what types surfaces are used ?

Hello,

When I make a wire with several edges that can be curves, I can also build a face with a closed wire. My question is what type of surfaces are computed in this case ? Bezier, Bspline, others ? (If the check button that forced planar faces is False)

Then the shape of this last surface is oriented. So I tried to inverse the order of edges in the wire to change the orientation, the result shape is the same. How can I control this surface ?

Best regards,

Thomas.