[vtkusers] Vectors in XML-format VTK files

[Deshpreet Singh Bedi]

Hi,

I have used legacy VTK file formats to view Vectors in other visualization
programs, such as VisIt.  The format I used was:

CELL_DATA 1
VECTORS Spin double
-0.449584 0.00705966 0.0459143

That should generate a vector at the center of the cell with vector
components vx, vy, vz given by the doubles above.  When I try to use the
same format in ParaView,  I run into a problem: instead of the desired
visualization, three vectors, each with the same direction and magnitude,
are shown.  I could not even get my vectors to be visualized correctly in
ParaView using the legacy format (even though it has worked in other
visualization programs), so I cannot yet use ParaView's in-built file-format
conversion functionality.  Any thoughts on what is going on?

Thanks,
Desh

On Wed, Oct 29, 2008 at 4:29 PM, Dominik Szczerba <dominik at itis.ethz.ch>wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Do you generate the file yourself (without VTK)? If so, I would start
> with something simpler as a legacy file. Then load it into PV, save as
> XML, and reverse-engineer the resulting file.
>
> Dominik
>
>
> Deshpreet Singh Bedi wrote:
> > Hi Dominik,
> >
> > Thanks for your reply.  One thing though -- what is the exact syntax for
> > including Vectors?  It is not precisely explained in the VTK File
> > Formats packet.  I want the Cell Data that I include to be visualized as
> > vectors originating from the center of my cells in ParaView.  How do I
> > specify that?
> >
> > Thanks,
> > Desh
> >
> > On Wed, Oct 29, 2008 at 3:52 PM, Dominik Szczerba <dominik at itis.ethz.ch
> > <mailto:dominik at itis.ethz.ch>> wrote:
> >
> > You can opt for immediate delivery and not a digest.
> >
> > If to use point or cell data is up to you and what you need.
> > Cell-centered scheme means you have data defined at cell center, in this
> > case the length of the array has to be that of the number of cells;
> > point-data means your data is defined at the points - in that case the
> > size of the array has to match the number of points.
> >
> > Dominik
> >
> > Deshpreet Singh Bedi wrote:
> >> Hi,
> >
> >> What is the best way to include vectors in XML-format VTK files?
> >  Should
> >> they be included as Cell Data or Point Data?  What is the difference,
> >> and what is the format for each?
> >
> >> Thanks,
> >
> >> Deshpreet Bedi
> >
> >> P.S. If possible, I would greatly appreciate it if a reply could be
> >> sent, in addition to the list-serve, directly to my email, as the
> > daily
> >> digest comes at far-too-widespread intervals.  Thank you.
> >
> >
> >
> > ------------------------------------------------------------------------
> >
> >> _______________________________________________
> >> This is the private VTK discussion list.
> >> Please keep messages on-topic. Check the FAQ at:
> > http://www.vtk.org/Wiki/VTK_FAQ
> >> Follow this link to subscribe/unsubscribe:
> >> http://www.vtk.org/mailman/listinfo/vtkusers
> >
>
> - --
> Dominik Szczerba, Ph.D.
> Computational Physics Group
> Foundation for Research on IT in Society
> http://www.itis.ethz.ch
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2.0.4-svn0 (GNU/Linux)
> Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org
>
> iD8DBQFJCMfE/EBMh9bUuzIRAsHPAJ0YtAdiSrdcgv3Qtt4mwBwt29M0SQCg2W9P
> 6NtJlMz4Mk7QHTUmlJsSPX4=
> =dVmk
> -----END PGP SIGNATURE-----
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20081029/9b1a6945/attachment.htm>