Drawing Control Splines
To draw a control spline:
1. Click Control Spline in Geometry.
2. Click Create in Control Spline.
3. Specify a sequence of control points. Note that these points make up a control polygon which "controls" the shape and size of the resulting control spline. The first control point serves as the begin point of the control spline. The last control point serves as the end point of the control spline.
4. Click End.
Creo Elements/Direct Drafting draws a spline curve based on the control points you specified.