[vtkusers] VTK data files and formats...

[Terry J. Ligocki]

I have been using, creating, and reading VTK data files (especially Poly
Data, Structured Points, and Structured Grids) for some time now and I
have one major question/comment:

Is there any way in the current format to reference data in another file
(short of replicating that data in the current file - which isn't a
reference anyway, :-)?

For example, I have a file with (x,y,z) coordinates for a Structured
Grid and hundreds of time steps of scalar data.  The coordinates don't
change with time.  Currently, I seem to have one of two choices:

   * Create a Structured Grid file for each time step with a copy of the
     (x,y,z) coordinates and the data - this creates a lot of redundant
     data (the coordinates) and increases the size of the data set by
     about a factor of 4.

   * Create a Structured Grid file for the coordinates with no data,
     create a Structured Points file for each time step with the data,
     read the Structured Grid once, and for each time step read the a
     Structured Points and set the Structured Grid's point data to the
     Structured Points' point data.  This is what I do and it works but
     it seems a little weird, :-).

Also, in general, I often have "raw" ASCII or binary data (meaning data
or coordinates with no dimensional information) available in some files
and I'd like to generate a VTK file which references this data without
concatenating everything together into one file.  Basically, I'd like to
be able to "include" other files in a VTK data file.  It could, of
course, be made more complex but this would be enough to cover most of
the things I have come across.

Is something like this already possible?  If not, I'd be interested to
helping add it but I wanted to make sure it wasn't already possible and
then to discuss how to implement it.  I think it would be a good idea to
add a very simple extension and then think/worry about more
sophisticated extensions.

That's all for now...

                Terry J. (Ligocki, tjligocki at lbl.gov, (510)486-6140)
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