separate CAD definition and meshing

[simbilod]

this would be useful if we wanted to generate multiple different meshes from the same resulting CAD, since sometimes the booleans take a while

[HelgeGehring]

Sounds great! Would it be possible to export that intermediate step? I.e. that we would have a two-level cache in the end?

[simbilod]

Yes, we would have to find a way to serialize the gmsh model itself

[simbilod]

The XAO format in 4.13.0 version should allow this https://gitlab.onelab.info/gmsh/gmsh/-/issues/2218

[simbilod]

first attempt in #83 ; ideally we would have separate methods for model.cad() and model.mesh(), but currently both CAD and mesh are tied through the entity_list entities. We need to think of a way to separate them (which defeats the simple interface) or higher-level serialization beyond the .xao file.