Swarm viz with ParaView

[pgrete]

The documentation "Some visualization tools, like Visit and Paraview, prefer to have access to an id field for each " leads me to believe that our default hdf5 output allows particles to be visualized with ParaView.
Is there anything special I have to take care of (as I don't get the particles but I confirmed that they are in the hdf5 file).

ping @brryan @Yurlungur @AstroBarker

[Yurlungur]

I never got the particle XDMF to work properly. There are stubs for it in parthenon_xdmf.cpp, along with a preprocessor variable that you can set to on to enable them. At the time I asked parthenon folks if anyone had any ideas---no one did---and I reached out to the paraview and visit teams and never heard back from anybody about what was wrong, so I gave up.

If you wanted to take a look and see if you can get it working, an second pair of eyes would be very welcome!

[pgrete]

Ah, yes, I remember. Given that OpenPMD was made for particles, I'll focus my efforts on supporting particles there for now.

[Yurlungur]

The swarm HDF5 logic may be useful for OpenPMD as well, but yes that's where I'd focus