Logical ideas for displaying model assembly information

sunlin0oo
Fri, 12/22/2023 - 13:26

Forums:

Hi, everyone!

I have two questions. The first one is about assembly display.

I can read the assembly of the model through XDE, but I encountered a situation where when the assembly of the model only has 1, it will display the Solid or Compound of the model.ex:(CAD assistant display effect),Sometimes it will be the same number as Solid, and sometimes it will be different. I want to know why.

Another question is how do I get the number of Parts and what does Parts represent?

Thanks for your reply！

Dmitrii Pasukhin
Fri, 12/22/2023 - 13:53

Parts means assembly part. It is flexible parts that connected to the assembly root with some transfromation. It is not compound itself, it is assembly consturction.

  Handle(XCafDoc_ShapeTool) aShTool = ...;
  TDF_Label aLabel = ...;
  if (!aShTool ->IsAssembly(aLabel ))
  {
    return;
  }
  const int aNbComponents = aShTool->NbComponents (aLabel, false);
  TDF_LabelSequence aComponents;
  aShTool->GetComponents(aLabel, aComponents, false);

Best regards, Dmitrii.

sunlin0oo
Mon, 12/25/2023 - 06:55

Thanks for your reply!
I can read its root node a (0) through XDE. According to the code you provided, no assembly was detected, but in the CAD assistant it shows that it has 8 parts.

I traversed the related properties of Compounds and got the number to be 1.

Do you have any relevant thoughts and ideas?

I uploaded the model data. If necessary, you can download it for testing.
Looking forward to your reply again!

Attachments:

Product.iges

gkv311 n
Mon, 12/25/2023 - 09:41

The number you see is correct - this IGES model has only one object. What is confusing is CAD Assistant behavior - it implicitly expands document (XCAFDoc_Editor::Expand()) if it contains only a single root.

pload XDE VISIALIZATION
ReadIges D Product_0.iges
XExpand D 0; # that does the trick
vinit View1
XDisplay D -dispMode 1 -explore
vfit

Note that for preserving model structure it is better using STEP format instead of archaic IGES.

sunlin0oo
Mon, 12/25/2023 - 11:48

Thanks for your reply!

Due to my lack of technical knowledge, I do not understand what you are saying,There are a few points:

First, When you say that there is only one IGES object, you mean that the number of Compounds is one, right?

Second, According to your pseudocode, this is what I understand

// Creating empty XCAF document
    Handle(TDocStd_Document) anXdeDoc;
    Handle(TDocStd_Application) anXdeApp = new TDocStd_Application();
    anXdeApp->NewDocument("MDTV-XCAF", anXdeDoc);

    if (!aReader.Transfer(anXdeDoc))
    {
        std::cerr << "message from readIGES: "
            << "error" << std::endl;
        return false;
    }
    // Initialize an XDE Document (Shapes)==>GetRootsFromDocument
    TDF_Label aRootLabel = anXdeDoc->Main();
    XCAFDoc_Editor::Expand(aRootLabel);
    Handle(XCAFDoc_ShapeTool) ShapeTool = XCAFDoc_DocumentTool::ShapeTool(aRootLabel);
    TDF_LabelSequence rootLabels;
    ShapeTool->GetShapes(rootLabels);
    if (!aShapeTool->IsAssembly(aRootLabel))
    {
        return false;
    }
    const int aNbComponents = aShapeTool->NbComponents(aRootLabel, false);
    std::cout<<"aNbComponents" << aNbComponents << std::endl;

But, II still can't get the same number of Parts as in CAD assistant.

Last, The STEP model uses STEPCAFControl_Reader, and the IGES model uses IGESCAFControl_Reader. They should not affect each other, right?

Looking forward to your reply!

sunlin0oo
Wed, 12/27/2023 - 10:30

Thanks for your reply, now i can get assembly name. Next, I will continue to advance other work!