You can select
the following entities for both sides:
A point in the work area.
A plane point.
A curve point.
A position in the inner of a surface.
A position on a surface edge.
The blend curve is created between the pick positions, and it is connected to the
adjacent entities with G0, G1, G2, or G3 continuity.
Recommendation:
Choose a sufficiently large order so that the feature can be usefully created with the
defined options. Especially, the manipulation of the G1/G2/G3 Shape factors by a control
point modification does not work if the order is too low.
The maximum order for creating a blend curve with G3-G3 continuity is 8. The curve is
always created with the required order if you don't reduce the maximum order.