Hi Elang,

re:
> This is really cool! What condition for a model in MoI that is 3D printable? Do all parts need to be solid?

Usually yes they will be expecting that the model is a solid.


> Do they need to be union-ed into one solid model?

It depends on the slicing software. some may be able to tolerate several solids as long as they don't have overlapping surface areas.

But I would recommend forming them into one solid.

- Michael