The dataset attributes are written lowercase, which seems wrong. The output results in <CellData scalars="test">, while <CellData Scalars="test"> would be correct. For definition of the VTK names see here: https://gitlab.kitware.com/vtk/vtk/-/blob/v9.0.1/Common/DataModel/vtkDataSetAttributes.cxx#L42
I do not know how VTK and ParaView (should) handle this internally. I found a few code points where it looks like they at least sometimes do a case insensitive check, but ParaView only works fully as expected when using the uppercase first letter Scalars. Also files exported by ParaView use the uppercase first letter.
Bug probably is here: https://github.com/pyscience-projects/pyevtk/blob/v1.2.0/pyevtk/vtk.py#L389-L398
The second bug is in the high-level interface: https://github.com/pyscience-projects/pyevtk/blob/v1.2.0/pyevtk/hl.py#L48-L57
There, always the first key is set as scalar array, no matter if the data behind this key is scalar or vector data. Also the Vectors attribute is never set at all, even if there is vector data.
I noticed two bugs with the dataset attributes:
<CellData scalars="test">, while<CellData Scalars="test">would be correct. For definition of the VTK names see here: https://gitlab.kitware.com/vtk/vtk/-/blob/v9.0.1/Common/DataModel/vtkDataSetAttributes.cxx#L42 I do not know how VTK and ParaView (should) handle this internally. I found a few code points where it looks like they at least sometimes do a case insensitive check, but ParaView only works fully as expected when using the uppercase first letterScalars. Also files exported by ParaView use the uppercase first letter. Bug probably is here: https://github.com/pyscience-projects/pyevtk/blob/v1.2.0/pyevtk/vtk.py#L389-L398Vectorsattribute is never set at all, even if there is vector data.