22772: EDF 8916 SMESH: Issue with a quadrangle mesh

Consider edges on period boundary as seam ones

diff --git a/src/SMESH/SMESH_MesherHelper.cxx b/src/SMESH/SMESH_MesherHelper.cxx
index e89a75f56125776d276a982470c10bd040461d6d..4449efbce31db19f2ce544689a35d68281427b22 100644 (file)
--- a/src/SMESH/SMESH_MesherHelper.cxx
+++ b/src/SMESH/SMESH_MesherHelper.cxx
@@ -242,40 +242,44 @@ void SMESH_MesherHelper::SetSubShape(const TopoDS_Shape& aSh)
   for ( TopExp_Explorer eF( aSh, TopAbs_FACE ); eF.More(); eF.Next() )
   {
     const TopoDS_Face& face = TopoDS::Face( eF.Current() );
+    BRepAdaptor_Surface surf( face, false );
+    if ( surf.IsUPeriodic() || surf.IsUClosed() ) {
+      myParIndex |= U_periodic;
+      myPar1[0] = surf.FirstUParameter();
+      myPar2[0] = surf.LastUParameter();
+    }
+    if ( surf.IsVPeriodic() || surf.IsVClosed() ) {
+      myParIndex |= V_periodic;
+      myPar1[1] = surf.FirstVParameter();
+      myPar2[1] = surf.LastVParameter();
+    }
 
-    // if ( surface->IsUPeriodic() || surface->IsVPeriodic() ||
-    //      surface->IsUClosed()   || surface->IsVClosed() )
+    for (TopExp_Explorer exp( face, TopAbs_EDGE ); exp.More(); exp.Next())
     {
-      //while ( surface->IsKind(STANDARD_TYPE(Geom_RectangularTrimmedSurface )))
-      //surface = Handle(Geom_RectangularTrimmedSurface)::DownCast( surface )->BasisSurface();
-
-      for (TopExp_Explorer exp( face, TopAbs_EDGE ); exp.More(); exp.Next())
+      // look for a "seam" edge, actually an edge on period boundary
+      const TopoDS_Edge& edge = TopoDS::Edge( exp.Current() );
+      if ( myParIndex )
       {
-        // look for a seam edge
-        TopoDS_Edge edge = TopoDS::Edge( exp.Current() );
-        if ( BRep_Tool::IsClosed( edge, face )) {
-          // initialize myPar1, myPar2 and myParIndex
+        bool isSeam = BRep_Tool::IsClosed( edge, face );
+        if ( !isSeam )
+        {
           gp_Pnt2d uv1, uv2;
           BRep_Tool::UVPoints( edge, face, uv1, uv2 );
-          if ( Abs( uv1.Coord(1) - uv2.Coord(1) ) < Abs( uv1.Coord(2) - uv2.Coord(2) ))
+          const double du = Abs( uv1.Coord(1) - uv2.Coord(1) );
+          const double dv = Abs( uv1.Coord(2) - uv2.Coord(2) );
+          if      ( du < Precision::PConfusion() )
           {
-            double u1 = uv1.Coord(1);
-            edge.Reverse();
-            BRep_Tool::UVPoints( edge, face, uv1, uv2 );
-            double u2 = uv1.Coord(1);
-            myParIndex |= U_periodic;
-            myPar1[0] = Min( u1, u2 );
-            myPar2[0] = Max( u1, u2 );
+            isSeam = ( Abs( uv1.Coord(1) - myPar1[0] ) < Precision::PConfusion() ||
+                       Abs( uv1.Coord(1) - myPar2[0] ) < Precision::PConfusion() );
           }
-          else {
-            double v1 = uv1.Coord(2);
-            edge.Reverse();
-            BRep_Tool::UVPoints( edge, face, uv1, uv2 );
-            double v2 = uv1.Coord(2);
-            myParIndex |= V_periodic;
-            myPar1[1] = Min( v1, v2 );
-            myPar2[1] = Max( v1, v2 );
+          else if ( dv < Precision::PConfusion() )
+          {
+            isSeam = ( Abs( uv1.Coord(2) - myPar1[1] ) < Precision::PConfusion() ||
+                       Abs( uv1.Coord(2) - myPar2[1] ) < Precision::PConfusion() );
           }
+        }
+        if ( isSeam )
+        {
           // store seam shape indices, negative if shape encounters twice
           int edgeID = meshDS->ShapeToIndex( edge );
           mySeamShapeIds.insert( IsSeamShape( edgeID ) ? -edgeID : edgeID );
@@ -284,27 +288,12 @@ void SMESH_MesherHelper::SetSubShape(const TopoDS_Shape& aSh)
             mySeamShapeIds.insert( IsSeamShape( vertexID ) ? -vertexID : vertexID );
           }
         }
-
-        // look for a degenerated edge
-        if ( SMESH_Algo::isDegenerated( edge )) {
-          myDegenShapeIds.insert( meshDS->ShapeToIndex( edge ));
-          for ( TopExp_Explorer v( edge, TopAbs_VERTEX ); v.More(); v.Next() )
-            myDegenShapeIds.insert( meshDS->ShapeToIndex( v.Current() ));
-        }
       }
-      if ( !myDegenShapeIds.empty() && !myParIndex )
-      {
-        BRepAdaptor_Surface surf( face, false );
-        if ( surf.IsUPeriodic() || surf.IsUClosed() ) {
-          myParIndex |= U_periodic;
-          myPar1[0] = surf.FirstUParameter();
-          myPar2[0] = surf.LastUParameter();
-        }
-        else if ( surf.IsVPeriodic() || surf.IsVClosed() ) {
-          myParIndex |= V_periodic;
-          myPar1[1] = surf.FirstVParameter();
-          myPar2[1] = surf.LastVParameter();
-        }
+      // look for a degenerated edge
+      if ( SMESH_Algo::isDegenerated( edge )) {
+        myDegenShapeIds.insert( meshDS->ShapeToIndex( edge ));
+        for ( TopExp_Explorer v( edge, TopAbs_VERTEX ); v.More(); v.Next() )
+          myDegenShapeIds.insert( meshDS->ShapeToIndex( v.Current() ));
       }
     }
   }
@@ -2541,6 +2530,75 @@ bool SMESH_MesherHelper::IsStructured( SMESH_subMesh* faceSM )
   return true;
 }
 
+//=======================================================================
+//function : IsDistorted2D
+//purpose  : Return true if 2D mesh on FACE is ditorted
+//=======================================================================
+
+bool SMESH_MesherHelper::IsDistorted2D( SMESH_subMesh* faceSM )
+{
+  if ( !faceSM || faceSM->GetSubShape().ShapeType() != TopAbs_FACE )
+    return false;
+
+  bool haveBadFaces = false;
+
+  SMESH_MesherHelper helper( *faceSM->GetFather() );
+  helper.SetSubShape( faceSM->GetSubShape() );
+
+  const TopoDS_Face&  F = TopoDS::Face( faceSM->GetSubShape() );
+  SMESHDS_SubMesh* smDS = helper.GetMeshDS()->MeshElements( F );
+  if ( !smDS || smDS->NbElements() == 0 ) return false;
+
+  SMDS_ElemIteratorPtr faceIt = smDS->GetElements();
+  double prevArea2D = 0;
+  vector< const SMDS_MeshNode* > nodes;
+  vector< gp_XY >                uv;
+  while ( faceIt->more() && !haveBadFaces )
+  {
+    const SMDS_MeshElement* face = faceIt->next();
+
+    // get nodes
+    nodes.resize( face->NbCornerNodes() );
+    SMDS_MeshElement::iterator n = face->begin_nodes();
+    for ( size_t i = 0; i < nodes.size(); ++n, ++i )
+      nodes[ i ] = *n;
+
+    // avoid elems on degenarate shapes as UV on them can be wrong
+    if ( helper.HasDegeneratedEdges() )
+    {
+      bool isOnDegen = false;
+      for ( size_t i = 0; ( i < nodes.size() && !isOnDegen ); ++i )
+        isOnDegen = helper.IsDegenShape( nodes[ i ]->getshapeId() );
+      if ( isOnDegen )
+        continue;
+    }
+    // prepare to getting UVs
+    const SMDS_MeshNode* inFaceNode = 0;
+    if ( helper.HasSeam() )
+      for ( size_t i = 0; ( i < nodes.size() && !inFaceNode ); ++i )
+        if ( !helper.IsSeamShape( nodes[ i ]->getshapeId() ))
+          inFaceNode = nodes[ i ];
+
+    // get UVs
+    uv.resize( nodes.size() );
+    for ( size_t i = 0; i < nodes.size(); ++i )
+      uv[ i ] = helper.GetNodeUV( F, nodes[ i ], inFaceNode );
+
+    // compare orientation of triangles
+    for ( int iT = 0, nbT = nodes.size()-2; iT < nbT; ++iT )
+    {
+      gp_XY v1 = uv[ iT+1 ] - uv[ 0 ];
+      gp_XY v2 = uv[ iT+2 ] - uv[ 0 ];
+      double area2D = v2 ^ v1;
+      if (( haveBadFaces = ( area2D * prevArea2D < 0 )))
+        break;
+      prevArea2D = area2D;
+    }
+  }
+
+  return haveBadFaces;
+}
+
 //================================================================================
 /*!
  * \brief Find out elements orientation on a geometrical face

diff --git a/src/SMESH/SMESH_MesherHelper.hxx b/src/SMESH/SMESH_MesherHelper.hxx
index 3e67d13649e8f020a9c2fb2227d9b03ea416c6a0..430e6f374c71ee4a384073b07500d1283e6f0bbc 100644 (file)
--- a/src/SMESH/SMESH_MesherHelper.hxx
+++ b/src/SMESH/SMESH_MesherHelper.hxx
@@ -117,6 +117,11 @@ class SMESH_EXPORT SMESH_MesherHelper
    */
   static bool IsStructured( SMESH_subMesh* faceSM );
 
+  /*!
+   * \brief Return true if 2D mesh on FACE is distored
+   */
+  static bool IsDistorted2D( SMESH_subMesh* faceSM );
+
   /*!
    * \brief Returns true if given node is medium
     * \param n - node to check

diff --git a/src/StdMeshers/StdMeshers_Projection_2D.cxx b/src/StdMeshers/StdMeshers_Projection_2D.cxx
index 78c16a4ebd35632b268b396ad0999bb8a545c9a6..9db5ee4c32c16d28f41e21af8d4879b85a132579 100644 (file)
--- a/src/StdMeshers/StdMeshers_Projection_2D.cxx
+++ b/src/StdMeshers/StdMeshers_Projection_2D.cxx
@@ -920,79 +920,24 @@ namespace {
   //================================================================================
 
   void fixDistortedFaces( SMESH_MesherHelper& helper,
-                          TSideVector&        )
+                          TSideVector&        tgtWires )
   {
-    // Detect bad faces
+    SMESH_subMesh* faceSM = helper.GetMesh()->GetSubMesh( helper.GetSubShape() );
 
-    bool haveBadFaces = false;
-
-    const TopoDS_Face&  F = TopoDS::Face( helper.GetSubShape() );
-    SMESHDS_SubMesh* smDS = helper.GetMeshDS()->MeshElements( F );
-    if ( !smDS || smDS->NbElements() == 0 ) return;
-
-    SMDS_ElemIteratorPtr faceIt = smDS->GetElements();
-    double prevArea2D = 0;
-    vector< const SMDS_MeshNode* > nodes;
-    vector< gp_XY >                uv;
-    while ( faceIt->more() && !haveBadFaces )
-    {
-      const SMDS_MeshElement* face = faceIt->next();
-
-      // get nodes
-      nodes.resize( face->NbCornerNodes() );
-      SMDS_MeshElement::iterator n = face->begin_nodes();
-      for ( size_t i = 0; i < nodes.size(); ++n, ++i )
-        nodes[ i ] = *n;
-
-      // avoid elems on degenarate shapes as UV on them can be wrong
-      if ( helper.HasDegeneratedEdges() )
-      {
-        bool isOnDegen = false;
-        for ( size_t i = 0; ( i < nodes.size() && !isOnDegen ); ++i )
-          isOnDegen = helper.IsDegenShape( nodes[ i ]->getshapeId() );
-        if ( isOnDegen )
-          continue;
-      }
-      // prepare to getting UVs
-      const SMDS_MeshNode* inFaceNode = 0;
-      if ( helper.HasSeam() )
-        for ( size_t i = 0; ( i < nodes.size() && !inFaceNode ); ++i )
-          if ( !helper.IsSeamShape( nodes[ i ]->getshapeId() ))
-            inFaceNode = nodes[ i ];
-
-      // get UVs
-      uv.resize( nodes.size() );
-      for ( size_t i = 0; i < nodes.size(); ++i )
-        uv[ i ] = helper.GetNodeUV( F, nodes[ i ], inFaceNode );
-
-      // compare orientation of triangles
-      for ( int iT = 0, nbT = nodes.size()-2; iT < nbT; ++iT )
-      {
-        gp_XY v1 = uv[ iT+1 ] - uv[ 0 ];
-        gp_XY v2 = uv[ iT+2 ] - uv[ 0 ];
-        double area2D = v2 ^ v1;
-        if (( haveBadFaces = ( area2D * prevArea2D < 0 )))
-          break;
-        prevArea2D = area2D;
-      }
-    }
-
-    // Fix faces
-
-    if ( haveBadFaces )
+    if ( helper.IsDistorted2D( faceSM ))
     {
       SMESH_MeshEditor editor( helper.GetMesh() );
+      SMESHDS_SubMesh* smDS = faceSM->GetSubMeshDS();
+      const TopoDS_Face&  F = TopoDS::Face( faceSM->GetSubShape() );
 
       TIDSortedElemSet faces;
+      SMDS_ElemIteratorPtr faceIt = smDS->GetElements();
       for ( faceIt = smDS->GetElements(); faceIt->more(); )
         faces.insert( faces.end(), faceIt->next() );
 
       // choose smoothing algo
       //SMESH_MeshEditor:: SmoothMethod algo = SMESH_MeshEditor::CENTROIDAL;
       bool isConcaveBoundary = false;
-      TError err;
-      TSideVector tgtWires =
-        StdMeshers_FaceSide::GetFaceWires( F, *helper.GetMesh(),/*skipMediumNodes=*/0, err);
       for ( size_t iW = 0; iW < tgtWires.size() && !isConcaveBoundary; ++iW )
       {
         TopoDS_Edge prevEdge = tgtWires[iW]->Edge( tgtWires[iW]->NbEdges() - 1 );