Menu: Draw / Lines / Curve
Shortcut Key: C
Draws a cubic spline curve through three or more points. The points for a curve do not have to lie in the same plane.
The curve can be saved as a line by checking Save as a Line.
TIP: To make a sharp break or “corner” in the curve, set two consecutive points in the same location. This will cause two separate curves to be drawn, one on each side of the corner.