plex.pointSF.ilocal is an array of leaf points on each rank. If the array is trivial (i.e., ilocal = [0, 1, 2, ...]), ilocal is set to NULL. So typically we use this array as point = ilocal[i] if ilocal else i, but in some places we simply do point = ilocal[I]. This is fine if a rank at least owns one cell (ilocal is nontrivial due to plex point numbering convention) or does not have cells at all, but not fine if the rank sees and only sees ghost cells (ilocal is trivial, so ilocal becomes NULL) . It turned out that we need to handle the latter case if submeshes are involved the submesh PR.
ksagiyam
commented
2 months ago
Allow for ghost only meshes.
plex.pointSF.ilocalis an array of leaf points on each rank. If the array is trivial (i.e.,ilocal = [0, 1, 2, ...]),ilocalis set toNULL. So typically we use this array aspoint = ilocal[i] if ilocal else i, but in some places we simply dopoint = ilocal[I]. This is fine if a rank at least owns one cell (ilocalis nontrivial due to plex point numbering convention) or does not have cells at all, but not fine if the rank sees and only sees ghost cells (ilocalis trivial, soilocalbecomesNULL) . It turned out that we need to handle the latter case if submeshes are involved the submesh PR.