Output of point data to VTK and NetCDF

[jpthiele]

For finite element codes (ultimately based on T8code.jl) we would like to try incorporating t8code.
Naturally the results would be point/vertex based and not element based in most cases.

The solution would be to introduce an additional point data type and matching function calls.
For code deduplication it would probably be worthwhile to have a full feature function that can output both
that gets called by the current function for only element data internally.

The alternative would be to implement the vtk output of the parallel mesh and point data in Julia directly,
but that would duplicate most of the code from t8code.

"Priority: medium"

[Davknapp]

Hey @jpthiele

thank you for submitting this Issue. I just want to double check if I understand your Issue correctly.
Do you want to write out point-data to a VTK/NetCDF-file, or do you want to store data per point, that will be managed by t8code and eventually written to a VTK/NetCDF-file?

[jpthiele]

Ultimately results would be stored in a distributed linear algebra vector anyways so I don't think the second option would be needed in our code.
Practically, I would like a 'sibling function' for t8_forest_write_vtk_ext where I can also provide point data.

[Davknapp]

Hey @jpthiele ,

in our current version of our vtk-writer we duplicate the points of our mesh by the number of elements that share this point. A quick introduction of your feature-proposal would also mean to duplicate the data of the points, probably resulting in a messy output.
We are currently working on a unique point-id, but it will take some time. Therefore a proper implementation of your feature-proposal will take some time, even though we think that it is a nice idea.
We will keep this issue open, but on our low-priority list and solve it eventually.