Hi Petr,

>>The control point structure look similar for both fillet and blend in MoI; but if you would copy the curves to Rhino and turn control points on, you could see the difference.

Are you not looking at a default fillet from MoI (Circular) compared to a default blend(G1).

Fillets in MoI can also be made to G1/G2/G3 so a need to compare similar settings (with fillet/blend) on such a planer construction.