Salome HOME
54355: 'Compute' button is absent for 'Number of the double nodes' value in 'Mesh...
[modules/smesh.git] / src / StdMeshers / StdMeshers_QuadFromMedialAxis_1D2D.cxx
index ea8fdc9361b7e15f39a74b206cb050c80e03def4..0b9005bcaa07fadefbd9c679a0774c0900a7bf3c 100644 (file)
@@ -1,4 +1,4 @@
-// Copyright (C) 2007-2015  CEA/DEN, EDF R&D, OPEN CASCADE
+// Copyright (C) 2007-2016  CEA/DEN, EDF R&D, OPEN CASCADE
 //
 // Copyright (C) 2003-2007  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
 // CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
@@ -25,6 +25,7 @@
 
 #include "StdMeshers_QuadFromMedialAxis_1D2D.hxx"
 
+#include "SMESHDS_Mesh.hxx"
 #include "SMESH_Block.hxx"
 #include "SMESH_Gen.hxx"
 #include "SMESH_MAT2d.hxx"
 #include "SMESH_MesherHelper.hxx"
 #include "SMESH_ProxyMesh.hxx"
 #include "SMESH_subMesh.hxx"
+#include "SMESH_subMeshEventListener.hxx"
 #include "StdMeshers_FaceSide.hxx"
+#include "StdMeshers_LayerDistribution.hxx"
+#include "StdMeshers_NumberOfLayers.hxx"
 #include "StdMeshers_Regular_1D.hxx"
 #include "StdMeshers_ViscousLayers2D.hxx"
 
+#include <BRepAdaptor_Curve.hxx>
 #include <BRepBuilderAPI_MakeEdge.hxx>
 #include <BRepTools.hxx>
 #include <BRep_Tool.hxx>
@@ -45,6 +50,7 @@
 #include <Precision.hxx>
 #include <TColgp_HArray1OfPnt.hxx>
 #include <TopExp.hxx>
+#include <TopExp_Explorer.hxx>
 #include <TopLoc_Location.hxx>
 #include <TopTools_MapOfShape.hxx>
 #include <TopoDS.hxx>
@@ -56,6 +62,8 @@
 #include <list>
 #include <vector>
 
+using namespace std;
+
 //================================================================================
 /*!
  * \brief 1D algo
 class StdMeshers_QuadFromMedialAxis_1D2D::Algo1D : public StdMeshers_Regular_1D
 {
 public:
-  Algo1D(int studyId, SMESH_Gen* gen):
-    StdMeshers_Regular_1D( gen->GetANewId(), studyId, gen )
+  Algo1D(SMESH_Gen* gen):
+    StdMeshers_Regular_1D( gen->GetANewId(), gen )
   {
   }
   void SetSegmentLength( double len )
   {
+    SMESH_Algo::_usedHypList.clear();
     _value[ BEG_LENGTH_IND ] = len;
     _value[ PRECISION_IND  ] = 1e-7;
     _hypType = LOCAL_LENGTH;
   }
+  void SetRadialDistribution( const SMESHDS_Hypothesis* hyp )
+  {
+    SMESH_Algo::_usedHypList.clear();
+    if ( !hyp )
+      return;
+
+    if ( const StdMeshers_NumberOfLayers* nl =
+         dynamic_cast< const StdMeshers_NumberOfLayers* >( hyp ))
+    {
+      _ivalue[ NB_SEGMENTS_IND  ] = nl->GetNumberOfLayers();
+      _ivalue[ DISTR_TYPE_IND ]   = 0;
+      _hypType = NB_SEGMENTS;
+    }
+    if ( const StdMeshers_LayerDistribution* ld =
+         dynamic_cast< const StdMeshers_LayerDistribution* >( hyp ))
+    {
+      if ( SMESH_Hypothesis* h = ld->GetLayerDistribution() )
+      {
+        SMESH_Algo::_usedHypList.clear();
+        SMESH_Algo::_usedHypList.push_back( h );
+      }
+    }
+  }
+  void ComputeDistribution(SMESH_MesherHelper& theHelper,
+                           const gp_Pnt&       thePnt1,
+                           const gp_Pnt&       thePnt2,
+                           list< double >&     theParams)
+  {
+    SMESH_Mesh& mesh = *theHelper.GetMesh();
+    TopoDS_Edge edge = BRepBuilderAPI_MakeEdge( thePnt1, thePnt2 );
+
+    SMESH_Hypothesis::Hypothesis_Status aStatus;
+    CheckHypothesis( mesh, edge, aStatus );
+
+    theParams.clear();
+    BRepAdaptor_Curve C3D(edge);
+    double f = C3D.FirstParameter(), l = C3D.LastParameter(), len = thePnt1.Distance( thePnt2 );
+    if ( !StdMeshers_Regular_1D::computeInternalParameters( mesh, C3D, len, f, l, theParams, false))
+    {
+      for ( size_t i = 1; i < 15; ++i )
+        theParams.push_back( i/15. ); // ????
+    }
+    else
+    {
+      for (list<double>::iterator itU = theParams.begin(); itU != theParams.end(); ++itU )
+        *itU /= len;
+    }
+  }
+  virtual const list <const SMESHDS_Hypothesis *> &
+  GetUsedHypothesis(SMESH_Mesh &, const TopoDS_Shape &, const bool)
+  {
+    return SMESH_Algo::_usedHypList;
+  }
+  virtual bool CheckHypothesis(SMESH_Mesh&                          aMesh,
+                               const TopoDS_Shape&                  aShape,
+                               SMESH_Hypothesis::Hypothesis_Status& aStatus)
+  {
+    if ( !SMESH_Algo::_usedHypList.empty() )
+      return StdMeshers_Regular_1D::CheckHypothesis( aMesh, aShape, aStatus );
+    return true;
+  }
 };
  
 //================================================================================
@@ -82,20 +152,21 @@ public:
 //================================================================================
 
 StdMeshers_QuadFromMedialAxis_1D2D::StdMeshers_QuadFromMedialAxis_1D2D(int        hypId,
-                                                                       int        studyId,
                                                                        SMESH_Gen* gen)
-  : StdMeshers_Quadrangle_2D(hypId, studyId, gen),
+  : StdMeshers_Quadrangle_2D(hypId, gen),
     _regular1D( 0 )
 {
   _name = "QuadFromMedialAxis_1D2D";
   _shapeType = (1 << TopAbs_FACE);
   _onlyUnaryInput          = true;  // FACE by FACE so far
   _requireDiscreteBoundary = false; // make 1D by myself
-  _supportSubmeshes        = true; // make 1D by myself
+  _supportSubmeshes        = true;  // make 1D by myself
   _neededLowerHyps[ 1 ]    = true;  // suppress warning on hiding a global 1D algo
   _neededLowerHyps[ 2 ]    = true;  // suppress warning on hiding a global 2D algo
   _compatibleHypothesis.clear();
   _compatibleHypothesis.push_back("ViscousLayers2D");
+  _compatibleHypothesis.push_back("LayerDistribution2D");
+  _compatibleHypothesis.push_back("NumberOfLayers2D");
 }
 
 //================================================================================
@@ -121,6 +192,11 @@ bool StdMeshers_QuadFromMedialAxis_1D2D::CheckHypothesis(SMESH_Mesh&         aMe
                                                          Hypothesis_Status&  aStatus)
 {
   aStatus = HYP_OK;
+
+  // get one main optional hypothesis
+  const list <const SMESHDS_Hypothesis * >& hyps = GetUsedHypothesis(aMesh, aShape);
+  _hyp2D  = hyps.empty() ? 0 : hyps.front();
+
   return true; // does not require hypothesis
 }
 
@@ -134,13 +210,14 @@ namespace
    */
   struct SinuousFace
   {
-    FaceQuadStruct::Ptr   _quad;
-    vector< TopoDS_Edge > _edges;
-    vector< TopoDS_Edge > _sinuSide[2], _shortSide[2];
-    vector< TopoDS_Edge > _sinuEdges;
-    int                   _nbWires;
-    list< int >           _nbEdgesInWire;
-    TMergeMap             _nodesToMerge;
+    FaceQuadStruct::Ptr          _quad;
+    vector< TopoDS_Edge >        _edges;
+    vector< TopoDS_Edge >        _sinuSide[2], _shortSide[2];
+    vector< TopoDS_Edge >        _sinuEdges;
+    vector< Handle(Geom_Curve) > _sinuCurves;
+    int                          _nbWires;
+    list< int >                  _nbEdgesInWire;
+    TMergeMap                    _nodesToMerge;
 
     SinuousFace( const TopoDS_Face& f ): _quad( new FaceQuadStruct )
     {
@@ -152,6 +229,7 @@ namespace
       _quad->face = f;
     }
     const TopoDS_Face& Face() const { return _quad->face; }
+    bool IsRing() const { return _shortSide[0].empty() && !_sinuSide[0].empty(); }
   };
 
   //================================================================================
@@ -166,6 +244,43 @@ namespace
     }
   };
 
+  //================================================================================
+  /*!
+   * \brief Event listener which removes mesh from EDGEs when 2D hyps change
+   */
+  struct EdgeCleaner : public SMESH_subMeshEventListener
+  {
+    int _prevAlgoEvent;
+    EdgeCleaner():
+      SMESH_subMeshEventListener( /*isDeletable=*/true,
+                                  "StdMeshers_QuadFromMedialAxis_1D2D::EdgeCleaner")
+    {
+      _prevAlgoEvent = -1;
+    }
+    virtual void ProcessEvent(const int                       event,
+                              const int                       eventType,
+                              SMESH_subMesh*                  faceSubMesh,
+                              SMESH_subMeshEventListenerData* data,
+                              const SMESH_Hypothesis*         hyp)
+    {
+      if ( eventType == SMESH_subMesh::ALGO_EVENT )
+      {
+        _prevAlgoEvent = event;
+        return;
+      }
+      // SMESH_subMesh::COMPUTE_EVENT
+      if ( _prevAlgoEvent == SMESH_subMesh::REMOVE_HYP ||
+           _prevAlgoEvent == SMESH_subMesh::REMOVE_ALGO ||
+           _prevAlgoEvent == SMESH_subMesh::MODIF_HYP )
+      {
+        SMESH_subMeshIteratorPtr smIt = faceSubMesh->getDependsOnIterator(/*includeSelf=*/false);
+        while ( smIt->more() )
+          smIt->next()->ComputeStateEngine( SMESH_subMesh::CLEAN );
+      }
+      _prevAlgoEvent = -1;
+    }
+  };
+
   //================================================================================
   /*!
    * \brief Return a member of a std::pair
@@ -236,8 +351,8 @@ namespace
       algos[i] = sm->GetAlgo();
     }
 
-    const int nbSegDflt = mesh->GetGen()->GetDefaultNbSegments();
-    double minSegLen    = Precision::Infinite();
+    int nbSegDflt = mesh->GetGen() ? mesh->GetGen()->GetDefaultNbSegments() : 15;
+    double minSegLen = Precision::Infinite();
 
     for ( size_t i = 0; i < theEdges.size(); ++i )
     {
@@ -266,7 +381,8 @@ namespace
         tmpMesh.ShapeToMesh( TopoDS_Shape());
         tmpMesh.ShapeToMesh( theEdges[i] );
         try {
-          mesh->GetGen()->Compute( tmpMesh, theEdges[i], true, true ); // make nodes on VERTEXes
+          if ( !mesh->GetGen() ) continue; // tmp mesh
+          mesh->GetGen()->Compute( tmpMesh, theEdges[i], SMESH_Gen::SHAPE_ONLY_UPWARD ); // make nodes on VERTEXes
           if ( !algo->Compute( tmpMesh, theEdges[i] ))
             continue;
         }
@@ -401,6 +517,7 @@ namespace
       size_t nbOutEdges = theSinuFace._nbEdgesInWire.front();
       theSinuEdges[0].assign ( allEdges.begin(), allEdges.begin() + nbOutEdges );
       theSinuEdges[1].assign ( allEdges.begin() + nbOutEdges, allEdges.end() );
+      theSinuFace._sinuEdges = allEdges;
       return true;
     }
     if ( theSinuFace._nbWires > 2 )
@@ -436,8 +553,8 @@ namespace
                                allEdges, theShortEdges[ nbBranchPoints > 0 ] ))
         return false;
 
-      for ( size_t iS = 0; iS < theShortEdges[ nbBranchPoints ].size(); ++iS )
-        shortMap.Add( theShortEdges[ nbBranchPoints ][ iS ]);
+      for ( size_t iS = 0; iS < theShortEdges[ nbBranchPoints > 0 ].size(); ++iS )
+        shortMap.Add( theShortEdges[ nbBranchPoints > 0 ][ iS ]);
 
       ++nbBranchPoints;
     }
@@ -486,7 +603,7 @@ namespace
              theSinuEdges [0].size() > 0 && theSinuEdges [1].size() > 0 );
 
     // the sinuous EDGEs can be composite and C0 continuous,
-    // therefor we use a complex criterion to find TWO short non-sinuous EDGEs
+    // therefore we use a complex criterion to find TWO short non-sinuous EDGEs
     // and the rest EDGEs will be treated as sinuous.
     // A short edge should have the following features:
     // a) straight
@@ -623,7 +740,7 @@ namespace
     }
 
     // cout << "from salome.geom import geomBuilder" << endl;
-    // cout << "geompy = geomBuilder.New(salome.myStudy)" << endl;
+    // cout << "geompy = geomBuilder.New()" << endl;
     Handle(TColgp_HArray1OfPnt) points = new TColgp_HArray1OfPnt(1, pnt.size());
     for ( size_t i = 0; i < pnt.size(); ++i )
     {
@@ -679,20 +796,41 @@ namespace
                  const double                   theMinSegLen,
                  vector<double>&                theMAParams )
   {
-    // check if all EDGEs of one size are meshed, then MA discretization is not needed
+    // Check if all EDGEs of one size are meshed, then MA discretization is not needed
     SMESH_Mesh* mesh = theHelper.GetMesh();
     size_t nbComputedEdges[2] = { 0, 0 };
     for ( size_t iS = 0; iS < 2; ++iS )
       for ( size_t i = 0; i < theSinuFace._sinuSide[iS].size(); ++i )
       {
-        bool isComputed = ( ! mesh->GetSubMesh( theSinuFace._sinuSide[iS][i] )->IsEmpty() );
+        const TopoDS_Edge& sinuEdge = theSinuFace._sinuSide[iS][i];
+        SMESH_subMesh*           sm = mesh->GetSubMesh( sinuEdge );
+        bool             isComputed = ( !sm->IsEmpty() );
+        if ( isComputed )
+        {
+          TopAbs_ShapeEnum shape = getHypShape( mesh, sinuEdge );
+          if ( shape == TopAbs_SHAPE || shape <= TopAbs_FACE )
+          {
+            // EDGE computed using global hypothesis -> clear it
+            bool hasComputedFace = false;
+            PShapeIteratorPtr faceIt = theHelper.GetAncestors( sinuEdge, *mesh, TopAbs_FACE );
+            while ( const TopoDS_Shape* face = faceIt->next() )
+              if (( !face->IsSame( theSinuFace.Face() )) &&
+                  ( hasComputedFace = !mesh->GetSubMesh( *face )->IsEmpty() ))
+                break;
+            if ( !hasComputedFace )
+            {
+              sm->ComputeStateEngine( SMESH_subMesh::CLEAN );
+              isComputed = false;
+            }
+          }
+        }
         nbComputedEdges[ iS ] += isComputed;
       }
     if ( nbComputedEdges[0] == theSinuFace._sinuSide[0].size() ||
          nbComputedEdges[1] == theSinuFace._sinuSide[1].size() )
       return true; // discretization is not needed
 
-
+    // Make MA EDGE
     TopoDS_Edge branchEdge = makeEdgeFromMA( theHelper, theMA, theMinSegLen );
     if ( branchEdge.IsNull() )
       return false;
@@ -701,18 +839,24 @@ namespace
     // BRepTools::Write( branchEdge, file);
     // cout << "Write " << file << endl;
 
-    // look for a most local hyps assigned to theSinuEdges
-    TopoDS_Edge edge = theSinuFace._sinuEdges[0];
-    int mostSimpleShape = (int) getHypShape( mesh, edge );
-    for ( size_t i = 1; i < theSinuFace._sinuEdges.size(); ++i )
+
+    // Find 1D algo to mesh branchEdge
+  
+    // look for a most local 1D hyp assigned to the FACE
+    int mostSimpleShape = -1, maxShape = TopAbs_EDGE;
+    TopoDS_Edge edge;
+    for ( size_t i = 0; i < theSinuFace._sinuEdges.size(); ++i )
     {
-      int shapeType = (int) getHypShape( mesh, theSinuFace._sinuEdges[i] );
-      if ( shapeType > mostSimpleShape )
+      TopAbs_ShapeEnum shapeType = getHypShape( mesh, theSinuFace._sinuEdges[i] );
+      if ( mostSimpleShape < shapeType && shapeType < maxShape )
+      {
         edge = theSinuFace._sinuEdges[i];
+        mostSimpleShape = shapeType;
+      }
     }
 
     SMESH_Algo* algo = the1dAlgo;
-    if ( mostSimpleShape != TopAbs_SHAPE )
+    if ( mostSimpleShape > -1 )
     {
       algo = mesh->GetSubMesh( edge )->GetAlgo();
       SMESH_Hypothesis::Hypothesis_Status status;
@@ -723,7 +867,7 @@ namespace
     TmpMesh tmpMesh;
     tmpMesh.ShapeToMesh( branchEdge );
     try {
-      mesh->GetGen()->Compute( tmpMesh, branchEdge, true, true ); // make nodes on VERTEXes
+      mesh->GetGen()->Compute( tmpMesh, branchEdge, SMESH_Gen::SHAPE_ONLY_UPWARD ); // make nodes on VERTEXes
       if ( !algo->Compute( tmpMesh, branchEdge ))
         return false;
     }
@@ -807,7 +951,7 @@ namespace
   {
     const SMDS_MeshNode* _node;
     double               _u;
-    int                  _edgeInd; // index in theSinuEdges vector
+    size_t               _edgeInd; // index in theSinuEdges vector
 
     NodePoint(): _node(0), _u(0), _edgeInd(-1) {}
     NodePoint(const SMDS_MeshNode* n, double u, size_t iEdge ): _node(n), _u(u), _edgeInd(iEdge) {}
@@ -815,9 +959,10 @@ namespace
     NodePoint(const SMESH_MAT2d::BoundaryPoint& p) : _node(0), _u(p._param), _edgeInd(p._edgeIndex) {}
     gp_Pnt Point(const vector< Handle(Geom_Curve) >& curves) const
     {
-      return curves[ _edgeInd ]->Value( _u );
+      return _node ? SMESH_TNodeXYZ(_node) : curves[ _edgeInd ]->Value( _u );
     }
   };
+  typedef multimap< double, pair< NodePoint, NodePoint > > TMAPar2NPoints;
 
   //================================================================================
   /*!
@@ -830,11 +975,11 @@ namespace
    */
   //================================================================================
 
-  bool findVertex( NodePoint&                  theNodePnt,
-                   const vector<TopoDS_Edge>&  theSinuEdges,
-                   size_t                      theEdgeIndPrev,
-                   size_t                      theEdgeIndNext,
-                   SMESHDS_Mesh*               theMeshDS)
+  bool findVertexAndNode( NodePoint&                  theNodePnt,
+                          const vector<TopoDS_Edge>&  theSinuEdges,
+                          SMESHDS_Mesh*               theMeshDS = 0,
+                          size_t                      theEdgeIndPrev = 0,
+                          size_t                      theEdgeIndNext = 0)
   {
     if ( theNodePnt._edgeInd >= theSinuEdges.size() )
       return false;
@@ -851,7 +996,7 @@ namespace
     else if ( theEdgeIndPrev != theEdgeIndNext )
       TopExp::CommonVertex( theSinuEdges[theEdgeIndPrev], theSinuEdges[theEdgeIndNext], V );
 
-    if ( !V.IsNull() )
+    if ( !V.IsNull() && theMeshDS )
     {
       theNodePnt._node = SMESH_Algo::VertexNode( V, theMeshDS );
       if ( !theNodePnt._node )
@@ -860,9 +1005,8 @@ namespace
         theNodePnt._node = theMeshDS->AddNode( p.X(), p.Y(), p.Z() );
         theMeshDS->SetNodeOnVertex( theNodePnt._node, V );
       }
-      return true;
     }
-    return false;
+    return !V.IsNull();
   }
 
   //================================================================================
@@ -874,48 +1018,75 @@ namespace
    *  \param [in] theDivPoints - projections of VERTEXes to MA
    *  \param [in] theSinuEdges - the sinuous EDGEs
    *  \param [in] theSideEdgeIDs - indices of sinuous EDGEs per side
-   *  \param [in] theIsEdgeComputed - is sinuous EGDE is meshed
+   *  \param [in] theIsEdgeComputed - is sinuous EDGE is meshed
    *  \param [in,out] thePointsOnE - the map to fill
    *  \param [out] theNodes2Merge - the map of nodes to merge
    */
   //================================================================================
 
-  bool projectVertices( SMESH_MesherHelper&                           theHelper,
-                        //const double                                  theMinSegLen,
-                        const SMESH_MAT2d::MedialAxis&                theMA,
-                        const vector< SMESH_MAT2d::BranchPoint >&     theDivPoints,
-                        const vector< std::size_t > &                 theEdgeIDs1,
-                        const vector< std::size_t > &                 theEdgeIDs2,
-                        const vector<TopoDS_Edge>&                    theSinuEdges,
-                        const vector< Handle(Geom_Curve) >&           theCurves,
-                        const vector< bool >&                         theIsEdgeComputed,
-                        map< double, pair< NodePoint, NodePoint > > & thePointsOnE,
-                        TMergeMap&                                    theNodes2Merge)
+  bool projectVertices( SMESH_MesherHelper&                 theHelper,
+                        const SMESH_MAT2d::MedialAxis&      theMA,
+                        vector< SMESH_MAT2d::BranchPoint >& theDivPoints,
+                        const vector< std::size_t > &       theEdgeIDs1,
+                        const vector< std::size_t > &       theEdgeIDs2,
+                        const vector< bool >&               theIsEdgeComputed,
+                        TMAPar2NPoints &                    thePointsOnE,
+                        SinuousFace&                        theSinuFace)
   {
     if ( theDivPoints.empty() )
       return true;
 
     SMESHDS_Mesh* meshDS = theHelper.GetMeshDS();
+    const vector< TopoDS_Edge >&     theSinuEdges = theSinuFace._sinuEdges;
+    const vector< Handle(Geom_Curve) >& theCurves = theSinuFace._sinuCurves;
 
     double uMA;
-    SMESH_MAT2d::BoundaryPoint bp[2];
+    SMESH_MAT2d::BoundaryPoint bp[2]; // 2 sinuous sides
     const SMESH_MAT2d::Branch& branch = *theMA.getBranch(0);
+    {
+      // add to thePointsOnE NodePoint's of ends of theSinuEdges
+      if ( !branch.getBoundaryPoints( 0., bp[0], bp[1] ) ||
+           !theMA.getBoundary().moveToClosestEdgeEnd( bp[0] )) return false;
+      if ( !theSinuFace.IsRing() &&
+           !theMA.getBoundary().moveToClosestEdgeEnd( bp[1] )) return false;
+      NodePoint np0( bp[0] ), np1( bp[1] );
+      findVertexAndNode( np0, theSinuEdges, meshDS );
+      findVertexAndNode( np1, theSinuEdges, meshDS );
+      thePointsOnE.insert( make_pair( -0.1, make_pair( np0, np1 )));
+    }
+    if ( !theSinuFace.IsRing() )
+    {
+      if ( !branch.getBoundaryPoints( 1., bp[0], bp[1] ) ||
+           !theMA.getBoundary().moveToClosestEdgeEnd( bp[0] ) ||
+           !theMA.getBoundary().moveToClosestEdgeEnd( bp[1] )) return false;
+      NodePoint np0( bp[0] ), np1( bp[1] );
+      findVertexAndNode( np0, theSinuEdges, meshDS );
+      findVertexAndNode( np1, theSinuEdges, meshDS );
+      thePointsOnE.insert( make_pair( 1.1, make_pair( np0, np1)));
+    }
+    else
+    {
+      // project a VERTEX of outer sinuous side corresponding to branch(0.)
+      // which is not included into theDivPoints
+      if ( ! ( theDivPoints[0]._iEdge     == 0 &&
+               theDivPoints[0]._edgeParam == 0. )) // recursive call
+      {
+        SMESH_MAT2d::BranchPoint brp( &branch, 0, 0. );
+        vector< SMESH_MAT2d::BranchPoint > divPoint( 1, brp );
+        vector< std::size_t > edgeIDs1(2), edgeIDs2(2);
+        edgeIDs1[0] = theEdgeIDs1.back();
+        edgeIDs1[1] = theEdgeIDs1[0];
+        edgeIDs2[0] = theEdgeIDs2.back();
+        edgeIDs2[1] = theEdgeIDs2[0];
+        projectVertices( theHelper, theMA, divPoint, edgeIDs1, edgeIDs2,
+                         theIsEdgeComputed, thePointsOnE, theSinuFace );
+      }
+    }
+
+    // project theDivPoints and keep projections to merge
 
-    // fill a map holding NodePoint's of ends of theSinuEdges
-    map< double, pair< NodePoint, NodePoint > > extremaNP;
-    map< double, pair< NodePoint, NodePoint > >::iterator u2NP0, u2NP1;
-    if ( !branch.getBoundaryPoints( 0., bp[0], bp[1] ) ||
-         !theMA.getBoundary().moveToClosestEdgeEnd( bp[0] ) ||
-         !theMA.getBoundary().moveToClosestEdgeEnd( bp[1] )) return false;
-    u2NP0 = extremaNP.insert
-      ( make_pair( 0., make_pair( NodePoint( bp[0]), NodePoint( bp[1])))).first;
-    if ( !branch.getBoundaryPoints( 1., bp[0], bp[1] ) ||
-         !theMA.getBoundary().moveToClosestEdgeEnd( bp[0] ) ||
-         !theMA.getBoundary().moveToClosestEdgeEnd( bp[1] )) return false;
-    u2NP1 = extremaNP.insert
-      ( make_pair( 1., make_pair( NodePoint( bp[0]), NodePoint( bp[1])))).first;
-
-    // project theDivPoints
+    TMAPar2NPoints::iterator u2NP;
+    vector< TMAPar2NPoints::iterator > projToMerge;
     for ( size_t i = 0; i < theDivPoints.size(); ++i )
     {
       if ( !branch.getParameter( theDivPoints[i], uMA ))
@@ -928,22 +1099,48 @@ namespace
         NodePoint( bp[1] )
       };
       bool isVertex[2] = {
-        findVertex( np[0], theSinuEdges, theEdgeIDs1[i], theEdgeIDs1[i+1], meshDS ),
-        findVertex( np[1], theSinuEdges, theEdgeIDs2[i], theEdgeIDs2[i+1], meshDS )
+        findVertexAndNode( np[0], theSinuEdges, meshDS, theEdgeIDs1[i], theEdgeIDs1[i+1] ),
+        findVertexAndNode( np[1], theSinuEdges, meshDS, theEdgeIDs2[i], theEdgeIDs2[i+1] )
       };
+      const size_t iVert = isVertex[0] ? 0 : 1; // side with a VERTEX
+      const size_t iNode = 1 - iVert;           // opposite (meshed?) side
+
+      if ( isVertex[0] != isVertex[1] ) // try to find an opposite VERTEX
+      {
+        theMA.getBoundary().moveToClosestEdgeEnd( bp[iNode] ); // EDGE -> VERTEX
+        SMESH_MAT2d::BranchPoint brp;
+        theMA.getBoundary().getBranchPoint( bp[iNode], brp );  // WIRE -> MA
+        SMESH_MAT2d::BoundaryPoint bp2[2];
+        branch.getBoundaryPoints( brp, bp2[0], bp2[1] );       // MA -> WIRE
+        NodePoint np2[2] = { NodePoint( bp2[0]), NodePoint( bp2[1]) };
+        findVertexAndNode( np2[0], theSinuEdges, meshDS );
+        findVertexAndNode( np2[1], theSinuEdges, meshDS );
+        if ( np2[ iVert ]._node == np[ iVert ]._node &&
+             np2[ iNode ]._node)
+        {
+          np[ iNode ] = np2[ iNode ];
+          isVertex[ iNode ] = true;
+        }
+      }
 
-      map< double, pair< NodePoint, NodePoint > >::iterator u2NP =
-        thePointsOnE.insert( make_pair( uMA, make_pair( np[0], np[1]))).first;
+      u2NP = thePointsOnE.insert( make_pair( uMA, make_pair( np[0], np[1])));
 
       if ( !isVertex[0] && !isVertex[1] ) return false; // error
       if ( isVertex[0] && isVertex[1] )
         continue;
-      const size_t iVert = isVertex[0] ? 0 : 1;
-      const size_t iNode   = 1 - iVert;
 
-      bool isOppComputed = theIsEdgeComputed[ np[ iNode ]._edgeInd ];
-      if ( !isOppComputed )
-        continue;
+      // bool isOppComputed = theIsEdgeComputed[ np[ iNode ]._edgeInd ];
+      // if ( isOppComputed )
+        projToMerge.push_back( u2NP );
+    }
+
+    // merge projections
+
+    for ( size_t i = 0; i < projToMerge.size(); ++i )
+    {
+      u2NP = projToMerge[i];
+      const size_t iVert = get( u2NP->second, 0 )._node ? 0 : 1; // side with a VERTEX
+      const size_t iNode = 1 - iVert;                            // opposite (meshed?) side
 
       // a VERTEX is projected on a meshed EDGE; there are two options:
       // 1) a projected point is joined with a closet node if a strip between this and neighbor
@@ -953,14 +1150,12 @@ namespace
       // projection is set to the BoundaryPoint of this projection
 
       // evaluate distance to neighbor projections
-      const double rShort = 0.2;
-      bool isShortPrev[2], isShortNext[2];
-      map< double, pair< NodePoint, NodePoint > >::iterator u2NPPrev = u2NP, u2NPNext = u2NP;
+      const double rShort = 0.33;
+      bool isShortPrev[2], isShortNext[2], isPrevCloser[2];
+      TMAPar2NPoints::iterator u2NPPrev = u2NP, u2NPNext = u2NP;
       --u2NPPrev; ++u2NPNext;
-      bool hasPrev = ( u2NP     != thePointsOnE.begin() );
-      bool hasNext = ( u2NPNext != thePointsOnE.end() );
-      if ( !hasPrev ) u2NPPrev = u2NP0;
-      if ( !hasNext ) u2NPNext = u2NP1;
+      if ( u2NPNext == thePointsOnE.end() )
+        u2NPNext = thePointsOnE.begin(); // hope theSinuFace.IsRing()
       for ( int iS = 0; iS < 2; ++iS ) // side with Vertex and side with Nodes
       {
         NodePoint np     = get( u2NP->second,     iS );
@@ -972,60 +1167,490 @@ namespace
         double  distPrev = p.Distance( pPrev );
         double  distNext = p.Distance( pNext );
         double         r = distPrev / ( distPrev + distNext );
-        isShortPrev[iS] = ( r < rShort );
-        isShortNext[iS] = (( 1 - r ) > ( 1 - rShort ));
+        isShortPrev [iS] = ( r < rShort );
+        isShortNext [iS] = (( 1 - r ) < rShort );
+        isPrevCloser[iS] = (( r < 0.5 ) && ( theSinuFace.IsRing() || u2NPPrev->first > 0 ));
       }
-      // if ( !hasPrev ) isShortPrev[0] = isShortPrev[1] = false;
-      // if ( !hasNext ) isShortNext[0] = isShortNext[1] = false;
 
-      map< double, pair< NodePoint, NodePoint > >::iterator u2NPClose;
+      TMAPar2NPoints::iterator u2NPClose;
 
       if (( isShortPrev[0] && isShortPrev[1] ) || // option 2) -> remove a too close projection
           ( isShortNext[0] && isShortNext[1] ))
       {
-        u2NPClose = isShortPrev[0] ? u2NPPrev : u2NPNext;
+        u2NPClose = isPrevCloser[0] ? u2NPPrev : u2NPNext;
         NodePoint& npProj  = get( u2NP->second,      iNode ); // NP of VERTEX projection
+        NodePoint& npVert  = get( u2NP->second,      iVert ); // NP of VERTEX
         NodePoint npCloseN = get( u2NPClose->second, iNode ); // NP close to npProj
-        NodePoint npCloseV = get( u2NPClose->second, iVert ); // NP close to VERTEX
-        if ( !npCloseV._node )
+        NodePoint npCloseV = get( u2NPClose->second, iVert ); // NP close to npVert
+        if ( !npCloseV._node || npCloseV._node == npVert._node )
         {
           npProj = npCloseN;
-          thePointsOnE.erase( isShortPrev[0] ? u2NPPrev : u2NPNext );
+          thePointsOnE.erase( u2NPClose );
           continue;
         }
         else
         {
-          // can't remove the neighbor projection as it is also from VERTEX, -> option 1)
+          // can't remove the neighbor projection as it is also from VERTEX -> option 1)
         }
       }
       // else: option 1) - wide enough -> "duplicate" existing node
       {
-        u2NPClose = isShortPrev[ iNode ] ? u2NPPrev : u2NPNext;
+        u2NPClose = isPrevCloser[ iNode ] ? u2NPPrev : u2NPNext;
         NodePoint& npProj   = get( u2NP->second,      iNode ); // NP of VERTEX projection
         NodePoint& npCloseN = get( u2NPClose->second, iNode ); // NP close to npProj
-        // npProj._edgeInd = npCloseN._edgeInd;
+        npProj = npCloseN;
+        npProj._node = 0;
+        //npProj._edgeInd = npCloseN._edgeInd;
         // npProj._u       = npCloseN._u + 1e-3 * Abs( get( u2NPPrev->second, iNode )._u -
         //                                             get( u2NPNext->second, iNode )._u );
-        gp_Pnt        p = npProj.Point( theCurves );
-        npProj._node    = meshDS->AddNode( p.X(), p.Y(), p.Z() );
-        meshDS->SetNodeOnEdge( npProj._node, theSinuEdges[ npProj._edgeInd ], npProj._u  );
+        // gp_Pnt        p = npProj.Point( theCurves );
+        // npProj._node    = meshDS->AddNode( p.X(), p.Y(), p.Z() );
+        // meshDS->SetNodeOnEdge( npProj._node, theSinuEdges[ npProj._edgeInd ], npProj._u  );
 
-        theNodes2Merge[ npCloseN._node ].push_back( npProj._node );
+        //theNodes2Merge[ npCloseN._node ].push_back( npProj._node );
       }
     }
+
+    // remove auxiliary NodePoint's of ends of theSinuEdges
+    for ( u2NP = thePointsOnE.begin(); u2NP->first < 0; )
+      thePointsOnE.erase( u2NP++ );
+    thePointsOnE.erase( 1.1 );
+
     return true;
   }
 
+  double getUOnEdgeByPoint( const size_t     iEdge,
+                            const NodePoint* point,
+                            SinuousFace&     sinuFace )
+  {
+    if ( point->_edgeInd == iEdge )
+      return point->_u;
+
+    TopoDS_Vertex V0 = TopExp::FirstVertex( sinuFace._sinuEdges[ iEdge ]);
+    TopoDS_Vertex V1 = TopExp::LastVertex ( sinuFace._sinuEdges[ iEdge ]);
+    gp_Pnt p0 = BRep_Tool::Pnt( V0 );
+    gp_Pnt p1 = BRep_Tool::Pnt( V1 );
+    gp_Pnt  p = point->Point( sinuFace._sinuCurves );
+
+    double f,l;
+    BRep_Tool::Range( sinuFace._sinuEdges[ iEdge ], f,l );
+    return p.SquareDistance( p0 ) < p.SquareDistance( p1 ) ? f : l;
+  }
+
+  //================================================================================
+  /*!
+   * \brief Move coincident nodes to make node params on EDGE unique
+   *  \param [in] theHelper - the helper
+   *  \param [in] thePointsOnE - nodes on two opposite river sides
+   *  \param [in] theSinuFace - the sinuous FACE
+   *  \param [out] theNodes2Merge - the map of nodes to merge
+   */
+  //================================================================================
+
+  void separateNodes( SMESH_MesherHelper&            theHelper,
+                      const SMESH_MAT2d::MedialAxis& theMA,
+                      TMAPar2NPoints &               thePointsOnE,
+                      SinuousFace&                   theSinuFace,
+                      const vector< bool >&          theIsComputedEdge)
+  {
+    if ( thePointsOnE.size() < 2 )
+      return;
+
+    SMESHDS_Mesh* meshDS = theHelper.GetMeshDS();
+    const vector<TopoDS_Edge>&    theSinuEdges = theSinuFace._sinuEdges;
+    const vector< Handle(Geom_Curve) >& curves = theSinuFace._sinuCurves;
+
+    //SMESH_MAT2d::BoundaryPoint bp[2];
+    //const SMESH_MAT2d::Branch& branch = *theMA.getBranch(0);
+
+    typedef TMAPar2NPoints::iterator TIterator;
+
+    for ( int iSide = 0; iSide < 2; ++iSide ) // loop on two sinuous sides
+    {
+      // get a tolerance to compare points
+      double tol = Precision::Confusion();
+      for ( size_t i = 0; i < theSinuFace._sinuSide[ iSide ].size(); ++i )
+        tol = Max( tol , BRep_Tool::Tolerance( theSinuFace._sinuSide[ iSide ][ i ]));
+
+      // find coincident points
+      TIterator u2NP = thePointsOnE.begin();
+      vector< TIterator > sameU2NP( 1, u2NP++ );
+      while ( u2NP != thePointsOnE.end() )
+      {
+        for ( ; u2NP != thePointsOnE.end(); ++u2NP )
+        {
+          NodePoint& np1 = get( sameU2NP.back()->second, iSide );
+          NodePoint& np2 = get( u2NP           ->second, iSide );
+
+          if (( !np1._node || !np2._node ) &&
+              ( np1.Point( curves ).SquareDistance( np2.Point( curves )) < tol*tol ))
+          {
+            sameU2NP.push_back( u2NP );
+          }
+          else if ( sameU2NP.size() == 1 )
+          {
+            sameU2NP[ 0 ] = u2NP;
+          }
+          else
+          {
+            break;
+          }
+        }
+
+        if ( sameU2NP.size() > 1 )
+        {
+          // find an existing node on VERTEX among sameU2NP and get underlying EDGEs
+          const SMDS_MeshNode* existingNode = 0;
+          set< size_t > edgeInds;
+          NodePoint* np;
+          for ( size_t i = 0; i < sameU2NP.size(); ++i )
+          {
+            np = &get( sameU2NP[i]->second, iSide );
+            if ( np->_node )
+              if ( !existingNode || np->_node->GetPosition()->GetDim() == 0 )
+                existingNode = np->_node;
+            edgeInds.insert( np->_edgeInd );
+          }
+          list< const SMDS_MeshNode* >& mergeNodes = theSinuFace._nodesToMerge[ existingNode ];
+
+          TIterator u2NPprev = sameU2NP.front();
+          TIterator u2NPnext = sameU2NP.back() ;
+          if ( u2NPprev->first < 0. ) ++u2NPprev;
+          if ( u2NPnext->first > 1. ) --u2NPnext;
+
+          set< size_t >::iterator edgeID = edgeInds.begin();
+          for ( ; edgeID != edgeInds.end(); ++edgeID )
+          {
+            // get U range on iEdge within which the equal points will be distributed
+            double u0, u1;
+            np = &get( u2NPprev->second, iSide );
+            u0 = getUOnEdgeByPoint( *edgeID, np, theSinuFace );
+
+            np = &get( u2NPnext->second, iSide );
+            u1 = getUOnEdgeByPoint( *edgeID, np, theSinuFace );
+
+            if ( u0 == u1 )
+            {
+              if ( u2NPprev != thePointsOnE.begin() ) --u2NPprev;
+              if ( u2NPnext != --thePointsOnE.end() ) ++u2NPnext;
+              np = &get( u2NPprev->second, iSide );
+              u0 = getUOnEdgeByPoint( *edgeID, np, theSinuFace );
+              np = &get( u2NPnext->second, iSide );
+              u1 = getUOnEdgeByPoint( *edgeID, np, theSinuFace );
+            }
+
+            // distribute points and create nodes
+            double du = ( u1 - u0 ) / ( sameU2NP.size() + 1 /*!existingNode*/ );
+            double u  = u0 + du;
+            for ( size_t i = 0; i < sameU2NP.size(); ++i )
+            {
+              np = &get( sameU2NP[i]->second, iSide );
+              if ( !np->_node && *edgeID == np->_edgeInd )
+              {
+                np->_u = u;
+                u += du;
+                gp_Pnt p = np->Point( curves );
+                np->_node = meshDS->AddNode( p.X(), p.Y(), p.Z() );
+                meshDS->SetNodeOnEdge( np->_node, theSinuEdges[ *edgeID ], np->_u  );
+
+                if ( theIsComputedEdge[ *edgeID ])
+                  mergeNodes.push_back( np->_node );
+              }
+            }
+          }
+
+          sameU2NP.resize( 1 );
+          u2NP = ++sameU2NP.back();
+          sameU2NP[ 0 ] = u2NP;
+
+        } // if ( sameU2NP.size() > 1 )
+      } // while ( u2NP != thePointsOnE.end() )
+    } // for ( int iSide = 0; iSide < 2; ++iSide )
+
+    return;
+  } // separateNodes()
+
+
+  //================================================================================
+  /*!
+   * \brief Find association of nodes existing on the sinuous sides of a ring
+   *
+   * TMAPar2NPoints filled here is used in setQuadSides() only if theSinuFace.IsRing()
+   * to find most distant nodes of the inner and the outer wires
+   */
+  //================================================================================
+
+  void assocNodes( SMESH_MesherHelper&            theHelper,
+                   SinuousFace&                   theSinuFace,
+                   const SMESH_MAT2d::MedialAxis& theMA,
+                   TMAPar2NPoints &               thePointsOnE )
+  {
+    SMESH_Mesh*     mesh = theHelper.GetMesh();
+    SMESHDS_Mesh* meshDS = theHelper.GetMeshDS();
+
+    list< TopoDS_Edge > ee1( theSinuFace._sinuSide [0].begin(), theSinuFace._sinuSide [0].end() );
+    list< TopoDS_Edge > ee2( theSinuFace._sinuSide [1].begin(), theSinuFace._sinuSide [1].end() );
+    StdMeshers_FaceSide sideOut( theSinuFace.Face(), ee1, mesh, true, true, &theHelper );
+    StdMeshers_FaceSide sideIn ( theSinuFace.Face(), ee2, mesh, true, true, &theHelper );
+    const UVPtStructVec& uvsOut = sideOut.GetUVPtStruct();
+    const UVPtStructVec& uvsIn  = sideIn.GetUVPtStruct();
+    // if ( uvs1.size() != uvs2.size() )
+    //   return;
+
+    const SMESH_MAT2d::Branch& branch = *theMA.getBranch(0);
+    SMESH_MAT2d::BoundaryPoint bp[2];
+    SMESH_MAT2d::BranchPoint   brp;
+
+    map< double, const SMDS_MeshNode* > nodeParams; // params of existing nodes
+    map< double, const SMDS_MeshNode* >::iterator u2n;
+
+    // find a node of sideOut most distant from sideIn
+
+    vector< BRepAdaptor_Curve > curvesIn( theSinuFace._sinuSide[1].size() );
+    for ( size_t iE = 0; iE < theSinuFace._sinuSide[1].size(); ++iE )
+      curvesIn[ iE ].Initialize( theSinuFace._sinuSide[1][iE] );
+
+    double maxDist = 0;
+    SMESH_MAT2d::BoundaryPoint bpIn; // closest IN point
+    const SMDS_MeshNode*        nOut = 0;
+    const size_t              nbEOut = theSinuFace._sinuSide[0].size();
+    for ( size_t iE = 0; iE < nbEOut; ++iE )
+    {
+      const TopoDS_Edge& E = theSinuFace._sinuSide[0][iE];
+
+      if ( !SMESH_Algo::GetSortedNodesOnEdge( meshDS, E, /*skipMedium=*/true, nodeParams ))
+        return;
+      for ( u2n = nodeParams.begin(); u2n != nodeParams.end(); ++u2n )
+      {
+        // point on EDGE (u2n) --> MA point (brp)
+        if ( !theMA.getBoundary().getBranchPoint( iE, u2n->first, brp ) ||
+             !branch.getBoundaryPoints( brp, bp[0], bp[1] ))
+          return;
+        gp_Pnt pOut = SMESH_TNodeXYZ( u2n->second );
+        gp_Pnt pIn  = curvesIn[ bp[1]._edgeIndex - nbEOut ].Value( bp[1]._param );
+        double dist = pOut.SquareDistance( pIn );
+        if ( dist > maxDist )
+        {
+          maxDist = dist;
+          nOut    = u2n->second;
+          bpIn    = bp[1];
+        }
+      }
+    }
+    const SMDS_MeshNode* nIn = 0;
+    if ( !SMESH_Algo::GetSortedNodesOnEdge( meshDS,
+                                            theSinuFace._sinuEdges[ bpIn._edgeIndex ],
+                                            /*skipMedium=*/true,
+                                            nodeParams ))
+      return;
+    u2n = nodeParams.lower_bound( bpIn._param );
+    if ( u2n == nodeParams.end() )
+      nIn = nodeParams.rbegin()->second;
+    else
+      nIn = u2n->second;
+    
+    // find position of distant nodes in uvsOut and uvsIn
+    size_t iDistOut, iDistIn;
+    for ( iDistOut = 0; iDistOut < uvsOut.size(); ++iDistOut )
+    {
+      if ( uvsOut[iDistOut].node == nOut )
+        break;
+    }
+    for ( iDistIn = 0; iDistIn < uvsIn.size(); ++iDistIn )
+    {
+      if ( uvsIn[iDistIn].node == nIn )
+        break;
+    }
+    if ( iDistOut == uvsOut.size() || iDistIn == uvsIn.size() )
+      return;
+
+    // store opposite nodes in thePointsOnE (param and EDGE have no sense)
+    pair< NodePoint, NodePoint > oppNodes( NodePoint( nOut, 0, 0 ), NodePoint( nIn, 0, 0));
+    thePointsOnE.insert( make_pair( uvsOut[ iDistOut ].normParam, oppNodes ));
+    int iOut = iDistOut, iIn = iDistIn;
+    int i, nbNodes = std::min( uvsOut.size(), uvsIn.size() );
+    if ( nbNodes > 5 ) nbNodes = 5;
+    for ( i = 0, ++iOut, --iIn; i < nbNodes; ++iOut, --iIn, ++i )
+    {
+      iOut = theHelper.WrapIndex( iOut, uvsOut.size() );
+      iIn  = theHelper.WrapIndex( iIn,  uvsIn.size()  );
+      oppNodes.first._node  = uvsOut[ iOut ].node;
+      oppNodes.second._node = uvsIn[ iIn ].node;
+      thePointsOnE.insert( make_pair( uvsOut[ iOut ].normParam, oppNodes ));
+    }
+
+    return;
+  } // assocNodes()
+
+  //================================================================================
+  /*!
+   * \brief Setup sides of SinuousFace::_quad
+   *  \param [in] theHelper - helper
+   *  \param [in] thePointsOnEdges - NodePoint's on sinuous sides
+   *  \param [in,out] theSinuFace - the FACE
+   *  \param [in] the1dAlgo - algorithm to use for radial discretization of a ring FACE
+   *  \return bool - is OK
+   */
+  //================================================================================
+
+  bool setQuadSides(SMESH_MesherHelper&   theHelper,
+                    const TMAPar2NPoints& thePointsOnEdges,
+                    SinuousFace&          theFace,
+                    SMESH_Algo*           the1dAlgo)
+  {
+    SMESH_Mesh*               mesh = theHelper.GetMesh();
+    const TopoDS_Face&        face = theFace._quad->face;
+    SMESH_ProxyMesh::Ptr proxyMesh = StdMeshers_ViscousLayers2D::Compute( *mesh, face );
+    if ( !proxyMesh )
+      return false;
+
+    list< TopoDS_Edge > side[4];
+    side[0].insert( side[0].end(), theFace._shortSide[0].begin(), theFace._shortSide[0].end() );
+    side[1].insert( side[1].end(), theFace._sinuSide [1].begin(), theFace._sinuSide [1].end() );
+    side[2].insert( side[2].end(), theFace._shortSide[1].begin(), theFace._shortSide[1].end() );
+    side[3].insert( side[3].end(), theFace._sinuSide [0].begin(), theFace._sinuSide [0].end() );
+
+    for ( int i = 0; i < 4; ++i )
+    {
+      theFace._quad->side[i] = StdMeshers_FaceSide::New( face, side[i], mesh, i < QUAD_TOP_SIDE,
+                                                         /*skipMediumNodes=*/true,
+                                                         &theHelper, proxyMesh );
+    }
+
+    if ( theFace.IsRing() )
+    {
+      // --------------------------------------
+      // Discretize a ring in radial direction
+      // --------------------------------------
+
+      if ( thePointsOnEdges.size() < 4 )
+        return false;
+
+      int nbOut = theFace._quad->side[ 1 ].GetUVPtStruct().size();
+      int nbIn  = theFace._quad->side[ 3 ].GetUVPtStruct().size();
+      if ( nbOut == 0 || nbIn == 0 )
+        return false;
+
+      // find most distant opposite nodes
+      double maxDist = 0, dist;
+      TMAPar2NPoints::const_iterator u2NPdist, u2NP = thePointsOnEdges.begin();
+      for ( ; u2NP != thePointsOnEdges.end(); ++u2NP )
+      {
+        SMESH_TNodeXYZ        xyz( u2NP->second.first._node ); // node out
+        dist = xyz.SquareDistance( u2NP->second.second._node );// node in
+        if ( dist > maxDist )
+        {
+          u2NPdist = u2NP;
+          maxDist  = dist;
+        }
+      }
+      // compute distribution of radial nodes
+      list< double > params; // normalized params
+      static_cast< StdMeshers_QuadFromMedialAxis_1D2D::Algo1D* >
+        ( the1dAlgo )->ComputeDistribution( theHelper,
+                                            SMESH_TNodeXYZ( u2NPdist->second.first._node ),
+                                            SMESH_TNodeXYZ( u2NPdist->second.second._node ),
+                                            params );
+
+      // add a radial quad side
+
+      theHelper.SetElementsOnShape( true );
+      u2NP = thePointsOnEdges.begin();
+      const SMDS_MeshNode* nOut = u2NP->second.first._node;
+      const SMDS_MeshNode*  nIn = u2NP->second.second._node;
+      nOut = proxyMesh->GetProxyNode( nOut );
+      nIn  = proxyMesh->GetProxyNode( nIn );
+      gp_XY uvOut = theHelper.GetNodeUV( face, nOut );
+      gp_XY uvIn  = theHelper.GetNodeUV( face, nIn );
+      Handle(Geom_Surface) surface = BRep_Tool::Surface( face );
+      UVPtStructVec uvsNew; UVPtStruct uvPt;
+      uvPt.node = nOut;
+      uvPt.u    = uvOut.X();
+      uvPt.v    = uvOut.Y();
+      uvsNew.push_back( uvPt );
+      for (list<double>::iterator itU = params.begin(); itU != params.end(); ++itU )
+      {
+        gp_XY uv  = ( 1 - *itU ) * uvOut + *itU * uvIn; // applied in direction Out -> In
+        gp_Pnt p  = surface->Value( uv.X(), uv.Y() );
+        uvPt.node = theHelper.AddNode( p.X(), p.Y(), p.Z(), /*id=*/0, uv.X(), uv.Y() );
+        uvPt.u    = uv.X();
+        uvPt.v    = uv.Y();
+        uvsNew.push_back( uvPt );
+      }
+      uvPt.node = nIn;
+      uvPt.u    = uvIn.X();
+      uvPt.v    = uvIn.Y();
+      uvsNew.push_back( uvPt );
+
+      theFace._quad->side[ 0 ] = StdMeshers_FaceSide::New( uvsNew );
+      theFace._quad->side[ 2 ] = theFace._quad->side[ 0 ];
+      if ( nbIn != nbOut )
+        theFace._quad->side[ 2 ] = StdMeshers_FaceSide::New( uvsNew );
+
+      // assure that the outer sinuous side starts at nOut
+      {
+        const UVPtStructVec& uvsOut = theFace._quad->side[ 3 ].GetUVPtStruct(); // _sinuSide[0]
+        size_t i; // find UVPtStruct holding nOut
+        for ( i = 0; i < uvsOut.size(); ++i )
+          if ( nOut == uvsOut[i].node )
+            break;
+        if ( i == uvsOut.size() )
+          return false;
+
+        if ( i != 0  &&  i != uvsOut.size()-1 )
+        {
+          // create a new OUT quad side
+          uvsNew.clear();
+          uvsNew.reserve( uvsOut.size() );
+          uvsNew.insert( uvsNew.end(), uvsOut.begin() + i, uvsOut.end() );
+          uvsNew.insert( uvsNew.end(), uvsOut.begin() + 1, uvsOut.begin() + i + 1);
+          theFace._quad->side[ 3 ] = StdMeshers_FaceSide::New( uvsNew );
+        }
+      }
+
+      // rotate the IN side if opposite nodes of IN and OUT sides don't match
+
+      const SMDS_MeshNode * nIn0 = theFace._quad->side[ 1 ].First().node;
+      if ( nIn0 != nIn )
+      {
+        nIn  = proxyMesh->GetProxyNode( nIn );
+        const UVPtStructVec& uvsIn = theFace._quad->side[ 1 ].GetUVPtStruct(); // _sinuSide[1]
+        size_t i; // find UVPtStruct holding nIn
+        for ( i = 0; i < uvsIn.size(); ++i )
+          if ( nIn == uvsIn[i].node )
+            break;
+        if ( i == uvsIn.size() )
+          return false;
+
+        // create a new IN quad side
+        uvsNew.clear();
+        uvsNew.reserve( uvsIn.size() );
+        uvsNew.insert( uvsNew.end(), uvsIn.begin() + i, uvsIn.end() );
+        uvsNew.insert( uvsNew.end(), uvsIn.begin() + 1, uvsIn.begin() + i + 1);
+        theFace._quad->side[ 1 ] = StdMeshers_FaceSide::New( uvsNew );
+      }
+
+      if ( theFace._quad->side[ 1 ].GetUVPtStruct().empty() ||
+           theFace._quad->side[ 3 ].GetUVPtStruct().empty() )
+        return false;
+
+    } // if ( theFace.IsRing() )
+
+    return true;
+
+  } // setQuadSides()
+
   //================================================================================
   /*!
    * \brief Divide the sinuous EDGEs by projecting the division point of Medial
-   *        Axis to the EGDEs
+   *        Axis to the EDGEs
    *  \param [in] theHelper - the helper
    *  \param [in] theMinSegLen - minimal segment length
    *  \param [in] theMA - the Medial Axis
    *  \param [in] theMAParams - parameters of division points of \a theMA
    *  \param [in] theSinuEdges - the EDGEs to make nodes on
    *  \param [in] theSinuSide0Size - the number of EDGEs in the 1st sinuous side
+   *  \param [in] the1dAlgo - algorithm to use for radial discretization of a ring FACE
    *  \return bool - is OK or not
    */
   //================================================================================
@@ -1034,7 +1659,8 @@ namespace
                          double                     /*theMinSegLen*/,
                          SMESH_MAT2d::MedialAxis&   theMA,
                          vector<double>&            theMAParams,
-                         SinuousFace&               theSinuFace)
+                         SinuousFace&               theSinuFace,
+                         SMESH_Algo*                the1dAlgo)
   {
     if ( theMA.nbBranches() != 1 )
       return false;
@@ -1048,11 +1674,13 @@ namespace
     SMESHDS_Mesh* meshDS = theHelper.GetMeshDS();
     double f,l;
 
+    // get data of sinuous EDGEs and remove unnecessary nodes
     const vector< TopoDS_Edge >& theSinuEdges = theSinuFace._sinuEdges;
-    vector< Handle(Geom_Curve) > curves ( theSinuEdges.size() );
-    vector< int >                edgeIDs( theSinuEdges.size() );
-    vector< bool >            isComputed( theSinuEdges.size() );
-    //bool hasComputed = false;
+    vector< Handle(Geom_Curve) >& curves      = theSinuFace._sinuCurves;
+    vector< int >                edgeIDs   ( theSinuEdges.size() ); // IDs in the main shape
+    vector< bool >               isComputed( theSinuEdges.size() );
+    curves.resize( theSinuEdges.size(), 0 );
+    bool                         allComputed = true;
     for ( size_t i = 0; i < theSinuEdges.size(); ++i )
     {
       curves[i] = BRep_Tool::Curve( theSinuEdges[i], f,l );
@@ -1061,164 +1689,235 @@ namespace
       SMESH_subMesh* sm = mesh->GetSubMesh( theSinuEdges[i] );
       edgeIDs   [i] = sm->GetId();
       isComputed[i] = ( !sm->IsEmpty() );
-      if ( isComputed[i] )
-      {
-        TopAbs_ShapeEnum shape = getHypShape( mesh, theSinuEdges[i] );
-        if ( shape == TopAbs_SHAPE || shape <= TopAbs_FACE )
-        {
-          // EDGE computed using global hypothesis -> clear it
-          bool hasComputedFace = false;
-          PShapeIteratorPtr faceIt = theHelper.GetAncestors( theSinuEdges[i], *mesh, TopAbs_FACE );
-          while ( const TopoDS_Shape* face = faceIt->next() )
-            if (( !face->IsSame( theSinuFace.Face())) &&
-                ( hasComputedFace = !mesh->GetSubMesh( *face )->IsEmpty() ))
-              break;
-          if ( !hasComputedFace )
-            sm->ComputeStateEngine( SMESH_subMesh::CLEAN );
-          isComputed[i] = false;
-        }
-      }
+      if ( !isComputed[i] )
+        allComputed = false;
     }
 
     const SMESH_MAT2d::Branch& branch = *theMA.getBranch(0);
     SMESH_MAT2d::BoundaryPoint bp[2];
 
-    vector< std::size_t > edgeIDs1, edgeIDs2;
-    vector< SMESH_MAT2d::BranchPoint > divPoints;
-    branch.getOppositeGeomEdges( edgeIDs1, edgeIDs2, divPoints );
-    for ( size_t i = 0; i < edgeIDs1.size(); ++i )
-      if ( isComputed[ edgeIDs1[i]] &&
-           isComputed[ edgeIDs2[i]])
-        return false;
-
-    // map param on MA to parameters of nodes on a pair of theSinuEdges
-    typedef map< double, pair< NodePoint, NodePoint > > TMAPar2NPoints;
     TMAPar2NPoints pointsOnE;
-    vector<double> maParams;
-
-    // compute params of nodes on EDGEs by projecting division points from MA
-    //const double tol = 1e-5 * theMAParams.back();
-    size_t iEdgePair = 0;
-    while ( iEdgePair < edgeIDs1.size() )
+    // check that computed EDGEs are opposite and equally meshed
+    if ( allComputed )
     {
-      if ( isComputed[ edgeIDs1[ iEdgePair ]] ||
-           isComputed[ edgeIDs2[ iEdgePair ]])
-      {
-        // "projection" from one side to the other
-
-        size_t iEdgeComputed = edgeIDs1[iEdgePair], iSideComputed = 0;
-        if ( !isComputed[ iEdgeComputed ])
-          ++iSideComputed, iEdgeComputed = edgeIDs2[iEdgePair];
+      // int nbNodes[2] = { 0, 0 };
+      // for ( int iSide = 0; iSide < 2; ++iSide ) // loop on two sinuous sides
+      //   nbNodes[ iSide ] += meshDS->MeshElements( theSinuFace._sinuSide[ iSide ])->NbNodes() - 1;
 
-        map< double, const SMDS_MeshNode* > nodeParams; // params of existing nodes
-        if ( !SMESH_Algo::GetSortedNodesOnEdge( meshDS, theSinuEdges[ iEdgeComputed ], /*skipMedium=*/true, nodeParams ))
-          return false;
+      // if ( nbNodes[0] != nbNodes[1] )
+      //   return false;
 
-        SMESH_MAT2d::BoundaryPoint& bndPnt = bp[ 1-iSideComputed ];
-        SMESH_MAT2d::BranchPoint brp;
-        NodePoint npN, npB;
-        NodePoint& np0 = iSideComputed ? npB : npN;
-        NodePoint& np1 = iSideComputed ? npN : npB;
+      if ( theSinuFace.IsRing() )
+        assocNodes( theHelper, theSinuFace, theMA, pointsOnE );
+    }
+    else
+    {
+      vector< std::size_t > edgeIDs1, edgeIDs2; // indices in theSinuEdges
+      vector< SMESH_MAT2d::BranchPoint > divPoints;
+      branch.getOppositeGeomEdges( edgeIDs1, edgeIDs2, divPoints );
 
-        double maParam1st, maParamLast, maParam;
-        if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, nodeParams.begin()->first, brp ))
+      for ( size_t i = 0; i < edgeIDs1.size(); ++i )
+        if ( isComputed[ edgeIDs1[i]] &&
+             isComputed[ edgeIDs2[i]] )
+        {
+          int nbNodes1 = meshDS->MeshElements(edgeIDs[ edgeIDs1[i]] )->NbNodes();
+          int nbNodes2 = meshDS->MeshElements(edgeIDs[ edgeIDs2[i]] )->NbNodes();
+          if ( nbNodes1 != nbNodes2 )
             return false;
-        branch.getParameter( brp, maParam1st );
-        if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, nodeParams.rbegin()->first, brp ))
+          if (( int(i)-1 >= 0 ) &&
+              ( edgeIDs1[i-1] == edgeIDs1[i] ||
+                edgeIDs2[i-1] == edgeIDs2[i] ))
             return false;
-        branch.getParameter( brp, maParamLast );
+          if (( i+1 < edgeIDs1.size() ) &&
+              ( edgeIDs1[i+1] == edgeIDs1[i] ||
+                edgeIDs2[i+1] == edgeIDs2[i] ))
+            return false;
+        }
 
-        map< double, const SMDS_MeshNode* >::iterator u2n = nodeParams.begin(), u2nEnd = --nodeParams.end();
-        TMAPar2NPoints::iterator end = pointsOnE.end(), pos = end;
-        TMAPar2NPoints::iterator & hint = (maParamLast > maParam1st) ? end : pos;
-        for ( ++u2n; u2n != u2nEnd; ++u2n )
+      // map (param on MA) to (parameters of nodes on a pair of theSinuEdges)
+      vector<double> maParams;
+      set<int>       projectedEdges; // treated EDGEs which 'isComputed'
+
+      // compute params of nodes on EDGEs by projecting division points from MA
+
+      for ( size_t iEdgePair = 0; iEdgePair < edgeIDs1.size(); ++iEdgePair )
+        // loop on pairs of opposite EDGEs
+      {
+        if ( projectedEdges.count( edgeIDs1[ iEdgePair ]) ||
+             projectedEdges.count( edgeIDs2[ iEdgePair ]) )
+          continue;
+
+        // --------------------------------------------------------------------------------
+        if ( isComputed[ edgeIDs1[ iEdgePair ]] !=                    // one EDGE is meshed
+             isComputed[ edgeIDs2[ iEdgePair ]])
         {
-          if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, u2n->first, brp ))
+          // "projection" from one side to the other
+
+          size_t iEdgeComputed = edgeIDs1[iEdgePair], iSideComputed = 0;
+          if ( !isComputed[ iEdgeComputed ])
+            ++iSideComputed, iEdgeComputed = edgeIDs2[iEdgePair];
+
+          map< double, const SMDS_MeshNode* > nodeParams; // params of existing nodes
+          if ( !SMESH_Algo::GetSortedNodesOnEdge( meshDS, theSinuEdges[ iEdgeComputed ], /*skipMedium=*/true, nodeParams ))
             return false;
-          if ( !branch.getBoundaryPoints( brp, bp[0], bp[1] ))
+
+          projectedEdges.insert( iEdgeComputed );
+
+          SMESH_MAT2d::BoundaryPoint& bndPnt = bp[ 1-iSideComputed ];
+          SMESH_MAT2d::BranchPoint brp;
+          NodePoint npN, npB; // NodePoint's initialized by node and BoundaryPoint
+          NodePoint& np0 = iSideComputed ? npB : npN;
+          NodePoint& np1 = iSideComputed ? npN : npB;
+
+          double maParam1st, maParamLast, maParam;
+          if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, nodeParams.begin()->first, brp ))
             return false;
-          if ( !branch.getParameter( brp, maParam ))
+          branch.getParameter( brp, maParam1st );
+          if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, nodeParams.rbegin()->first, brp ))
             return false;
+          branch.getParameter( brp, maParamLast );
 
-          npN = NodePoint( u2n->second, u2n->first, iEdgeComputed );
-          npB = NodePoint( bndPnt );
-          pos = pointsOnE.insert( hint, make_pair( maParam, make_pair( np0, np1 )));
+          map< double, const SMDS_MeshNode* >::iterator u2n = nodeParams.begin(), u2nEnd = nodeParams.end();
+          TMAPar2NPoints::iterator end = pointsOnE.end(), pos = end;
+          TMAPar2NPoints::iterator & hint = (maParamLast > maParam1st) ? end : pos;
+          for ( ++u2n, --u2nEnd; u2n != u2nEnd; ++u2n )
+          {
+            // point on EDGE (u2n) --> MA point (brp)
+            if ( !theMA.getBoundary().getBranchPoint( iEdgeComputed, u2n->first, brp ))
+              return false;
+            // MA point --> points on 2 EDGEs (bp)
+            if ( !branch.getBoundaryPoints( brp, bp[0], bp[1] ) ||
+                 !branch.getParameter( brp, maParam ))
+              return false;
+
+            npN = NodePoint( u2n->second, u2n->first, iEdgeComputed );
+            npB = NodePoint( bndPnt );
+            pos = pointsOnE.insert( hint, make_pair( maParam, make_pair( np0, np1 )));
+          }
         }
+        // --------------------------------------------------------------------------------
+        else if ( !isComputed[ edgeIDs1[ iEdgePair ]] &&         // none of EDGEs is meshed
+                  !isComputed[ edgeIDs2[ iEdgePair ]])
+        {
+          // "projection" from MA
+          maParams.clear();
+          if ( !getParamsForEdgePair( iEdgePair, divPoints, theMAParams, maParams ))
+            return false;
 
-        // move iEdgePair forward
-        while ( iEdgePair < edgeIDs1.size() )
-          if ( edgeIDs1[ iEdgePair ] == bp[0]._edgeIndex &&
-               edgeIDs2[ iEdgePair ] == bp[1]._edgeIndex )
-            break;
-          else
-            ++iEdgePair;
-      }
-      else
-      {
-        // projection from MA
-        maParams.clear();
-        if ( !getParamsForEdgePair( iEdgePair, divPoints, theMAParams, maParams ))
-          return false;
+          for ( size_t i = 1; i < maParams.size()-1; ++i )
+          {
+            if ( !branch.getBoundaryPoints( maParams[i], bp[0], bp[1] ))
+              return false;
 
-        for ( size_t i = 1; i < maParams.size()-1; ++i )
+            pointsOnE.insert( pointsOnE.end(), make_pair( maParams[i], make_pair( NodePoint(bp[0]),
+                                                                                  NodePoint(bp[1]))));
+          }
+        }
+        // --------------------------------------------------------------------------------
+        else if ( isComputed[ edgeIDs1[ iEdgePair ]] &&             // equally meshed EDGES
+                  isComputed[ edgeIDs2[ iEdgePair ]])
         {
-          if ( !branch.getBoundaryPoints( maParams[i], bp[0], bp[1] ))
+          // add existing nodes
+
+          size_t iE0 = edgeIDs1[ iEdgePair ];
+          size_t iE1 = edgeIDs2[ iEdgePair ];
+          map< double, const SMDS_MeshNode* > nodeParams[2]; // params of existing nodes
+          if ( !SMESH_Algo::GetSortedNodesOnEdge( meshDS, theSinuEdges[ iE0 ],
+                                                  /*skipMedium=*/false, nodeParams[0] ) ||
+               !SMESH_Algo::GetSortedNodesOnEdge( meshDS, theSinuEdges[ iE1 ],
+                                                  /*skipMedium=*/false, nodeParams[1] ) ||
+               nodeParams[0].size() != nodeParams[1].size() )
             return false;
 
-          pointsOnE.insert( pointsOnE.end(), make_pair( maParams[i], make_pair( NodePoint(bp[0]),
-                                                                                NodePoint(bp[1]))));
+          if ( nodeParams[0].size() <= 2 )
+            continue; // nodes on VERTEXes only
+
+          bool reverse = ( theSinuEdges[0].Orientation() == theSinuEdges[1].Orientation() );
+          double maParam;
+          SMESH_MAT2d::BranchPoint brp;
+          std::pair< NodePoint, NodePoint > npPair;
+
+          map< double, const SMDS_MeshNode* >::iterator
+            u2n0F = ++nodeParams[0].begin(),
+            u2n1F = ++nodeParams[1].begin();
+          map< double, const SMDS_MeshNode* >::reverse_iterator
+            u2n1R = ++nodeParams[1].rbegin();
+          for ( ; u2n0F != nodeParams[0].end(); ++u2n0F )
+          {
+            if ( !theMA.getBoundary().getBranchPoint( iE0, u2n0F->first, brp ) ||
+                 !branch.getParameter( brp, maParam ))
+              return false;
+
+            npPair.first = NodePoint( u2n0F->second, u2n0F->first, iE0 );
+            if ( reverse )
+            {
+              npPair.second = NodePoint( u2n1R->second, u2n1R->first, iE1 );
+              ++u2n1R;
+            }
+            else
+            {
+              npPair.second = NodePoint( u2n1F->second, u2n1F->first, iE1 );
+              ++u2n1F;
+            }
+            pointsOnE.insert( make_pair( maParam, npPair ));
+          }
         }
-      }
-      ++iEdgePair;
-    }
+      }  // loop on pairs of opposite EDGEs
 
-    if ( !projectVertices( theHelper, theMA, divPoints, edgeIDs1, edgeIDs2, theSinuEdges,
-                           curves, isComputed, pointsOnE, theSinuFace._nodesToMerge ))
-      return false;
+      if ( !projectVertices( theHelper, theMA, divPoints, edgeIDs1, edgeIDs2,
+                             isComputed, pointsOnE, theSinuFace ))
+        return false;
 
-    // create nodes
-    TMAPar2NPoints::iterator u2np = pointsOnE.begin();
-    for ( ; u2np != pointsOnE.end(); ++u2np )
-    {
-      NodePoint* np[2] = { & u2np->second.first, & u2np->second.second };
-      for ( int iSide = 0; iSide < 2; ++iSide )
+      separateNodes( theHelper, theMA, pointsOnE, theSinuFace, isComputed );
+
+      // create nodes
+      TMAPar2NPoints::iterator u2np = pointsOnE.begin();
+      for ( ; u2np != pointsOnE.end(); ++u2np )
       {
-        if ( np[ iSide ]->_node ) continue;
-        size_t       iEdge = np[ iSide ]->_edgeInd;
-        double           u = np[ iSide ]->_u;
-        gp_Pnt           p = curves[ iEdge ]->Value( u );
-        np[ iSide ]->_node = meshDS->AddNode( p.X(), p.Y(), p.Z() );
-        meshDS->SetNodeOnEdge( np[ iSide ]->_node, edgeIDs[ iEdge ], u );
+        NodePoint* np[2] = { & u2np->second.first, & u2np->second.second };
+        for ( int iSide = 0; iSide < 2; ++iSide )
+        {
+          if ( np[ iSide ]->_node ) continue;
+          size_t       iEdge = np[ iSide ]->_edgeInd;
+          double           u = np[ iSide ]->_u;
+          gp_Pnt           p = curves[ iEdge ]->Value( u );
+          np[ iSide ]->_node = meshDS->AddNode( p.X(), p.Y(), p.Z() );
+          meshDS->SetNodeOnEdge( np[ iSide ]->_node, edgeIDs[ iEdge ], u );
+        }
       }
-    }
 
-    // create mesh segments on EDGEs
-    theHelper.SetElementsOnShape( false );
-    TopoDS_Face face = TopoDS::Face( theHelper.GetSubShape() );
-    for ( size_t i = 0; i < theSinuEdges.size(); ++i )
-    {
-      SMESH_subMesh* sm = mesh->GetSubMesh( theSinuEdges[i] );
-      if ( sm->GetSubMeshDS() && sm->GetSubMeshDS()->NbElements() > 0 )
-        continue;
+      // create mesh segments on EDGEs
+      theHelper.SetElementsOnShape( false );
+      TopoDS_Face face = TopoDS::Face( theHelper.GetSubShape() );
+      for ( size_t i = 0; i < theSinuEdges.size(); ++i )
+      {
+        SMESH_subMesh* sm = mesh->GetSubMesh( theSinuEdges[i] );
+        if ( sm->GetSubMeshDS() && sm->GetSubMeshDS()->NbElements() > 0 )
+          continue;
+
+        StdMeshers_FaceSide side( face, theSinuEdges[i], mesh,
+                                  /*isFwd=*/true, /*skipMediumNodes=*/true, &theHelper );
+        vector<const SMDS_MeshNode*> nodes = side.GetOrderedNodes();
+        for ( size_t in = 1; in < nodes.size(); ++in )
+        {
+          const SMDS_MeshElement* seg = theHelper.AddEdge( nodes[in-1], nodes[in], 0, false );
+          meshDS->SetMeshElementOnShape( seg, edgeIDs[ i ] );
+        }
+      }
 
-      StdMeshers_FaceSide side( face, theSinuEdges[i], mesh,
-                                /*isFwd=*/true, /*skipMediumNodes=*/true );
-      vector<const SMDS_MeshNode*> nodes = side.GetOrderedNodes();
-      for ( size_t in = 1; in < nodes.size(); ++in )
+      // update sub-meshes on VERTEXes
+      for ( size_t i = 0; i < theSinuEdges.size(); ++i )
       {
-        const SMDS_MeshElement* seg = theHelper.AddEdge( nodes[in-1], nodes[in], 0, false );
-        meshDS->SetMeshElementOnShape( seg, edgeIDs[ i ] );
+        mesh->GetSubMesh( theHelper.IthVertex( 0, theSinuEdges[i] ))
+          ->ComputeStateEngine( SMESH_subMesh::CHECK_COMPUTE_STATE );
+        mesh->GetSubMesh( theHelper.IthVertex( 1, theSinuEdges[i] ))
+          ->ComputeStateEngine( SMESH_subMesh::CHECK_COMPUTE_STATE );
       }
     }
 
-    // update sub-meshes on VERTEXes
-    for ( size_t i = 0; i < theSinuEdges.size(); ++i )
-    {
-      mesh->GetSubMesh( theHelper.IthVertex( 0, theSinuEdges[i] ))
-        ->ComputeStateEngine( SMESH_subMesh::CHECK_COMPUTE_STATE );
-      mesh->GetSubMesh( theHelper.IthVertex( 1, theSinuEdges[i] ))
-        ->ComputeStateEngine( SMESH_subMesh::CHECK_COMPUTE_STATE );
-    }
+    // Setup sides of a quadrangle
+    if ( !setQuadSides( theHelper, pointsOnE, theSinuFace, the1dAlgo ))
+      return false;
 
     return true;
   }
@@ -1231,16 +1930,30 @@ namespace
 
   bool computeShortEdges( SMESH_MesherHelper&        theHelper,
                           const vector<TopoDS_Edge>& theShortEdges,
-                          SMESH_Algo*                the1dAlgo )
+                          SMESH_Algo*                the1dAlgo,
+                          const bool                 theHasRadialHyp,
+                          const bool                 theIs2nd)
   {
+    SMESH_Hypothesis::Hypothesis_Status aStatus;
     for ( size_t i = 0; i < theShortEdges.size(); ++i )
     {
-      theHelper.GetGen()->Compute( *theHelper.GetMesh(), theShortEdges[i], true, true );
+      if ( !theHasRadialHyp )
+        // use global hyps
+        theHelper.GetGen()->Compute( *theHelper.GetMesh(), theShortEdges[i],
+                                     SMESH_Gen::SHAPE_ONLY_UPWARD );
 
       SMESH_subMesh* sm = theHelper.GetMesh()->GetSubMesh(theShortEdges[i] );
       if ( sm->IsEmpty() )
       {
+        // use 2D hyp or minSegLen
         try {
+          // compute VERTEXes
+          SMESH_subMeshIteratorPtr smIt = sm->getDependsOnIterator(/*includeSelf=*/false);
+          while ( smIt->more() )
+            smIt->next()->ComputeStateEngine( SMESH_subMesh::COMPUTE );
+
+          // compute EDGE
+          the1dAlgo->CheckHypothesis( *theHelper.GetMesh(), theShortEdges[i], aStatus );
           if ( !the1dAlgo->Compute( *theHelper.GetMesh(), theShortEdges[i] ))
             return false;
         }
@@ -1274,12 +1987,12 @@ namespace
     const double dksi = 0.5, deta = 0.5;
     const double  dksi2 = dksi*dksi, deta2 = deta*deta;
     double err = 0., g11, g22, g12;
-    int nbErr = 0;
+    //int nbErr = 0;
 
     FaceQuadStruct& q = *quad;
     UVPtStruct pNew;
 
-    double refArea = area( q.UVPt(0,0), q.UVPt(1,0), q.UVPt(1,1) );
+    //double refArea = area( q.UVPt(0,0), q.UVPt(1,0), q.UVPt(1,1) );
 
     for ( int iLoop = 0; iLoop < nbLoops; ++iLoop )
     {
@@ -1353,6 +2066,7 @@ namespace
     TMergeMap::iterator n2nn = theSinuFace._nodesToMerge.begin();
     for ( ; n2nn != theSinuFace._nodesToMerge.end(); ++n2nn )
     {
+      if ( !n2nn->first ) continue;
       nodesGroups.push_back( list< const SMDS_MeshNode* >() );
       list< const SMDS_MeshNode* > & group = nodesGroups.back();
 
@@ -1364,6 +2078,17 @@ namespace
 
 } // namespace
 
+//================================================================================
+/*!
+ * \brief Sets event listener which removes mesh from EDGEs when 2D hyps change
+ */
+//================================================================================
+
+void StdMeshers_QuadFromMedialAxis_1D2D::SetEventListener(SMESH_subMesh* faceSubMesh)
+{
+  faceSubMesh->SetEventListener( new EdgeCleaner, 0, faceSubMesh );
+}
+
 //================================================================================
 /*!
  * \brief Create quadrangle elements
@@ -1375,57 +2100,41 @@ namespace
  */
 //================================================================================
 
-bool StdMeshers_QuadFromMedialAxis_1D2D::computeQuads( SMESH_MesherHelper&       theHelper,
-                                                       const TopoDS_Face&        theFace,
-                                                       const vector<TopoDS_Edge> theSinuEdges[2],
-                                                       const vector<TopoDS_Edge> theShortEdges[2])
+bool StdMeshers_QuadFromMedialAxis_1D2D::computeQuads( SMESH_MesherHelper& theHelper,
+                                                       FaceQuadStruct::Ptr theQuad)
 {
-  SMESH_Mesh* mesh = theHelper.GetMesh();
-  SMESH_ProxyMesh::Ptr proxyMesh = StdMeshers_ViscousLayers2D::Compute( *mesh, theFace );
-  if ( !proxyMesh )
-    return false;
-
-  StdMeshers_Quadrangle_2D::myProxyMesh  = proxyMesh;
   StdMeshers_Quadrangle_2D::myHelper     = &theHelper;
   StdMeshers_Quadrangle_2D::myNeedSmooth = false;
   StdMeshers_Quadrangle_2D::myCheckOri   = false;
   StdMeshers_Quadrangle_2D::myQuadList.clear();
 
-  // fill FaceQuadStruct
-
-  list< TopoDS_Edge > side[4];
-  side[0].insert( side[0].end(), theShortEdges[0].begin(), theShortEdges[0].end() );
-  side[1].insert( side[1].end(), theSinuEdges[1].begin(),  theSinuEdges[1].end() );
-  side[2].insert( side[2].end(), theShortEdges[1].begin(), theShortEdges[1].end() );
-  side[3].insert( side[3].end(), theSinuEdges[0].begin(),  theSinuEdges[0].end() );
-
-  FaceQuadStruct::Ptr quad( new FaceQuadStruct );
-  quad->side.resize( 4 );
-  quad->face = theFace;
-  for ( int i = 0; i < 4; ++i )
-  {
-    quad->side[i] = StdMeshers_FaceSide::New( theFace, side[i], mesh, i < QUAD_TOP_SIDE,
-                                              /*skipMediumNodes=*/true, proxyMesh );
-  }
-  int nbNodesShort0 = quad->side[0].NbPoints();
-  int nbNodesShort1 = quad->side[2].NbPoints();
+  int nbNodesShort0 = theQuad->side[0].NbPoints();
+  int nbNodesShort1 = theQuad->side[2].NbPoints();
+  int nbNodesSinu0  = theQuad->side[1].NbPoints();
+  int nbNodesSinu1  = theQuad->side[3].NbPoints();
 
   // compute UV of internal points
-  myQuadList.push_back( quad );
-  if ( !StdMeshers_Quadrangle_2D::setNormalizedGrid( quad ))
-    return false;
+  myQuadList.push_back( theQuad );
+  // if ( !StdMeshers_Quadrangle_2D::setNormalizedGrid( theQuad ))
+  //   return false;
 
   // elliptic smooth of internal points to get boundary cell normal to the boundary
-  ellipticSmooth( quad, 1 );
-
+  bool isRing = theQuad->side[0].grid->Edge(0).IsNull();
+  if ( !isRing ) {
+    if ( !StdMeshers_Quadrangle_2D::setNormalizedGrid( theQuad ))
+      return false;
+    ellipticSmooth( theQuad, 1 );
+  }
   // create quadrangles
   bool ok;
-  if ( nbNodesShort0 == nbNodesShort1 )
-    ok = StdMeshers_Quadrangle_2D::computeQuadDominant( *mesh, theFace, quad );
+  theHelper.SetElementsOnShape( true );
+  if ( nbNodesShort0 == nbNodesShort1 && nbNodesSinu0 == nbNodesSinu1 )
+    ok = StdMeshers_Quadrangle_2D::computeQuadDominant( *theHelper.GetMesh(),
+                                                        theQuad->face, theQuad );
   else
-    ok = StdMeshers_Quadrangle_2D::computeTriangles( *mesh, theFace, quad );
+    ok = StdMeshers_Quadrangle_2D::computeTriangles( *theHelper.GetMesh(),
+                                                     theQuad->face, theQuad );
 
-  StdMeshers_Quadrangle_2D::myProxyMesh.reset();
   StdMeshers_Quadrangle_2D::myHelper = 0;
 
   return ok;
@@ -1452,36 +2161,35 @@ bool StdMeshers_QuadFromMedialAxis_1D2D::Compute(SMESH_Mesh&         theMesh,
 
   if ( getSinuousEdges( helper, sinuFace ))
   {
-    _progress = 0.2;
-
-    // if ( sinuFace._sinuEdges.size() > 2 )
-    //   return error(COMPERR_BAD_SHAPE, "Not yet supported case" );
+    _progress = 0.4;
 
     double minSegLen = getMinSegLen( helper, sinuFace._sinuEdges );
     SMESH_MAT2d::MedialAxis ma( F, sinuFace._sinuEdges, minSegLen, /*ignoreCorners=*/true );
 
     if ( !_regular1D )
-      _regular1D = new Algo1D( _studyId, _gen );
+      _regular1D = new Algo1D( _gen );
     _regular1D->SetSegmentLength( minSegLen );
 
     vector<double> maParams;
     if ( ! divideMA( helper, ma, sinuFace, _regular1D, minSegLen, maParams ))
       return error(COMPERR_BAD_SHAPE);
 
-    _progress = 0.4;
+    _progress = 0.8;
+    if ( _hyp2D )
+      _regular1D->SetRadialDistribution( _hyp2D );
 
-    if ( !computeShortEdges( helper, sinuFace._shortSide[0], _regular1D ) ||
-         !computeShortEdges( helper, sinuFace._shortSide[1], _regular1D ))
+    if ( !computeShortEdges( helper, sinuFace._shortSide[0], _regular1D, _hyp2D, 0 ) ||
+         !computeShortEdges( helper, sinuFace._shortSide[1], _regular1D, _hyp2D, 1 ))
       return error("Failed to mesh short edges");
 
-    _progress = 0.6;
+    _progress = 0.85;
 
-    if ( !computeSinuEdges( helper, minSegLen, ma, maParams, sinuFace ))
+    if ( !computeSinuEdges( helper, minSegLen, ma, maParams, sinuFace, _regular1D ))
       return error("Failed to mesh sinuous edges");
 
-    _progress = 0.8;
+    _progress = 0.9;
 
-    bool ok = computeQuads( helper, F, sinuFace._sinuSide, sinuFace._shortSide );
+    bool ok = computeQuads( helper, sinuFace._quad );
 
     if ( ok )
       mergeNodes( helper, sinuFace );
@@ -1507,3 +2215,31 @@ bool StdMeshers_QuadFromMedialAxis_1D2D::Evaluate(SMESH_Mesh &         theMesh,
   return StdMeshers_Quadrangle_2D::Evaluate(theMesh,theShape,theResMap);
 }
 
+//================================================================================
+/*!
+ * \brief Return true if the algorithm can mesh this shape
+ *  \param [in] aShape - shape to check
+ *  \param [in] toCheckAll - if true, this check returns OK if all shapes are OK,
+ *              else, returns OK if at least one shape is OK
+ */
+//================================================================================
+
+bool StdMeshers_QuadFromMedialAxis_1D2D::IsApplicable( const TopoDS_Shape & aShape,
+                                                       bool                 toCheckAll )
+{
+  TmpMesh tmpMesh;
+  SMESH_MesherHelper helper( tmpMesh );
+
+  int nbFoundFaces = 0;
+  for (TopExp_Explorer exp( aShape, TopAbs_FACE ); exp.More(); exp.Next(), ++nbFoundFaces )
+  {
+    const TopoDS_Face& face = TopoDS::Face( exp.Current() );
+    SinuousFace sinuFace( face );
+    bool isApplicable = getSinuousEdges( helper, sinuFace );
+
+    if ( toCheckAll  && !isApplicable ) return false;
+    if ( !toCheckAll &&  isApplicable ) return true;
+  }
+  return ( toCheckAll && nbFoundFaces != 0 );
+}
+