Does VTKHDF Format Support Dynamic Meshes with Changing Topology Over Time?

[lgivord (Lucas Givord (Kitware))]

@amnp95

mesh geometry (e.g., the number of cells, points, connectivity, and offsets) changes at each time step, and I need to represent these changes accurately in the VTKHDF format.

I understand that VTKHDF provides support for temporal data through the Steps group, which tracks time step-specific offsets for Points, Connectivity, Offsets, and Types. However, I am unsure if the format

Hello @amnp95,

However, I am unsure if the format explicitly supports scenarios where the mesh topology itself changes over time (e.g., adding/removing cells or updating connectivity).

It definitively makes sense to support such scenario.

Few month ago, I wrote an issue regarding “varying cells” (which is exactly what you call ‘dynamic meshes’) : https://gitlab.kitware.com/vtk/vtk/-/issues/19257

As you can see, we discuss a lot with another contributor, the current status is here: https://gitlab.kitware.com/vtk/vtk/-/issues/19257#note_1548628. In short, I think that the current spec is enough to support it and the error is in the vtkHDFReader because we don’t read correctly the NumberOfCells dataset, however we may need to investigate it more to confirm that.

Currently, I don’t have funding to continue to investigate it or to fix it. If you have any insight do not hesitate to share it (and if you want to contribute, you’re welcome )