Persistent intermediate objects

[alberto743]

It would be useful to have persistent/serializable output objects storing the CSG representation, in order to trigger the output data format drivers (e.g. MCNP, OpenMC, etc.) thereafter.

[shimwell]

partly addressed in PR #144 which splits the start method into two parts allowing

[alberto743]

I guess that this kind of modification may require some substantial redesign of the objects, so that each of them will expose some introspection and explicit serialization drivers.
Probably we may keep this issue as reference as a part of the refactoring.

[shimwell]

There are now some class attributes that get generated during the start() method that can be accessed if that helps

import geouned
geo = geouned.CadToCsg(stepFile='example.stp')
geo.start()
print(geo.UniverseBox)
print(geo.MetaList)
print(geo.Surfaces)