Extract Surface does not remove internal surfaces

[I originally posted at https://gitlab.kitware.com/paraview/paraview/-/issues/22185#note_1378880 but I was advised to post here].

I have a file [tried with VTU and Fides] written in parallel [MPI]. When I open it I can see internal surfaces on the borders between the parallel partitions of the mesh. The Extract Surface filter has two options, “Piece Invariant” and “Remove Ghost Interfaces” which from their description more or less sound like they should get rid of the internal surfaces but they actually don’t [nor does any combination of the two].

Is this correct? Am I misunderstanding what these options do?

I tried to use the CleanToGrid and CleanCellsToGrid filters but they didn’t do anything.

I am attaching the file I am using to test this, it’s in Fides BP5 format.
uR.bp.zip (106.7 KB)

Did you try the GhostCellsGenerator before the Extract Surface ?

I tried it just now and unfortunately it didn’t change anything :frowning:

My bad, GhostCellsGenerator is only a thing if you are running a pvserver with MPI.

Can you share the vtu file ? Fides is not enabled by default in ParaView

Sure, here comes!
uR.zip (441.1 KB)