extract Ids of point subset from a give triangular surface
 

Dear All,

I am trying to extract indexs of a point subset from a given triangular surface.
Here are steps I am trying to do
(1) Import an VTK/STL triangular surface
(2) Filter->Generate IDS
(3) Extract points using "Select point on the surface"
(4) Filter->Extract Selections
(5) Filer->programmer filter to output the index for the subset.
Can somebody provide me a small script for the programmer fillter to output those Index?
Something like:
pdi = self.GetPolyDataInput();
pdo = self.GetPolyDataInput();
print():

Thanks a lot

Xudong

can somebody help me with this? many thanks in advance!