Method BuildPolyDataFromSkin

IO/Geometry/vtkGLTFDocumentLoader.cxx:1285–1361

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//------------------------------------------------------------------------------
bool vtkGLTFDocumentLoader::BuildPolyDataFromSkin(Skin& skin)
{
  if (skin.Skeleton >= 0 && skin.Skeleton < static_cast<int>(this->InternalModel->Nodes.size()))
  {
    skin.Armature = vtkSmartPointer<vtkPolyData>::New();

    vtkNew<vtkPoints> points;
    points->SetNumberOfPoints(skin.Joints.size());

    vtkNew<vtkCellArray> vertices;

    std::vector<int> nodeMapping(this->InternalModel->Nodes.size(), -1);

    for (size_t i = 0; i < skin.Joints.size(); i++)
    {
      if (skin.Joints[i] >= static_cast<int>(nodeMapping.size()))
      {
        // invalid index
        return false;
      }

      double p[3] = {};

      auto trs = this->InternalModel->Nodes[skin.Joints[i]].GlobalTransform;
      if (trs)
      {
        p[0] = trs->GetElement(0, 3);
        p[1] = trs->GetElement(1, 3);
        p[2] = trs->GetElement(2, 3);
      }

      points->SetPoint(i, p);

      vtkIdType vId = i;
      vertices->InsertNextCell(1, &vId);

      nodeMapping[skin.Joints[i]] = static_cast<int>(i);
    }

    vtkNew<vtkCellArray> lines;

    std::function<bool(int)> VisitJoint = [&](int nodeIndex)
    {
      const Node& node = this->InternalModel->Nodes[nodeIndex];

      int mappedNode = nodeMapping[nodeIndex];

      if (mappedNode == -1)
      {
        return false;
      }

      for (int childIndex : node.Children)
      {
        int mappedChild = nodeMapping[childIndex];

        if (mappedChild == -1)
        {