VisIt is a very powerful visualization tool package developed at the Lawrence Livermore National Laboratory (LLNL). It was selected by the Drexel BASIN group as the official plotting package.
The official VisIt web site contains full documentation on the package. In particular it describes how to "Get Data into VisIt". This can be done via the use of a variety of standard data formats that VisIt understands, by writing new specialized readers, or by instrumenting your simulation code to interact with VisIt.
The VisIt distribution kit comes with sample graphic data files. Go
to /usr/local/visit/data/ and practice using the
interactive visualization tool. The latter is evoked by
/usr/local/visit/bin/visit.
One of the file format supported by VisIt is
VTK. The VisIt distribution kit comes with "writer" codes
that allow to write data in this format. These functions are
distributed as a C code and header file labeled
visit_writer.c and visit_writer.h
respectively.
The tarball
Mandelbrot_VTK.tar.gz
expands in a directory containing modified examples from the VisIt web
site and the display of the Mandelbrot set from a serial code. Compile
and run these examples to create .vtk files that are
readable by VisIt.