[vtkusers] adding and deleting cells/triangles to a polydata

[Anders Wallin]

Hi group,
I have an algorithm that outputs triangles for an
animation/simulation[1]. For each new time-step the number of
triangles that change is a small number compared to the total number
of triangles. I would therefore not like to create a new polydata for
each time-step, but rather use the same polydata and delete some
cells/triangles, and add some new cells/triangles at each time-step.

I was looking here:
http://www.vtk.org/Wiki/VTK/Examples/Cxx/Broken/PolyData/DeletePoints
and here:
http://www.vtk.org/Wiki/VTK/Examples/Cxx/Broken/PolyData/Delete_cells

but both of these are in the "broken" category of examples.

Any ideas for how to do this easily/efficiently ?
To save memory I should probably delete old/unused points also, not only cells?

thanks,
Anders W
[1] something like this: http://www.youtube.com/watch?v=17mpgQ4KVLg