polygonal meshes do not get exported correctly to CGNS
Polygonal meshes do not get exported correctly to CGNS, at least in 1D. The coordinates and data look right, but there are no elements in the CGNS files. This can be reproduced by creating a line source and saving the result to CGNS. My guess is that each segment of the polygon will need to be split into individual BAR elements.
In particular, this means that streamtracer results cannot be saved to CGNS