[vtkusers] Why do I need Update()?

[Karin Faulhaber]

Hi,

I have the following Pipeline:

vtkPolyDataReader
vtkDelaunay2D
vtkPolyDataMapper

For days I was wondering and experimenting because I couldn't see
anything in my window. Since I incidentally asked the actor for an
attribute I can see my DEM. 
I don't understand that! When I put the vtkPolyDataReader output
directly to the mapper, I can see the points, with a filter between them
I don't. 
I thought I understood the Update thing ...

Any explanation is very much appreciated!!!
Karin


-- 
Karin Faulhaber
Universitaet Karlsruhe
Institut fuer Photogrammetrie und Fernerkundung (IPF)
Englerstr. 7 
76128 Karlsruhe

Tel: 0721/608-3676
E-Mail: faulhaber at ipf.uni-karlsruhe.de