[vtkusers] Newbie: Large unstruktured grid (netcdf) and stream lines ...?!?

[Steffen.Kunze at dlr.de]

Hello

I hope someone understand my problem. Sorry for my bad english.

First the long version:
I am trying to visualise unstruktured grids given in netCDF. Unfortunatly there is no netCDF-reader given. (I am writing the programm with Python.) So I read the pointcoords and point-connections and put them into a vtkFloatArray and accordingly into a vtkCellArray. I create different CellArrays for surfacepoints and for "normal"-volumepoints because the amount of data is too big for displaying all polygons (using polydata.SetStrips()). So I want to use one polydata for the surface-polygons and another for all points - the given scalar-values are also belong to them.
My issue is to visualise the existing scalar-values with stream line and so on, but I have big problems to tell VTK how to create the stream line infos out of my data. In the vtk-examples I found some code, but it doesn´t work, because in the examples the data is read out of a file direcly.

Now the short code:
#here all! points are set
polydata.SetPoints(surf_points)
#this is for the surface-polygons
polydata.SetStrips(surf_strips)
#these are all points to which also the scalar-values belong to
volumepolydata.SetStrips(strips)

To produce stream lines I found code like this:
streamer = vtk.vtkStreamLine()
streamer.SetInputConnection(pl3d.GetOutputPort())

But I don´t have anything like pl3d.GetOutputPort() ! Do I ?!?

May someone please give me a hint want I can take as an input for the stream lines?

Thank You

Steffen