void STEPCAFControl_Reader::ExpandShell(const Handle(StepShape_ConnectedFaceSet)& Shell,
  TDF_Label& RootLab,
  const Handle(Transfer_TransientProcess)& TP,
  const Handle(XCAFDoc_ShapeTool)& ShapeTool) const
{
  // Record CAF data
  SettleShapeData(Shell, RootLab, ShapeTool, TP);

  // Access faces
  Handle(StepShape_HArray1OfFace) aFaces = Shell->CfsFaces();
  for (Standard_Integer f = aFaces->Lower(); f <= aFaces->Upper(); ++f)
  {
    const Handle(StepShape_Face)& aFace = aFaces->Value(f);
    if (aFace.IsNull())
      continue;

    // Record CAF data
    SettleShapeData(aFace, RootLab, ShapeTool, TP);

    // Access face bounds
    Handle(StepShape_HArray1OfFaceBound) aWires = aFace->Bounds();
    if (aWires.IsNull())
      continue;
    for (Standard_Integer w = aWires->Lower(); w <= aWires->Upper(); ++w)
    {
      const Handle(StepShape_Loop)& aWire = aWires->Value(w)->Bound();

      // Record CAF data
      SettleShapeData(aWire, RootLab, ShapeTool, TP);

      // Access wire edges
      // Currently only EDGE LOOPs are considered (!)
      if (!aWire->IsInstance(STANDARD_TYPE(StepShape_EdgeLoop)))
        continue;

      // Access edges
      Handle(StepShape_EdgeLoop) anEdgeLoop = Handle(StepShape_EdgeLoop)::DownCast(aWire);
      Handle(StepShape_HArray1OfOrientedEdge) anEdges = anEdgeLoop->EdgeList();
      for (Standard_Integer e = anEdges->Lower(); e <= anEdges->Upper(); ++e)
      {
        Handle(StepShape_OrientedEdge) anOrientedEdge = anEdges->Value(e);
        if (anOrientedEdge.IsNull())
          continue;
        Handle(StepShape_Edge) anEdge = anOrientedEdge->EdgeElement();
        if (anEdge.IsNull())
          continue;

        // Record CAF data
        SettleShapeData(anEdge, RootLab, ShapeTool, TP);

        // Access vertices
        Handle(StepShape_Vertex) aV1 = anEdge->EdgeStart();
        Handle(StepShape_Vertex) aV2 = anEdge->EdgeEnd();

        // Record CAF data
        if (aV1.IsNull()==false)
            SettleShapeData(aV1, RootLab, ShapeTool, TP);
        if (aV2.IsNull()==false)
            SettleShapeData(aV2, RootLab, ShapeTool, TP);
      }
    }
  }
}

//=======================================================================
//function : SettleShapeData
//purpose  :
//=======================================================================

TDF_Label STEPCAFControl_Reader_priv::SettleShapeData(const Handle(StepRepr_RepresentationItem)& theItem,
  const TDF_Label& theLab,
  const Handle(XCAFDoc_ShapeTool)& theShapeTool,
  const Handle(Transfer_TransientProcess)& TP) const
{
  TDF_Label aResult = theLab;
  if (theItem.IsNull())
    return aResult;

  Handle(TCollection_HAsciiString) hName = theItem->Name();
  if (hName.IsNull() || hName->IsEmpty())
    return aResult;

  Handle(Transfer_Binder) aBinder = TP->Find(theItem);
  if (aBinder.IsNull())
    return aResult;

  TopoDS_Shape aShape = TransferBRep::ShapeResult(aBinder);
  if (aShape.IsNull())
    return aResult;

  // Allocate sub-Label
  aResult = theShapeTool->AddSubShape(theLab, aShape);
  if (aResult.IsNull())
    return aResult;

  TCollection_AsciiString aName = hName->String();
  TDataStd_Name::Set(aResult, aName);
  theShapeTool->SetShape(aResult, aShape);

  return aResult;
}