Hi Marco, currently MoI is not focused on doing sub-d modeling inside of it. It is something that I want to work on in the future.

MoI v4 does support importing a sub-d object and converting it to a NURBS model to use for further modeling operations. That's done in v4 under SubD > Create > "From file".

It is intended that you would do the actual sub-d modeling in a separate polygon modeling app (like Silo, Modo, Blender, etc...) and not directly inside MoI.

- Michael