[vtkusers] Visualisation of PIV data

[Matthias Haack]

Hi Berk,

Berk Geveci wrote:
> The glyph filter (vtkGlyph2D and vtkGlyph3D) should do what you want. 
> You can use vtkGlyphSource2D and choose the type of arrow you want
> from that. 

I tried that today using a vtkGlyph3D and a vtkArrowSource as Source for 
the Glyph. But I only get vectors which lie within the plane even when 
the third component is not zero.

My vtkPolyData consists of a regular grid with a 3D vector at each point 
and so I'm rather surprised to see only arrows which lie within the 
plane. Maybe I'm making a mistake somewhere.


 > I would not use polydata to represent PIV data though.
> Since PIV data tends to be regularly sampled (unless you removed/cleaned
> a lot of vectors), vtkImageData (VTK's class that represents regular
> rectilinear data) should fit your needs best. 

I know but unfortunately I'm only doing the user-end visualization using 
a library which only understands vtkPolyData, e.g. I do not want to 
extend the library to use vtkImageData.

And besides, the vtkGlyph3D only gets vtkPolyData as input, doesn't it? 
(Maybe I could transform an image into vtkPolyData but that's not that 
easy for large datasets.)


 > I also
> recommend checking out ParaView (http://www.paraview.org). It is an
> end-user application built on top of VTK. We are in the process of
> releasing 1.0. By the way, VTK has a lot of image filters that can be
> very useful to process raw PIV image files.

I had a look at this site looks great and I'll give that a try in the 
future.


thanks a lot

Matthias