As I recommended above, you can try running vtkCleanPolyData just before vtkContourLoopExtraction, instead of running it on the output of the STL reader. Did you try this? It might be faster.
As I recommended above, you can try running vtkCleanPolyData just before vtkContourLoopExtraction, instead of running it on the output of the STL reader. Did you try this? It might be faster.