Visualizing magnetic field lines
For the ET MHD paper, I wanted to visualize magnetic field lines as done in figure 4 of DelZannaa 2002. For this I wanted to use VisIt on 2d hdf5 output (unigrid) from Carpet. The data and paremter files can be found in the MHD paper repository .
To visualize them, one has to do the "usual VisIt" stuff to get a vector into VisIt. Ie.
- open the file in VisIt
- create a new vector Expression (Control/Expressions...)
that combines the three components into a single vector (the precise names of the scalars differ from version to version in VisIt).
- add a "Streamline" plot and the "Project" operator
- set the streamline options as shown below
- you can find the full settings in the session file in the rotor repository 
- the final plot should look like this: