[Fwd: Re: [vtkusers] Streamlines from scalars of structured points.Needing help!]

[Berk Geveci]

-----Forwarded Message-----

> From: Berk Geveci <berk.geveci at kitware.com>
> To: stefano mininel <mininel.ml at gnbts.univ.trieste.it>
> Subject: Re: [vtkusers] Streamlines from scalars of structured points.Needing  help!
> Date: 31 May 2002 07:09:57 -0400
> 
> > Thank you very much for your help.
> 
> No problem.
> 
> > Meanwhile, a question, just to have a general idea: am I correct if I think of the
> > vtkAssignAttribute filter as a sort of necessary interface between vtk4.0 data structures and the
> > classes/filters that expect in their input data in the way of older vtk versions (to call upon
> > such data the now deprecated xx->GetPointData()->GetVectors() or GetScalars()
> 
> Yes, you are wrong  :-) Although we removed the attribute classes like
> vtkVectors, vtkScalars etc., we haven't removed the _concept_ of attributes.
> GetVectors() is not deprecated. It just returns a vtkDataArray. Therefore
> filters still work on given attributes. Streamline filter has to find
> an assigned vector attribute (GetVectors()). All image filters, on the
> other hand, put their output in the scalar field. This is because of
> historical reasons. This is why you had to mark that array as the vectors.
> 
> -Berk
> 
>