Abs( myDot1 / ( myDot2 - myDot1 ));
+    AddPoint( myNode1 * ( 1 - r ) + myNode2 * r );
+
+    myAvoidSet.clear();
+    myAvoidSet.insert( myFace );
+    myFace = SMESH_MeshAlgos::FindFaceInSet( myNode1._node, myNode2._node,
+                                             myElemSet,   myAvoidSet,
+                                             &myNodeInd1, &myNodeInd2 );
+    return myFace;
+  }
+
+  //================================================================================
+  /*!
+   * \brief Compute a path between two points of PolySegment
+   */
+  struct PolyPathCompute
+  {
+    SMESH_MeshEditor::TListOfPolySegments& mySegments; //!< inout PolySegment's
+    std::vector< Path >&                   myPaths;    //!< path of each of segments to compute
+    SMESH_Mesh*                            myMesh;
+    mutable std::vector< std::string >     myErrors;
+
+    PolyPathCompute( SMESH_MeshEditor::TListOfPolySegments& theSegments,
+                     std::vector< Path >&                   thePaths,
+                     SMESH_Mesh*                            theMesh):
+      mySegments( theSegments ),
+      myPaths( thePaths ),
+      myMesh( theMesh ),
+      myErrors( theSegments.size() )
+    {
+    }
+#undef SMESH_CAUGHT
+#define SMESH_CAUGHT myErrors[i] =
+    void operator() ( const int i ) const
+    {
+      SMESH_TRY;
+      const_cast< PolyPathCompute* >( this )->Compute( i );
+      SMESH_CATCH( SMESH::returnError );
+    }
+#undef SMESH_CAUGHT
+    //================================================================================
+    /*!
+     * \brief Compute a path of a given segment
+     */
+    //================================================================================
+
+    void Compute( const int iSeg )
+    {
+      SMESH_MeshEditor::PolySegment& polySeg = mySegments[ iSeg ];
+
+      // get a cutting plane
+
+      gp_XYZ p1 = SMESH_NodeXYZ( polySeg.myNode1[0] );
+      gp_XYZ p2 = SMESH_NodeXYZ( polySeg.myNode1[1] );
+      if ( polySeg.myNode2[0] ) p1 = 0.5 * ( p1 + SMESH_NodeXYZ( polySeg.myNode2[0] ));
+      if ( polySeg.myNode2[1] ) p2 = 0.5 * ( p2 + SMESH_NodeXYZ( polySeg.myNode2[1] ));
+
+      gp_XYZ plnNorm = ( p1 - p2 ) ^ polySeg.myVector.XYZ();
+      gp_XYZ plnOrig = p2;
+
+      // find paths connecting the 2 end points of polySeg
+
+      std::vector< Path > paths; paths.reserve(10);
+
+      // initialize paths
+
+      for ( int iP = 0; iP < 2; ++iP ) // loop on the polySeg end points
+      {
+        Path path;
+        path.mySrcPntInd = iP;
+        size_t nbPaths = paths.size();
+
+        if ( polySeg.myNode2[ iP ] && polySeg.myNode2[ iP ] != polySeg.myNode1[ iP ] )
+        {
+          while (( path.myFace = SMESH_MeshAlgos::FindFaceInSet( polySeg.myNode1[ iP ],
+                                                                 polySeg.myNode2[ iP ],
+                                                                 path.myElemSet,
+                                                                 path.myAvoidSet,
+                                                                 &path.myNodeInd1,
+                                                                 &path.myNodeInd2 )))
+          {
+            path.myNode1.Set( polySeg.myNode1[ iP ]);
+            path.myNode2.Set( polySeg.myNode2[ iP ]);
+            path.myDot1 = plnNorm * ( path.myNode1 - plnOrig );
+            path.myDot2 = plnNorm * ( path.myNode2 - plnOrig );
+            path.myPoints.clear();
+            path.AddPoint( 0.5 * ( path.myNode1 + path.myNode2 ));
+            path.myAvoidSet.insert( path.myFace );
+            paths.push_back( path );
+          }
+          if ( nbPaths == paths.size() )
+            throw SALOME_Exception ( SMESH_Comment("No face edge found by point ") << iP+1
+                                     << " in a PolySegment " << iSeg );
+        }
+        else // an end point is at node
+        {
+          std::set<const SMDS_MeshNode* > nodes;
+          SMDS_ElemIteratorPtr fIt = polySeg.myNode1[ iP ]->GetInverseElementIterator(SMDSAbs_Face);
+          while ( fIt->more() )
+          {
+            path.myPoints.clear();
+            if ( path.SetCutAtCorner( polySeg.myNode1[ iP ], fIt->next(), plnNorm, plnOrig ))
+            {
+              if (( path.myDot1 * path.myDot2 != 0 ) ||
+                  ( nodes.insert( path.myDot1 == 0 ? path.myNode1._node : path.myNode2._node ).second ))
+                paths.push_back( path );
+            }
+          }
+        }
+
+        // look for a one-segment path
+        for ( size_t i = 0; i < nbPaths; ++i )
+          for ( size_t j = nbPaths; j < paths.size(); ++j )
+            if ( paths[i].myFace == paths[j].myFace )
+            {
+              myPaths[ iSeg ].myPoints.push_back( paths[i].myPoints[0] );
+              myPaths[ iSeg ].myPoints.push_back( paths[j].myPoints[0] );
+              paths.clear();
+            }
+      }
+
+      // extend paths
+
+      myPaths[ iSeg ].myLength = 1e100;
+
+      while ( paths.size() >= 2 )
+      {
+        for ( size_t i = 0; i < paths.size(); ++i )
+        {
+          Path& path = paths[ i ];
+          if ( !path.Extend( plnNorm, plnOrig ) ||         // path reached a mesh boundary
+               path.myLength > myPaths[ iSeg ].myLength ) // path is longer than others
+          {
+            Path::Remove( paths, i );
+            continue;
+          }
+
+          // join paths that reach same point
+          for ( size_t j = 0; j < paths.size(); ++j )
+          {
+            if ( i != j && paths[i].ReachSamePoint( paths[j] ))
+            {
+              double   distLast = ( paths[i].myPoints.back() - paths[j].myPoints.back() ).Modulus();
+              double fullLength = ( paths[i].myLength + paths[j].myLength + distLast );
+              if ( fullLength < myPaths[ iSeg ].myLength )
+              {
+                myPaths[ iSeg ].myLength = fullLength;
+                std::vector< gp_XYZ > & allPoints = myPaths[ iSeg ].myPoints;
+                allPoints.swap( paths[i].myPoints );
+                allPoints.insert( allPoints.end(),
+                                  paths[j].myPoints.rbegin(),
+                                  paths[j].myPoints.rend() );
+              }
+              Path::Remove( paths, i );
+              Path::Remove( paths, j );
+            }
+          }
+        }
+        if ( !paths.empty() && (int) paths[0].myPoints.size() > myMesh->NbFaces() )
+          throw SALOME_Exception(LOCALIZED( "Infinite loop in MakePolyLine()"));
+      }
+
+      if ( myPaths[ iSeg ].myPoints.empty() )
+        throw SALOME_Exception( SMESH_Comment("Can't find a full path for PolySegment #") << iSeg );
+
+    } // PolyPathCompute::Compute()
+
+  }; // struct PolyPathCompute
+
+} // namespace
+
+//=======================================================================
+//function : MakePolyLine
+//purpose  : Create a polyline consisting of 1D mesh elements each lying on a 2D element of
+//           the initial mesh
+//=======================================================================
+
+void SMESH_MeshEditor::MakePolyLine( TListOfPolySegments&   theSegments,
+                                     SMESHDS_Group*         theGroup,
+                                     SMESH_ElementSearcher* theSearcher)
+{
+  std::vector< Path > segPaths( theSegments.size() ); // path of each of segments
+
+  SMESH_ElementSearcher* searcher = theSearcher;
+  SMESHUtils::Deleter<SMESH_ElementSearcher> delSearcher;
+  if ( !searcher )
+  {
+    searcher = SMESH_MeshAlgos::GetElementSearcher( *GetMeshDS() );
+    delSearcher._obj = searcher;
+  }
+
+  // get cutting planes
+
+  std::vector< bool > isVectorOK( theSegments.size(), true );
+  const double planarCoef = 0.333; // plane height in planar case
+
+  for ( size_t iSeg = 0; iSeg < theSegments.size(); ++iSeg )
+  {
+    PolySegment& polySeg = theSegments[ iSeg ];
+
+    gp_XYZ p1 = SMESH_NodeXYZ( polySeg.myNode1[0] );
+    gp_XYZ p2 = SMESH_NodeXYZ( polySeg.myNode1[1] );
+    if ( polySeg.myNode2[0] ) p1 = 0.5 * ( p1 + SMESH_NodeXYZ( polySeg.myNode2[0] ));
+    if ( polySeg.myNode2[1] ) p2 = 0.5 * ( p2 + SMESH_NodeXYZ( polySeg.myNode2[1] ));
+
+    gp_XYZ plnNorm = ( p1 - p2 ) ^ polySeg.myVector.XYZ();
+
+    isVectorOK[ iSeg ] = ( plnNorm.Modulus() > std::numeric_limits<double>::min() );
+    if ( !isVectorOK[ iSeg ])
+    {
+      gp_XYZ pMid = 0.5 * ( p1 + p2 );
+      const SMDS_MeshElement* face;
+      polySeg.myMidProjPoint = searcher->Project( pMid, SMDSAbs_Face, &face );
+      polySeg.myVector       = polySeg.myMidProjPoint.XYZ() - pMid;
+
+      gp_XYZ faceNorm;
+      SMESH_MeshAlgos::FaceNormal( face, faceNorm );
+
+      if ( polySeg.myVector.Magnitude() < Precision::Confusion() ||
+           polySeg.myVector * faceNorm  < Precision::Confusion() )
+      {
+        polySeg.myVector = faceNorm;
+        polySeg.myMidProjPoint = pMid + faceNorm * ( p1 - p2 ).Modulus() * planarCoef;
+      }
+    }
+    else
+    {
+      polySeg.myVector = plnNorm ^ ( p1 - p2 );
+    }
+  }
+
+  // assure that inverse elements are constructed, avoid their concurrent building in threads
+  GetMeshDS()->nodesIterator()->next()->NbInverseElements();
+
+  // find paths
+
+  PolyPathCompute algo( theSegments, segPaths, myMesh );
+  OSD_Parallel::For( 0, theSegments.size(), algo, theSegments.size() == 1 );
+
+  for ( size_t iSeg = 0; iSeg < theSegments.size(); ++iSeg )
+    if ( !algo.myErrors[ iSeg ].empty() )
+      throw SALOME_Exception( algo.myErrors[ iSeg ].c_str() );
+
+  // create an 1D mesh
+
+  const SMDS_MeshNode *n, *nPrev = 0;
+  SMESHDS_Mesh* mesh = GetMeshDS();
+
+  for ( size_t iSeg = 0; iSeg < theSegments.size(); ++iSeg )
+  {
+    const Path& path = segPaths[iSeg];
+    if ( path.myPoints.size() < 2 )
+      continue;
+
+    double tol = path.myLength / path.myPoints.size() / 1000.;
+    if ( !nPrev || ( SMESH_NodeXYZ( nPrev ) - path.myPoints[0] ).SquareModulus() > tol*tol )
+    {
+      nPrev = mesh->AddNode( path.myPoints[0].X(), path.myPoints[0].Y(), path.myPoints[0].Z() );
+      myLastCreatedNodes.push_back( nPrev );
+    }
+    for ( size_t iP = 1; iP < path.myPoints.size(); ++iP )
+    {
+      n = mesh->AddNode( path.myPoints[iP].X(), path.myPoints[iP].Y(), path.myPoints[iP].Z() );
+      myLastCreatedNodes.push_back( n );
+
+      const SMDS_MeshElement* elem = mesh->AddEdge( nPrev, n );
+      myLastCreatedElems.push_back( elem );
+      if ( theGroup )
+        theGroup->Add( elem );
+
+      nPrev = n;
+    }
+
+    // return a vector
+
+    gp_XYZ pMid = 0.5 * ( path.myPoints[0] + path.myPoints.back() );
+    if ( isVectorOK[ iSeg ])
+    {
+      // find the most distance point of a path
+      double maxDist = 0;
+      for ( size_t iP = 1; iP < path.myPoints.size(); ++iP )
+      {
+        double dist = Abs( theSegments[iSeg].myVector * ( path.myPoints[iP] - path.myPoints[0] ));
+        if ( dist > maxDist )
+        {
+          maxDist = dist;
+          theSegments[iSeg].myMidProjPoint = path.myPoints[iP];
+        }
+      }
+      if ( maxDist < Precision::Confusion() ) // planar case
+        theSegments[iSeg].myMidProjPoint =
+          pMid + theSegments[iSeg].myVector.XYZ().Normalized() * path.myLength * planarCoef;
+    }
+    theSegments[iSeg].myVector = gp_Vec( pMid, theSegments[iSeg].myMidProjPoint );
+  }
+
+  return;
+}