Programmable Filter Problem
 

Input: 722 Cells & 1200 Points
Programmable Filter:

def flatten(input, output):
# Copy the cells etc.
output.ShallowCopy(input)

input = self.GetInputDataObject(0, 0)
output = self.GetOutputDataObject(0)

if input.IsA("vtkMultiBlockDataSet"):
output.CopyStructure(input)
iter = input.NewIterator()
iter.UnRegister(None)
iter.InitTraversal()
while not iter.IsDoneWithTraversal():
curInput = iter.GetCurrentDataObject()
curOutput = curInput.NewInstance()
curOutput.UnRegister(None)
output.SetDataSet(iter, curOutput)
flatten(curInput, curOutput)
iter.GoToNextItem();
else:
flatten(input, output)

Output: 17265 Cells & 35681 Points

What is the Problem with the Programmable Filter ?