Hi Ferrozzo, It's not really feasible to do G2 constructions manually. It's just too difficult to place each control point in the proper location by hand.

Currently you can get G2 continuity in MoI by using either the Fillet or Blend tools.

To use Fillet you make surfaces that initially have a sharp G0 continuity where they meet, and then put in a fillet which then has an option for G2 continuity for the fillet surface.

For Blend you leave some space in between the 2 surfaces and then use Blend to create a smooth in between piece, it also has an option for G2 continuity in it as well.

See here for some more information:

http://moi3d.com/2.0/docs/moi_command_reference7.htm#fillet
http://moi3d.com/2.0/docs/moi_command_reference7.htm#blend

In the future I do want to add more continuity tools, including one for editing an untrimmed surface to make it adapt with continuity to some other one. But that kind of detailed surfacing stuff is a pretty advanced modeling technique - it has been a priority for MoI to focus on simple modeling tools and simple techniques first.

- Michael