The Spline command fits a cubic spline through the control points of a database polyline or fits a bicubic spline surface through the control points
of a bi-linear database surface. The original curve or surface is replaced by the new cubic spline or bicubic surface. This command is implemented immediately
without a command panel appearing.
A database line before (top) and after (bottom) applying the Spline command.
Tip: The Spline command can be useful for replacing piecewise database curves and surfaces imported from
a Segment file or PLOT3D file into continuous
curves and surfaces.