020461: EDF 1102 GHS3DPLUGIN: Bad detection of volumes with Ghs3d mesh

SMESH_MesherHelper:

-  void SetCheckNodePosition(bool toCheck) { myCheckNodePos = toCheck; }
   /*!
+   * \brief Check and fix node UV on a face
+   *  \retval bool - false if UV is bad and could not be fixed
+   */
+  bool CheckNodeUV(const TopoDS_Face&   F,
+                   const SMDS_MeshNode* n,
+                   gp_XY&               uv,
+                   const double         tol) const;

-  bool            myCheckNodePos;
+  std::set< int > myOkNodePosShapes;

src/SMESH/SMESH_MeshEditor.cxx

@@ -7689,7 +7689,6 @@ void SMESH_MeshEditor::ConvertToQuadratic(const bool theForce3d)
         SMESH_subMesh* sm = smIt->next();
         if ( SMESHDS_SubMesh *smDS = sm->GetSubMeshDS() ) {
           aHelper.SetSubShape( sm->GetSubShape() );
-          if ( !theForce3d) aHelper.SetCheckNodePosition(true);
           nbCheckedElems += convertElemToQuadratic(smDS, aHelper, theForce3d);
         }
       }

src/SMESH/SMESH_MesherHelper.cxx

@@ -71,7 +71,7 @@ namespace {
 //================================================================================
 
 SMESH_MesherHelper::SMESH_MesherHelper(SMESH_Mesh& theMesh)
-  : myMesh(&theMesh), myShapeID(0), myCreateQuadratic(false), myCheckNodePos(false)
+  : myMesh(&theMesh), myShapeID(0), myCreateQuadratic(false)
 {
   mySetElemOnShape = ( ! myMesh->HasShapeToMesh() );
 }
@@ -326,9 +326,8 @@ gp_Pnt2d SMESH_MesherHelper::GetUVOnSeam( const gp_Pnt2d& uv1, const gp_Pnt2d& u
  * \param F - the face
  * \param n - the node
  * \param n2 - a node of element being created located inside a face
+ * \param check - optional flag returing false if found UV are invalid
  * \retval gp_XY - resulting UV
- * 
- * Auxilary function called form GetMediumNode()
  */
 //=======================================================================
 
@@ -339,37 +338,14 @@ gp_XY SMESH_MesherHelper::GetNodeUV(const TopoDS_Face&   F,
 {
   gp_Pnt2d uv( 1e100, 1e100 );
   const SMDS_PositionPtr Pos = n->GetPosition();
+  bool uvOK = false;
   if(Pos->GetTypeOfPosition()==SMDS_TOP_FACE)
   {
     // node has position on face
     const SMDS_FacePosition* fpos =
       static_cast<const SMDS_FacePosition*>(n->GetPosition().get());
     uv.SetCoord(fpos->GetUParameter(),fpos->GetVParameter());
-    if ( check && *check )
+    uvOK = CheckNodeUV( F, n, uv.ChangeCoord(), BRep_Tool::Tolerance( F ));
-    {
-      // check that uv is correct
-      TopLoc_Location loc;
-      Handle(Geom_Surface) surface = BRep_Tool::Surface( F,loc );
-      double tol = 2 * BRep_Tool::Tolerance( F );
-      gp_Pnt nodePnt = XYZ( n );
-      if ( !loc.IsIdentity() ) nodePnt.Transform( loc.Transformation().Inverted() );
-      if ( nodePnt.Distance( surface->Value( uv.X(), uv.Y() )) > tol ) {
-        // uv incorrect, project the node to surface
-        GeomAPI_ProjectPointOnSurf projector( nodePnt, surface, tol );
-        if ( !projector.IsDone() || projector.NbPoints() < 1 ) {
-          MESSAGE( "SMESH_MesherHelper::GetNodeUV() failed to project" )
-          return uv.XY();
-        }
-        Quantity_Parameter U,V;
-        projector.LowerDistanceParameters(U,V);
-        if ( nodePnt.Distance( surface->Value( U, V )) > tol )
-          MESSAGE( "SMESH_MesherHelper::GetNodeUV(), invalid projection" );
-        uv.SetCoord( U,V );
-      }
-      else if ( uv.XY().Modulus() > numeric_limits<double>::min() ) {
-        *check = false; // parameters are OK, do not check further more
-      }
-    }
   }
   else if(Pos->GetTypeOfPosition()==SMDS_TOP_EDGE)
   {
@@ -383,11 +359,15 @@ gp_XY SMESH_MesherHelper::GetNodeUV(const TopoDS_Face&   F,
     double f, l;
     Handle(Geom2d_Curve) C2d = BRep_Tool::CurveOnSurface(E, F, f, l);
     uv = C2d->Value( epos->GetUParameter() );
+    uvOK = CheckNodeUV( F, n, uv.ChangeCoord(), BRep_Tool::Tolerance( E ));
+
     // for a node on a seam edge select one of UVs on 2 pcurves
     if ( n2 && IsSeamShape( edgeID ) )
+    {
       uv = GetUVOnSeam( uv, GetNodeUV( F, n2, 0 ));
-
+    }
-    // adjust uv to period
+    else
+    { // adjust uv to period
       TopLoc_Location loc;
       Handle(Geom_Surface) S = BRep_Tool::Surface(F,loc);
       Standard_Boolean isUPeriodic = S->IsUPeriodic();
@@ -401,21 +381,21 @@ gp_XY SMESH_MesherHelper::GetNodeUV(const TopoDS_Face&   F,
           uv.SetY( uv.Y() + ShapeAnalysis::AdjustToPeriod(uv.Y(),VF,VL));
       }
     }
+  }
   else if(Pos->GetTypeOfPosition()==SMDS_TOP_VERTEX)
   {
     if ( int vertexID = n->GetPosition()->GetShapeId() ) {
-      bool ok = true;
       const TopoDS_Vertex& V = TopoDS::Vertex(GetMeshDS()->IndexToShape(vertexID));
       try {
         uv = BRep_Tool::Parameters( V, F );
+        uvOK = true;
       }
       catch (Standard_Failure& exc) {
-        ok = false;
       }
-      if ( !ok ) {
+      if ( !uvOK ) {
-        for ( TopExp_Explorer vert(F,TopAbs_VERTEX); !ok && vert.More(); vert.Next() )
+        for ( TopExp_Explorer vert(F,TopAbs_VERTEX); !uvOK && vert.More(); vert.Next() )
-          ok = ( V == vert.Current() );
+          uvOK = ( V == vert.Current() );
-        if ( !ok ) {
+        if ( !uvOK ) {
 #ifdef _DEBUG_
           MESSAGE ( "SMESH_MesherHelper::GetNodeUV(); Vertex " << vertexID
                << " not in face " << GetMeshDS()->ShapeToIndex( F ) );
@@ -423,14 +403,14 @@ gp_XY SMESH_MesherHelper::GetNodeUV(const TopoDS_Face&   F,
           // get UV of a vertex closest to the node
           double dist = 1e100;
           gp_Pnt pn = XYZ( n );
-          for ( TopExp_Explorer vert(F,TopAbs_VERTEX); !ok && vert.More(); vert.Next() ) {
+          for ( TopExp_Explorer vert(F,TopAbs_VERTEX); !uvOK && vert.More(); vert.Next() ) {
             TopoDS_Vertex curV = TopoDS::Vertex( vert.Current() );
             gp_Pnt p = BRep_Tool::Pnt( curV );
             double curDist = p.SquareDistance( pn );
             if ( curDist < dist ) {
               dist = curDist;
               uv = BRep_Tool::Parameters( curV, F );
-              if ( dist < DBL_MIN ) break;
+              uvOK = ( dist < DBL_MIN );
             }
           }
         }
@@ -454,9 +434,58 @@ gp_XY SMESH_MesherHelper::GetNodeUV(const TopoDS_Face&   F,
         uv = GetUVOnSeam( uv, GetNodeUV( F, n2, 0 ));
     }
   }
+
+  if ( check )
+    *check = uvOK;
+
   return uv.XY();
 }
 
+//=======================================================================
+/*!
+ * \brief Check and fix node UV on a face
+ *  \retval bool - false if UV is bad and could not be fixed
+ */
+//=======================================================================
+
+bool SMESH_MesherHelper::CheckNodeUV(const TopoDS_Face&   F,
+                                     const SMDS_MeshNode* n,
+                                     gp_XY&               uv,
+                                     const double         tol) const
+{
+  if ( !myOkNodePosShapes.count( n->GetPosition()->GetShapeId() ))
+  {
+    // check that uv is correct
+    TopLoc_Location loc;
+    Handle(Geom_Surface) surface = BRep_Tool::Surface( F,loc );
+    gp_Pnt nodePnt = XYZ( n );
+    if ( !loc.IsIdentity() ) nodePnt.Transform( loc.Transformation().Inverted() );
+    if ( nodePnt.Distance( surface->Value( uv.X(), uv.Y() )) > tol )
+    {
+      // uv incorrect, project the node to surface
+      GeomAPI_ProjectPointOnSurf projector( nodePnt, surface, tol );
+      if ( !projector.IsDone() || projector.NbPoints() < 1 )
+      {
+        MESSAGE( "SMESH_MesherHelper::CheckNodeUV() failed to project" );
+        return false;
+      }
+      Quantity_Parameter U,V;
+      projector.LowerDistanceParameters(U,V);
+      if ( nodePnt.Distance( surface->Value( U, V )) > tol )
+      {
+        MESSAGE( "SMESH_MesherHelper::CheckNodeUV(), invalid projection" );
+        return false;
+      }
+      uv.SetCoord( U,V );
+    }
+    else if ( uv.Modulus() > numeric_limits<double>::min() )
+    {
+      ((SMESH_MesherHelper*) this)->myOkNodePosShapes.insert( n->GetPosition()->GetShapeId() );
+    }
+  }
+  return true;
+}
+
 //=======================================================================
 /*!
  * \brief Return middle UV taking in account surface period
@@ -583,10 +612,12 @@ const SMDS_MeshNode* SMESH_MesherHelper::GetMediumNode(const SMDS_MeshNode* n1,
         F = TopoDS::Face(myShape);
         faceID = myShapeID;
       }
+      bool uvOK1, uvOK2;
+      gp_XY p1 = GetNodeUV(F,n1,n2, &uvOK1);
+      gp_XY p2 = GetNodeUV(F,n2,n1, &uvOK2);
 
-      gp_XY p1 = GetNodeUV(F,n1,n2, &myCheckNodePos);
+      if ( uvOK1 && uvOK2 )
-      gp_XY p2 = GetNodeUV(F,n2,n1, &myCheckNodePos);
+      {
-
         if ( IsDegenShape( Pos1->GetShapeId() ))
           p1.SetCoord( myParIndex, p2.Coord( myParIndex ));
         else if ( IsDegenShape( Pos2->GetShapeId() ))
@@ -601,6 +632,7 @@ const SMDS_MeshNode* SMESH_MesherHelper::GetMediumNode(const SMDS_MeshNode* n1,
         myTLinkNodeMap.insert(make_pair(link,n12));
         return n12;
       }
+    }
     if (edgeID>0 || shapeType == TopAbs_EDGE) {
 
       TopoDS_Edge E;
@@ -611,8 +643,8 @@ const SMDS_MeshNode* SMESH_MesherHelper::GetMediumNode(const SMDS_MeshNode* n1,
         edgeID = myShapeID;
       }
 
-      double p1 = GetNodeU(E,n1, &myCheckNodePos);
+      double p1 = GetNodeU(E,n1);
-      double p2 = GetNodeU(E,n2, &myCheckNodePos);
+      double p2 = GetNodeU(E,n2);
 
       double f,l;
       Handle(Geom_Curve) C = BRep_Tool::Curve(E, f, l);

src/SMESH/SMESH_MesherHelper.hxx

@@ -151,15 +151,6 @@ public:
    */
   void SetElementsOnShape(bool toSet) { mySetElemOnShape = toSet; }
 
-  /*!
-   * \brief Enable/disable checking of node parameters on shapes while adding elements.
-   * In case of incorrect parameters mudium node place is computed as the middle
-   * of two nodes. Default is false.
-   * NOTE that this flag is reset to "not to check" if check with non-default partameter
-   * is successful
-   */
-  void SetCheckNodePosition(bool toCheck) { myCheckNodePos = toCheck; }
-
   /*!
    * \brief Set shape to make elements on without calling IsQuadraticSubMesh()
    */
@@ -260,6 +251,14 @@ public:
                   const SMDS_MeshNode* n,
                   const SMDS_MeshNode* inFaceNode=0,
                   bool*                check=0) const;
+  /*!
+   * \brief Check and fix node UV on a face
+   *  \retval bool - false if UV is bad and could not be fixed
+   */
+  bool CheckNodeUV(const TopoDS_Face&   F,
+                   const SMDS_MeshNode* n,
+                   gp_XY&               uv,
+                   const double         tol) const;
   /*!
    * \brief Return middle UV taking in account surface period
    */
@@ -393,7 +392,7 @@ protected:
   // to create quadratic elements
   bool            myCreateQuadratic;
   bool            mySetElemOnShape;
-  bool            myCheckNodePos;
+  std::set< int > myOkNodePosShapes;
 
 };