Regroup shapes under one parent assembly

[Lingkan]

Hello, I'm reading multiple shapes using STEPCAFControl_Reader API into the document which results in several shapes being created under root.

Main()
|- shape_1
|- shape_2
|- shape_...

Now I want to regroup these shapes under one parent assembly knot:

Main()
|- MyParentAssembly
|- shape_1
|- shape_2
|- shape_...

For now i tried to collect the shapes into a compound which sort of works, but seems to copy the shapes into a new assmbly instead of regrouping them. Also properties like color and name aren't preserved using this approach (see attached pictures).

1. Read Shapes into document (applying transformation and color)

bool App::LoadSTEPWithTransformAndColor(
    const std::string& filename, const gp_Trsf& transformation,
    const std::string& colorStr) {
  // Record the state before transfer
  std::set<std::string, std::less<>> existingShapes;
  TDF_LabelSequence allShapesBefore;
  Handle(XCAFDoc_ShapeTool) ST = m_doc->GetShapeTool();
  ST->GetFreeShapes(allShapesBefore);
  for (Standard_Integer i = 1; i <= allShapesBefore.Length(); i++) {
    TDF_Label label = allShapesBefore.Value(i);
    TCollection_AsciiString entry;
    TDF_Tool::Entry(label, entry);
    existingShapes.emplace(entry.ToCString());
  }

  // Perform the transfer
  if (!m_doc->LoadSTEP(filename)) {
    return false;
  }

  // Identify new shapes
  TDF_LabelSequence allShapesAfter;
  ST->GetFreeShapes(allShapesAfter);
  for (Standard_Integer i = 1; i <= allShapesAfter.Length(); i++) {
    TDF_Label label = allShapesAfter.Value(i);
    TCollection_AsciiString entry;
    TDF_Tool::Entry(label, entry);
    if (existingShapes.find(entry.ToCString()) == existingShapes.end()) {
      // This is a new shape
      TopoDS_Shape shape = XCAFDoc_ShapeTool::GetShape(label);
      // ... apply transformation ...
      BRepBuilderAPI_Transform brepTrsf(shape, transformation);
      TopoDS_Shape transformedShape = brepTrsf.Shape();
      // ... add color ...
      if (!colorStr.empty()) {
        Quantity_ColorRGBA color;
        Quantity_ColorRGBA::ColorFromHex(colorStr.c_str(), color);
        m_doc->SetColor(label, color, true);
      }
      // ... and add it to the document
      ST->SetShape(label, transformedShape);
    }
  }

  return true;
}

2. Try regroup

Handle(XCAFDoc_ShapeTool) ST = m_doc->GetShapeTool();
TDF_LabelSequence labels;
ST->GetFreeShapes(labels);

TopoDS_Compound C;
BRep_Builder B;
B.MakeCompound(C);
for (int i = 1; i <= labels.Length(); ++i) {
    TopoDS_Shape const& S = XCAFDoc_ShapeTool::GetShape(labels(i));
    B.Add(C, S);
}
ST->AddShape(C, true);

I appreciate your help!

 

[Lingkan]

I resolved this issue by not setting the shape in the `LoadSTEPWithTransformAndColor()` and instead collecting all the shapes and add them alltogether afterwards.