[vtkusers] calculate normal of boundary

[Fabian Braennstroem]

Hi,

I would like to use python-vtk to calculate the vector components of 
an inlet velocity for computational fluid dynamics.
For this I would have to read an ensight or vtk formated mesh and
calculate the normal direction of a certain boundary, e.g. 'inlet'.
Does anyone knows, if I can do this with python-vtk, or better, does
anyone has such a small script already? Would be nice :-)

Regards!
Fabian