[Paraview] [Bug?] Transform Filter does not transform vectors in point data

[Moreland, Kenneth]

The transform filter will only transform the "active" normals and "active" vectors. The active normals are still used by ParaView and they appear to be transformed correctly. (To verify, create a sphere source, apply a rotate and/or asymmetric scale, and then add glyphs on the normals to see that they still point perpendicular to the surface.) The concept of active vectors is largely abandoned by ParaView. Instead, filters are expected to accept the names of variables to process.

Automatically transforming every field variable that happens to be a 3-tuple as a vector is a bad idea. There is no guarantee that each such variable is in fact a vector with meaning in the same space as the point coordinates. Thus, to properly implement this request, the transform filter should accept zero or more field variables to transform instead of just grabbing the active vectors.

As a workaround, one could use the calculator filter to apply the transform. Translates and scales are quite simple to implement, and rotations that are a factor of 90 degrees around any axis are pretty easy, too.



-Ken


________________________________
From: paraview-bounces at paraview.org [paraview-bounces at paraview.org] On Behalf Of Mengda Wu [phdggg at gmail.com]
Sent: Monday, July 21, 2008 10:19 PM
To: paraview at paraview.org
Subject: [Paraview] [Bug?] Transform Filter does not transform vectors in point data

Hi all,

   I have latest cvs version of Paraview running. I am using transform filter to transform the data set. I works fine with the point coordinates.
But the vectors in point data do not transform at all. I am wondering if this filter uses vtkTransformFilter<http://www.vtk.org/doc/nightly/html/classvtkTransformFilter.html> or vtkTransformPolyDataFilter<http://www.vtk.org/doc/nightly/html/classvtkTransformPolyDataFilter.html>.