Disconnected faces after connected components

[zandarina]

Hello, I found a weird behaviour after applying a subtraction using your library.

I am trying to subtract two polydatas and if i do not apply connected components, the result looks ok, but if I apply the connected components filter to get the largest region, the result is a small subset of faces of what it should be the whole component. I show this issue in images

Result of the boolean subtraction without connected components is ok

Result of the boolean subtraction with connected components fails

The code seems ok to me. So I wonder if it is a bug in the way to connect faces. I wonder if there is a way to solve this issue.

     vtkSmartPointer<vtkTriangleFilter> tri1 =
        vtkSmartPointer<vtkTriangleFilter>::New();
    tri1->SetInputData(splint);
    vtkSmartPointer<vtkCleanPolyData> clean1 =
        vtkSmartPointer<vtkCleanPolyData>::New();
    clean1->SetInputConnection(tri1->GetOutputPort());
    clean1->Update();
    vtkSmartPointer<vtkStripper> strip1 =
        vtkSmartPointer<vtkStripper>::New();
    strip1->SetInputConnection(clean1->GetOutputPort());
    strip1->Update();
    vtkNew<vtkPolyDataNormals> normal1;
    normal1->SetInputData(strip1->GetOutput());
    normal1->ComputePointNormalsOn();
    normal1->ComputeCellNormalsOff();
    normal1->Update();
    auto input1 = normal1->GetOutput();

    vtkSmartPointer<vtkTriangleFilter> tri2 =
        vtkSmartPointer<vtkTriangleFilter>::New();
    tri2->SetInputData(polydataToSubstractToSplint);
    tri2->Update();
    vtkSmartPointer<vtkCleanPolyData> clean2 =
        vtkSmartPointer<vtkCleanPolyData>::New();
    clean2->SetInputConnection(tri2->GetOutputPort());
    clean2->Update();
    vtkSmartPointer<vtkStripper> strip2 =
        vtkSmartPointer<vtkStripper>::New();
    strip2->SetInputConnection(clean2->GetOutputPort());
    strip2->Update();
    vtkNew<vtkPolyDataNormals> normal2;
    normal2->SetInputData(strip2->GetOutput());
    normal2->ComputePointNormalsOn();
    normal2->ComputeCellNormalsOff();
    normal2->Update();
    auto input2 = normal2->GetOutput();
    vtkPolyDataBooleanFilter *bf2 = vtkPolyDataBooleanFilter::New();
    bf2->SetInputData(0, input1);
    bf2->SetInputData(1, input2);
    bf2->SetOperModeToDifference();
    try {
        bf2->Update();
    }

I attach some polydatas for testing in case this issue is unknown.

https://we.tl/t-STIpdaCFNQ

Thanks

[zandarina]

Any idea? Is it a problem of the library?

[zippy84]

My answer is very late, but do you still need help on this? Otherwise I would close the issue.