[vtkusers] how to create polydata with cell?

[qin]

Hi, all,

The way to use vtkPolyData in most  of the VTK examples  is to use
polydatareader.
In the examples, after the data  being read from vtk file, a serie of
VtkdataProcessor(filter) are applied.

1) Does the polydata coming from vtkfile  certainly have cells?
2) The polydata I created with vtkpoints and scalars But without creating
Cells seems to have no response to a lot of  vtkdataprocessor(filter).
3)  how to create   polydata with cells??

Thanks a lot.

qin