Method ClipPolyData

Filters/General/vtkTableBasedClipDataSet.cxx:1448–1475

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void vtkTableBasedClipDataSet::ClipPolyData(vtkPolyData* inputGrid,
  vtkImplicitFunction* implicitFunction, vtkDoubleArray* scalars, double isoValue,
  vtkUnstructuredGrid* outputUG)
{
  // check if it's easily convertible to vtkUnstructuredGrid
  auto polyData = vtkPolyData::SafeDownCast(inputGrid);
  if (vtkPolyDataToUnstructuredGrid::CanBeProcessedFast(polyData))
  {
    // convert to vtkUnstructuredGrid
    //
    // It's beneficial to convert a polydata to unstructured grid for clipping because the
    // GetCellType and GetCellPoints are the most expensive functions used (excluding point/cell
    // data related functions). The vtkPolyData ones are more expensive than the vtkUnstructuredGrid
    // ones because they perform a bit operation to get the cell type and then based on that, get
    // the correct cell array and extract the cell points. This overhead turns out to increase the
    // execution time by 10%-20%.
    vtkNew<vtkPolyDataToUnstructuredGrid> converter;
    converter->SetInputData(polyData);
    converter->SetContainerAlgorithm(this);
    converter->Update();
    auto uGrid = converter->GetOutput();
    this->ClipTDataSet(uGrid, implicitFunction, scalars, isoValue, outputUG);
  }
  else
  {
    this->ClipTDataSet(inputGrid, implicitFunction, scalars, isoValue, outputUG);
  }
}

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template <class TGrid>