[Paraview] how to utilize warp vector filter?

[Julian Cummings]

Hi Berk,

This got me a lot closer to where I want to be, but not quite there yet.
I want to magnify or exaggerate the very small ripples or displacements
on my tube, so I believe that I need to use the Warp (vector) filter
rather than the Glyph filter (which draws arrows rather than moving the
polygons).  I tried doing this, but the result looks strange...

I can see the displacements if I simply scale the Y and Z axes by a
factor of 100 (the X axis points along the tube in my geometry), but
then of course the tube appears squished.  I was hoping for a simple way
to enhance these radial displacements using ParaView filters.

-- Julian C.

On Wed, 2008-04-16 at 20:04 -0400, Berk Geveci wrote:
> Sometimes paraview can be confusing. Let me try to explain what you
> are seeing. Each object in the pipeline browser gets assigned a set of
> objects to visualize them. I am not going to go into a lot detail but
> the relevant object here is a filter that extracts geometry from the
> object (vtkDataSetSurfaceFilter). This filter converts any type of
> dataset to a set of polygons to be rendered by OpenGL. This may be an
> outline or the surface polygons. This filter also automatically
> generates normals. This is what you are seeing in the "Color By" menu.
> To duplicate this behavior, you can apply "Extract Surface" and then
> "Generate Surface Normals". Then you can apply the glyph filter.
> Orient by the normals and scale by scalars.
> 
> -berk
> 
> On Wed, Apr 16, 2008 at 3:57 PM, Julian Cummings
> <cummings at cacr.caltech.edu> wrote:
> > Hello,
> >
> >  I have a set of scalar data on an unstructured grid representing
> >  effective stress on a cylindrical tube.  I would like to use the warp
> >  vector filter to exaggerate the displacement of the tube surface.  It
> >  appears that I need to have the cell normals available as a data array
> >  in order to scale the displacement and make it more visible.  How do I
> >  do this?  When I load my unstructured grid data set, neither the Normals
> >  Generation filter nor the Warp (vector) filter is available.  ParaView
> >  is able to color the tube using cell normal as an attribute, but there
> >  does not seem to be a way to extract this attribute and use it for the
> >  warp vector filter.  Any advice would be appreciated.
> >
> >  Thanks, Julian C.
> >
> >  --
> >  Dr. Julian C. Cummings                       E-mail: cummings at cacr.caltech.edu
> >  California Institute of Technology           Phone:  626-395-2543
> >  1200 E. California Blvd., Mail Code 158-79   Fax:    626-584-5917
> >  Pasadena, CA 91125                           Office: 125 Powell-Booth
> >
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>