[vtkusers] Re: RES: [Paraview] VTK formats and Fortran (again...)

[Kent Eschenberg]

Renato N. Elias wrote:
 > However, there is no further information regarding such form of writing raw
 > binary data in "XML files" for VTK and PV. I'll try to write a file with raw
 > binary data in the AppendedData section to see what happen.

I worked with one of our users to modify their C program to directly write VTK 
XML-style files without using any VTK libraries. Its really not that hard and 
the format is well documented except for a detail or two. A single run of that 
application could generate over 100,000 of these VTK files, organized using a 
ParaView pvd file.

The "raw" binary format means just the machine's natural binary (that's what we 
used). The upside is that its as fast and compact as is possible. The downside 
is that the file will be unreadable on a machine that uses a different binary 
format. The XMl file supports a flag to indicate little-endian vs big-endian 
but you might be out of luck if there are other binary differences.

One of the details missing from the documentation (hello Kitware) is that the 
raw binary section must start with "length", a binary 32-bit integer that is 
the size of the following array of binary data:

    length = N * sizeof(type)

where N is the number of elements in the array and type is the type of data 
(int, short, float, double, ...).

Kent
Pittsburgh Supercomputing Center