[Paraview] Problem reading/using STRUCTURED_GRID data

[Phil Goddard]

If I read you correctly then you're saying that using (or at least loading)
a custom color map is not recommended as it may lead to unexpected results.
That seems strange for a visualization package.

That being said, I have upgraded to the latest version, and the default
lookup table is fine for my initial purposes.

Thanks
Phil. 

> -----Original Message-----
> From: Moreland, Kenneth [mailto:kmorel at sandia.gov] 
> Sent: August 18, 2008 6:34 AM
> To: Phil Goddard; paraview at paraview.org
> Subject: RE: [Paraview] Problem reading/using STRUCTURED_GRID data
> 
> 
> First, let me recommend that you update your version of 
> ParaView (which you can download from www.paraview.org).  
> Version 2.4 was released several years ago and is no longer supported.
> 
> That said, I see that the behavior you describe also exists 
> in the latest released version (3.2).  It looks like the data 
> file is defining a lookup table with a domain from 0 to 1.  
> You can fix the problem by simply not defining a lookup table 
> for the data in the file.  Change the line "LOOKUP_TABLE lut" 
> to "LOOKUP_TABLE default" and the ParaView lookup table will 
> be used as expected.  You can also delete the entire 
> LOOKUP_TABLE section at the bottom of the file.
> 
> Why the lookup table defined in the file is scaling from 0 to 
> 1 and how to get past that, I don't know.  Personally, I 
> don't use this feature and don't recommend it to any ParaView 
> users because it has dubious value and usually leads to 
> confusing results (as you have just found).  If you really 
> care about this feature, you should bring it up with the 
> vtkusers list.
> 
> -Ken
> 
> > -----Original Message-----
> > From: paraview-bounces at paraview.org 
> > [mailto:paraview-bounces at paraview.org]
> > On Behalf Of Phil Goddard
> > Sent: Sunday, August 17, 2008 11:38 PM
> > To: paraview at paraview.org
> > Subject: [Paraview] Problem reading/using STRUCTURED_GRID data
> >
> >
> > I'm attempting to use Paraview for the first time, and 
> trying to get a 
> > feel for it by reading in a simple sample data set.
> > However the results are not as I expect and I'm wondering 
> if someone 
> > could give me some idea of what I am doing wrong.
> > I'm using version 2.4, release 4 from the CD that comes 
> with the VTK 
> > Users Guide (VTK 5.0.4) on Windows 2000.
> > My data file is appended below.
> >
> > From my understanding of my .vtk file I expect to see all points at 
> > z=0 as red, z=1 as green and z=2 as blue.
> > What I actually see is the points at z=1 being blue (z=0 
> and z=2 are 
> > red and blue respectively).
> >
> > If I use a probe to look at the data, those at z=1 seem to have a 
> > value of
> > 1
> > as I expect.
> >
> > If I change the Representation to Surface then the sides of 
> the cube 
> > have the colours
> > 0<red<0.33
> > 0.33<green<0.66
> > 0.66<blue<2
> >
> > Also, if I display the Scalar Bar and set its Resolution 
> property to 3 
> > then I get a Scalar Bar showing 0<blue<0.66<green<1.33<red<2.
> > This is the reverse of the lookup table that I have read in.
> >
> > So several questions:
> > 1. Why when viewed as points are those at z=1 not green?
> > 2. Why when viewed as a Surface do I get the colors described above?
> > 3. Why does the Scalar Bar have the colours reversed (from 
> what I expect)?
> >
> > Much appreciated
> > Phil.
> >
> >
> > %%%%%%%%%%%% CUT HERE %%%%%%%%%%%%%%%% # vtk DataFile 
> Version 2.0 Test 
> > data for a cube in 3D space ASCII
> >
> > DATASET STRUCTURED_GRID
> > DIMENSIONS 3 3 3
> > POINTS 27 float
> > 0 0 0
> > 1 0 0
> > 2 0 0
> > 0 1 0
> > 1 1 0
> > 2 1 0
> > 0 2 0
> > 1 2 0
> > 2 2 0
> > 0 0 1
> > 1 0 1
> > 2 0 1
> > 0 1 1
> > 1 1 1
> > 2 1 1
> > 0 2 1
> > 1 2 1
> > 2 2 1
> > 0 0 2
> > 1 0 2
> > 2 0 2
> > 0 1 2
> > 1 1 2
> > 2 1 2
> > 0 2 2
> > 1 2 2
> > 2 2 2
> >
> > POINT_DATA 27
> > SCALARS CubeData float 1
> > LOOKUP_TABLE lut
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 0.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 1.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > 2.0
> > LOOKUP_TABLE lut 3
> > 1.0 0.0 0.0 1.0
> > 0.0 1.0 0.0 1.0
> > 0.0 0.0 1.0 1.0
> > %%%%%%%%%%%% CUT HERE %%%%%%%%%%%%%%%%
> >
> >
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> 
> 
>