22772: EDF 8916 SMESH: Issue with a quadrangle mesh

Consider edges on period boundary as seam ones
This commit is contained in:
eap 2014-10-10 20:59:37 +04:00
parent e16f6412db
commit 65efd98e77
3 changed files with 115 additions and 107 deletions

View File

@ -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

View File

@ -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

View File

@ -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 );