New segments, of any type, can be easily added to a curve selected for modification. These new segments must always be added at the end of the selected
To add a new segment, click on the Add button within the Segments frame. Prior to picking or specifying the control points for the new
segment, select the type of segment from the Segment Type frame. If there are no database surfaces present, only non-database constrained segment
types will be available. Otherwise, all segment types should be available except for the Pole type. Once the type of segment to be added has been
selected, specify in the Point Placement frame or pick in the Display window the control point locations for the new segment.