Demonstrate ParaView-like VTK viewer in notebooks

[nikosavola]

Make an example notebook of simulating something in Elmer and looking at the resulting field with something like https://itkwidgets.readthedocs.io/en/latest/integrations.html#vtk for a fully notebook workflow.

[nikosavola]

There's also pyVista which looks really good

[Dzupdu]

Pyvista seems to work really nicely and with the correct packages installed the images can be rendered interactively such that the can be rotated and zoomed in the notebook

Example code:

# might need to install also trame and trame-vtk packages
import pyvista

ds = pyvista.read('./waveguides_n_guides_1_f10_t0001.pvtu')
ds = ds.threshold(scalars='GeometryIds', value=(1,1))
ds.plot(scalars='electric field re e', cpos='yx', zoom=4.0)