Choose Create, Spline, Automatic Spline.
Spline Automatic ribbon bar
|Use this ribbon bar to automatically create a spline from a string of points that lie in a defined pattern. Select three existing points in the graphics window to define the spline.
The spline passes through the first two points that you select then through all other points that lie within the pattern until it reaches the third selected point.
Choose the Edit End Condition button before creating a spline to further define the spline by setting the tangency of its endpoints in the Spline End Conditions ribbon bar.
C – Edit end conditions
O – OK (fixes live entity and exits function)