[vtkusers] how to let vtkTubeFilter change radius by cell data?

[zxbo2004]

   Hi all:
       I want to generate tubes around polylines, and want to change the tube radius accord to certain values, that is one radius per line,  so I store those values in  cell data. To generate tube, I select vtkTubeFilter, but as far as I know vtkTubeFilter can only change radius accord to  point data, so how can I achive this purpose?
                                                                                                                 yours zxbo