[Paraview] Getting data into Paraview to build 3D volume

[Dominik Szczerba]

Hi,

Lester Anderson wrote:
>   Hello Dominik
>  
> Thanks for the suggestion. I have seen various variants on the netCDF 
> importer but all require the paraview source code to be compiled, not 
> something I do personally. The problem with netCDF is that you end up 
> dealing with two variants, one which only accepts a single variable like 
> XYZ where z would be say elevation, and in effect you have a 2D layer. 
> The other variant is based on the COARDS convention and allows multiple 
> layers and variables to be built in to netCDF - this is not so easy to 
> construct.
>  
> It does seem that Paraview is great if you can get your data into a 
> suitable format, otherwise it seems to be a lot of effort. In that 
> respect, I do feel that having more generic import options, and a built 
> in netCDF option, would be a big benefit to users, particularly working 
> in geophysics.
>  
>  From reading the details on netCDF COARDS, writing a CDL file is the 
> way of simplifying the construction of a multi-scalar netCDF volume, but 
> clearly involves a lot of extra manipulation.
>  
> The thing to really ask is if you have a file giving a position in the 
> data volume (XYZ) and one or more scalar values at the given position, 
> in an ascii file (e.g. CSV) is there a simple way of getting the data 
> into Paraview as a true volume dataset?

certainly, you can convert such data to a format required by VTK volume 
data. see technical papers -> format specification somewhere on the vtk 
page how such file would have to look like.

I do think that support for cgns or netcdf would attract more people to 
Paraview. But as you say this is not trivial as such formats have 
structures, zones or layers in them. Good idea for a concrete project, 
just need to get funding.

-- Dominik

>  
> Thanks
>  
> Lester
> 
>  > Date: Sat, 2 Aug 2008 14:57:20 +0200
>  > From: dominik at itis.ethz.ch
>  > To: lester_anderson1963 at hotmail.com
>  > CC: paraview at paraview.org
>  > Subject: Re: [Paraview] Getting data into Paraview to build 3D volume
>  >
>  > How about writing an netCDF importer? I am not even sure if I haven't
>  > seen one reported on the list.
>  > -- Dominik
>  >
>  > Lester Anderson wrote:
>  > > Hello
>  > >
>  > > I know this is a very broad-based query but would like to get some
>  > > pointers. I normally work with GMT (netCDF) files but these at present
>  > > (at least in GMT) can only store one variable, e.g. lat, long, 
> elevation
>  > > or x,y,gravity etc. The latest netCDF convention does support
>  > > multi-scalar properties, and mult-levels via the COARDS convention, 
> this
>  > > however is not an export option in the latest GMT (4.3.1).
>  > >
>  > > My question is really one of how can I import data into Paraview to
>  > > generate a volume of data, as opposed to just a series of layers? As I
>  > > see it, I need to get the data into a format like XYZ (for position in
>  > > the volume) and then one or more variables to describe the scalar
>  > > function at the given position.
>  > >
>  > > Presently, I could export ascii XYZ data from GMT to generate say
>  > > x,y,gravity at level 0, and then x,y,gravity at level 1 etc...but it
>  > > does seem that Paraview expects the data in a more structured and
>  > > defined format, with which to generate a volume.
>  > >
>  > > There is a "roundabout" way to get netCDF files into Paraview via 
> VisIt
>  > > 1.9.0, and export as VTK, but this will only export things as simple
>  > > layers (XYZ), and not build a volume from a series of layers.
>  > >
>  > > I think it would be useful to at least have a in-depth tutorial guide
>  > > explaining how to get tabulated ascii data into Paraview and the
>  > > construction of data volumes from 2D information.
>  > >
>  > > If there are alternative methods of getting data into Paraview then 
> I'd
>  > > be interested to know.
>  > >
>  > > Thanks
>  > >
>  > > Lester
>  > >
>  > > Get fish-slapping on Messenger! Play Now
>  > > <http://clk.atdmt.com/UKM/go/101719805/direct/01/>
>  > >
>  > >
>  > > 
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>  >
>  > --
>  > Dominik Szczerba, Ph.D.
>  > Foundation for Research
>  > on Information Technologies in Society
>  > http://www.itis.ethz.ch
> 
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-- 
Dominik Szczerba, Ph.D.
Foundation for Research
on Information Technologies in Society
http://www.itis.ethz.ch