Updating mesh at every timestep (Nek5000 parallel reader)

Hi everyone,

The native parallel Nek5000 file reader of Paraview 5.13.2 works well when the mesh is static. It seems by default, it reads the mesh from the first timestep and never updates it again. However, when we have a dynamic mesh (rotation, refinement, etc), only the first timestep is shown correctly and from the second timestep onward, the fields look strange as the mesh information is no longer valid. Is there an option, to force re-reading the mesh at every new timestep for Nek5000 reader?

Thanks in advance

Hi @Emo

Please share your data.

Best,

@mwestphal at Unfortunately, each timestep is about 22GB, but I can share any other information you need.

TBH your description sounds like a bug, I doubt there is a workaround apart using another file format.

Reproducing the issue with a smaller, shareable, dataset would go a long way.

@mwestphal sure, I’ll try to create a smaller version of this to share. I think if there was an option to read the mesh per timestep, everything else should be fine.

Nek5000_dynamicMesh.tar.gz (3.5 MB)
@mwestphal I have attached a small 2D case. The mesh is refined from timestep 1 to 2, the first timestep is shown correctly as the mesh is loaded from the first timestep. The second timestep looks strange as the mesh is cached from the first timestep which is no longer valid

I confirm there is a bug, please open an issue here:
https://gitlab.kitware.com/paraview/paraview/-/issues

Sadly, there does not seems to be any workaround without modifying the source code afaict. A proper fix is needed.

Sure, I opened an issue on Gitlab: https://gitlab.kitware.com/paraview/paraview/-/issues/22890

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