[Paraview] how to utilize warp vector filter?

[Julian Cummings]

In my case, the displacement is a 2d vector in the radial direction (no
displacement along the tube).

I think I figured out a way to do what I want using the Calculator filter.
I am trying to replace the original radial position R with a new radial
position R' in which the displacement from the original radius R0 is
exaggerated by a scaling factor f>1.  Thus, R' = R0 + f*(R-R0).  Of course,
I am actually working in XYZ coordinates with R laying in the YZ plane.  So
one has to do a coordinate transformation of this equation, and I plugged
that into the Calculator filter to compute the new coordinates.  Now I can
see my displacements!

Thank you for all the suggestions and information on using the various
filters.
-- Julian C.


> -----Original Message-----
> From: Berk Geveci [mailto:berk.geveci at kitware.com] 
> Sent: Thursday, April 17, 2008 6:21 AM
> To: Julian Cummings
> Cc: paraview at paraview.org
> Subject: Re: [Paraview] how to utilize warp vector filter?
> 
> Is the displacement a vector or a scalar?
> 
> On Wed, Apr 16, 2008 at 9:51 PM, Julian Cummings 
> <cummings at cacr.caltech.edu> wrote:
> > 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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> >  > >
> >  >
> >
> >
> 
>