Problem ith tessellation(no smoothing surface)

Hello

I want to tessellate a shape loaded from a step file. My problem that I found many faces NULL which can't be tessellated. I reduce the value of deflection but also i have some faces null. The code used as below :

qDebug()<<"begin tesselation"<<endl;

Standard_Real aDeflection = 1e-6;

Standard_Real angularDeflection=1e-6;

Standard_Integer aNumOfFace = 1;

Standard_Integer aNumOfEdge = 2;

 

 

//==========================================================================

 

BRepTools::Clean(aShape);

BRepMesh_IncrementalMesh(aShape,aDeflection,angularDeflection);

 

BRep_Builder aBuilder,aBuild1,aBuild2;

TopoDS_Compound aCompound,aComp1,aComp2;

aBuilder.MakeCompound(aCompound);

aBuild1.MakeCompound(aComp1);

aBuild2.MakeCompound(aComp2);

 

TopTools_SequenceOfShape aVertices;

Standard_Integer aCount = 0;

Standard_Integer aNumOfNodes = 0;

Standard_Integer aNumOfTriangles = 0;

 

 

TopExp_Explorer aExpFace,aExpEdge;

 

for(aExpFace.Init(aShape,TopAbs_FACE);aExpFace.More();aExpFace.Next())

{

aCount++;

 

TopoDS_Face aFace = TopoDS::Face(aExpFace.Current());

TopLoc_Location aLocation;

 

Handle_Poly_Triangulation aTr = BRep_Tool::Triangulation(aFace,aLocation);

 

if(!aTr.IsNull())

{

const TColgp_Array1OfPnt& aNodes = aTr->Nodes();

aNumOfNodes += aTr->NbNodes();

//Standard_Integer aLower = aNodes.Lower();

//Standard_Integer anUpper = aNodes.Upper();

const Poly_Array1OfTriangle& triangles = aTr->Triangles();

aNumOfTriangles += aTr->NbTriangles();

 

if(aCount == aNumOfFace)

{

Standard_Integer aNbOfNodesOfFace = aTr->NbNodes();

Standard_Integer aNbOfTrianglesOfFace = aTr->NbTriangles();

aExpEdge.Init(aFace,TopAbs_EDGE);

 

TopoDS_Edge aEdge;

 

for( Standard_Integer i = 0; aExpEdge.More() && i < aNumOfEdge ; aExpEdge.Next(), i++)

aEdge = TopoDS::Edge(aExpEdge.Current());

 

if(!aEdge.IsNull())

{

Handle_Poly_PolygonOnTriangulation aPol =

BRep_Tool::PolygonOnTriangulation(aEdge,aTr,aEdge.Location());

 

if(!aPol.IsNull())

{

const TColStd_Array1OfInteger& aNodesOfPol = aPol->Nodes();

Standard_Integer aNbOfNodesOfEdge = aPol->NbNodes();

 

Standard_Integer aLower = aNodesOfPol.Lower(), anUpper = aNodesOfPol.Upper();

for( int i = aLower; i < anUpper ; i++)

{

gp_Pnt aPnt1 = aNodes(aNodesOfPol(i)).Transformed(aLocation);

gp_Pnt aPnt2 = aNodes(aNodesOfPol(i+1)).Transformed(aLocation);

TopoDS_Vertex aVertex1 = BRepBuilderAPI_MakeVertex (aPnt1);

TopoDS_Vertex aVertex2 = BRepBuilderAPI_MakeVertex (aPnt2);

 

if(!aVertex1.IsNull() && !aVertex2.IsNull() && // if vertices are "alive"

!BRep_Tool::Pnt(aVertex1).IsEqual(

BRep_Tool::Pnt(aVertex2),Precision::Confusion())) // if they are different

{

aEdge = BRepBuilderAPI_MakeEdge (aVertex1,aVertex2);

aBuild2.Add(aComp2,aVertex1);

if(!aEdge.IsNull())

aBuild2.Add(aComp2,aEdge);

if(i == anUpper-1)

aBuild2.Add(aComp2,aVertex2);

}

}

}

}

}

 

 

TopTools_DataMapOfIntegerShape aEdges;

TopTools_SequenceOfShape aVertices;

 

for( Standard_Integer i = 1; i < aNodes.Length()+1; i++)

{

gp_Pnt aPnt = aNodes(i).Transformed(aLocation);

TopoDS_Vertex aVertex = BRepBuilderAPI_MakeVertex(aPnt);

 

if(!aVertex.IsNull())

{

aBuilder.Add(aCompound,aVertex);

if(aCount == aNumOfFace )

aBuild1.Add(aComp1,aVertex);

aVertices.Append(aVertex);

}

}

 

Standard_Integer nnn = aTr->NbTriangles();

//aNodes=aTr->Nodes();

Standard_Integer nt,n1,n2,n3;

 

for( nt = 1 ; nt < nnn+1 ; nt++)

{

triangles(nt).Get(n1,n2,n3);

gp_Pnt v1 = aNodes(n1);

gp_Pnt v2 = aNodes(n2);

gp_Pnt v3 = aNodes(n3);

mesh->addFace(QVector3D(v1.X(),v1.Y(),v1.Z()),QVector3D(v2.X(),v2.Y(),v2.Z()),QVector3D(v3.X(),v3.Y(),v3.Z()));

 

 

Standard_Integer key[3];

 

TopoDS_Vertex aV1,aV2;

key[0] = _key(n1, n2);

if(!aEdges.IsBound(key[0]))

{

aV1 = TopoDS::Vertex(aVertices(n1));

aV2 = TopoDS::Vertex(aVertices(n2));

if(!aV1.IsNull() && !aV2.IsNull() &&

!BRep_Tool::Pnt(aV1).IsEqual(BRep_Tool::Pnt(aV2),Precision::Confusion()))

{

TopoDS_Edge aEdge = BRepBuilderAPI_MakeEdge (aV1,aV2);

if(!aEdge.IsNull())

{

aEdges.Bind(key[0], aEdge);

aBuilder.Add(aCompound,aEdges(key[0]));

if(aCount == aNumOfFace)

aBuild1.Add(aComp1,aEdges(key[0]));

}

}

}

 

key[1] = _key(n2,n3);

if(!aEdges.IsBound(key[1]))

{

aV1 = TopoDS::Vertex(aVertices(n2));

aV2 = TopoDS::Vertex(aVertices(n3));

if(!aV1.IsNull() && !aV2.IsNull() &&

!BRep_Tool::Pnt(aV1).IsEqual(BRep_Tool::Pnt(aV2),Precision::Confusion()))

{

TopoDS_Edge aEdge = BRepBuilderAPI_MakeEdge (aV1,aV2);

if(!aEdge.IsNull())

{

aEdges.Bind(key[1],aEdge);

aBuilder.Add(aCompound,aEdges(key[1]));

if(aCount == aNumOfFace)

aBuild1.Add(aComp1,aEdges(key[1]));

}

}

}

 

key[2] = _key(n3,n1);

if(!aEdges.IsBound(key[2]))

{

aV1 = TopoDS::Vertex(aVertices(n3));

aV2 = TopoDS::Vertex(aVertices(n1));

if(!aV1.IsNull() && !aV2.IsNull() &&

!BRep_Tool::Pnt(aV1).IsEqual(BRep_Tool::Pnt(aV2),Precision::Confusion()))

{

TopoDS_Edge aEdge = BRepBuilderAPI_MakeEdge (aV1,aV2);

if(!aEdge.IsNull())

{

aEdges.Bind(key[2],aEdge);

aBuilder.Add(aCompound,aEdges(key[2]));

if(aCount == aNumOfFace)

aBuild1.Add(aComp1,aEdges(key[2]));

}

}

}

}

 

if(aCount == aNumOfFace)

{

qDebug()<<"aCount == aNumOfFace"<<endl;

}

}

else

{

qDebug()<<"face NULL"<<endl;

}

}

Thank you very much for your help