[vtkusers] vtkCellArray and vtkPolyData

[Thinnes]

Hello vtkusers,

I have a strange problem. And I suppose the solution is really easy....

I try to set a vtkPolyData with a vtkCellArray (Each cell contain a 
tretrahedron.)using functions: SetPolys  and SetPoints
The problem is the vtkPolyData doesn't set.
And I get an error:
AttributeError: 'NoneType' object has no attribute 
'UpdateInformation'           

This is an simple example, in python, of what I want to do. If you run 
it, it will occur the error:
#*****************************************************
import vtk

# Generate the input points and constrained edges/polygons.
points = vtk.vtkPoints()
points.InsertPoint(0, 1, 4, 0)
points.InsertPoint(1, 3, 4, 0)
points.InsertPoint(2, 7, 4, 0)
points.InsertPoint(3, 11, 4, 0)
points.InsertPoint(4, 13, 4, 0)
points.InsertPoint(5, 13, 8, 0)
points.InsertPoint(6, 13, 12, 0)
points.InsertPoint(7, 10, 12, 0)
points.InsertPoint(8, 7, 12, 0)
points.InsertPoint(9, 4, 12, 0)
points.InsertPoint(10, 1, 12, 0)
points.InsertPoint(11, 1, 8, 0)
points.InsertPoint(12, 3.5, 5, 0)
points.InsertPoint(13, 4.5, 5, 0)
points.InsertPoint(14, 5.5, 8, 0)
points.InsertPoint(15, 6.5, 8, 0)
points.InsertPoint(16, 6.5, 5, 0)
points.InsertPoint(17, 7.5, 5, 0)
points.InsertPoint(18, 7.5, 8, 0)
points.InsertPoint(19, 9, 8, 0)
points.InsertPoint(20, 9, 5, 0)
points.InsertPoint(21, 10, 5, 0)
points.InsertPoint(22, 10, 7, 0)
points.InsertPoint(23, 11, 5, 0)
points.InsertPoint(24, 12, 5, 0)
points.InsertPoint(25, 10.5, 8, 0)
points.InsertPoint(26, 12, 11, 0)
points.InsertPoint(27, 11, 11, 0)
points.InsertPoint(28, 10, 9, 0)
points.InsertPoint(29, 10, 11, 0)
points.InsertPoint(30, 9, 11, 0)
points.InsertPoint(31, 9, 9, 0)
points.InsertPoint(32, 7.5, 9, 0)
points.InsertPoint(33, 7.5, 11, 0)
points.InsertPoint(34, 6.5, 11, 0)
points.InsertPoint(35, 6.5, 9, 0)
points.InsertPoint(36, 5, 9, 0)
points.InsertPoint(37, 4, 6, 0)
points.InsertPoint(38, 3, 9, 0)
points.InsertPoint(39, 2, 9, 0)
polys = vtk.vtkCellArray()
polys.InsertNextCell(12)
polys.InsertCellPoint(0)
polys.InsertCellPoint(1)
polys.InsertCellPoint(2)
polys.InsertCellPoint(3)
polys.InsertCellPoint(4)
polys.InsertCellPoint(5)
polys.InsertCellPoint(6)
polys.InsertCellPoint(7)
polys.InsertCellPoint(8)
polys.InsertCellPoint(9)
polys.InsertCellPoint(10)
polys.InsertCellPoint(11)
polys.InsertNextCell(28)
polys.InsertCellPoint(39)
polys.InsertCellPoint(38)
polys.InsertCellPoint(37)
polys.InsertCellPoint(36)
polys.InsertCellPoint(35)
polys.InsertCellPoint(34)
polys.InsertCellPoint(33)
polys.InsertCellPoint(32)
polys.InsertCellPoint(31)
polys.InsertCellPoint(30)
polys.InsertCellPoint(29)
polys.InsertCellPoint(28)
polys.InsertCellPoint(27)
polys.InsertCellPoint(26)
polys.InsertCellPoint(25)
polys.InsertCellPoint(24)
polys.InsertCellPoint(23)
polys.InsertCellPoint(22)
polys.InsertCellPoint(21)
polys.InsertCellPoint(20)
polys.InsertCellPoint(19)
polys.InsertCellPoint(18)
polys.InsertCellPoint(17)
polys.InsertCellPoint(16)
polys.InsertCellPoint(15)
polys.InsertCellPoint(14)
polys.InsertCellPoint(13)
polys.InsertCellPoint(12)

PolyData = vtk.vtkPolyData()
input = PolyData.SetPoints(points)
input = PolyData.SetPolys(polys)
input.UpdateInformation()
#**********************************************

I suppose I might not use these functions in the good way.
Could you help me please.

Bye
Alexandre