Colours?

[RemDelaporteMathurin]

Hi!

I started using this package a bit more and wondered how we could add colours for better visualisation.

[shimwell]

I've been using a mixture of packages to get that effect with CSG geometry.

Here is a minimal example of colors with a CSG geometry outline
https://github.com/fusion-energy/openmc_geometry_plot/blob/main/examples/color_spheres.py

However to get this working with DAGMC geometry we would need to take a different approach to obtaining the get_slice_of_material_ids as dagmc geometry does not support the find method I use (see issue openmc-dev/openmc#2322)

I wanted to redo the get_slice_of_material_ids function anyway so perhaps this is a good opportunity

I think the approach taken in the geometry plotting tab of openmc_plot would work.

So perhaps we refactor openmc_geometry_plot to have another method of obtaining a slice of material ids, that new method could look a lot like the openmc_plot method. Then openmc_plot can finally make use of openmc_geometry_plot and be the gui wrapper package I wanted it to be from the start