triangulation problems with some igs file

Hi all,

I'am a beginner, please help me..
my objectif is to import a .igs file and triangulate it, so i try to use three functions:

1- ImportIges(string filename);

2- FacesFromCompounds (const TopoDS_Shape &Shape, std::vector &topoFaceVector);

3- Triangulation_Occ();// in the function,i do three for loop:

FacesFromCompounds(aisShape->Shape(),face_vector);

for(fit=face_vector.begin();fit!=face_vector.end();fit++)
{
if((!fit->IsNull())&&(fit->ShapeType()==TopAbs_FACE))
{

BRepMesh::Mesh(*fit,0.01);

//...............//

for (TopExp_Explorer ex(*fit,TopAbs_FACE); ex.More(); ex.Next())
{ TopoDS_Face myFace = TopoDS::Face(ex.Current());
//.......//
if (!myFace.IsNull()) {
Handle(Poly_Triangulation) myT = BRep_Tool::Triangulation(myFace, L);
//........//

const TColgp_Array1OfPnt& Nodes = myT->Nodes();
const TColgp_Array1OfPnt2d& UVNodes = myT->UVNodes();
const Poly_Array1OfTriangle& triangles = myT->Triangles();
//......//
if (myT->HasUVNodes())
{
//......//
for (int i = 1; i {

Poly_Triangle mytriangle = triangles.Value(i);
//....//
triangle_vector.push_back(Tri);
//......//
}
}

}
} }

}

I'm facing a problem triangulating faces with some IGS file( wich have a lot of faces ).Does anybody have any suggestions or solutions?

Thank you very much in advance.