Smooth object form cubic spline

 From:  Frenchy Pilou (PILOU) 2 Jan 2021  (4 of 4) 
10092.4 
A funny method :)
The LineWeb http://moi3d.com/forum/index.php?webtag=MOI&msg=3666.1

Move the Polyline
LineWeb between the 2 polylines
LineWeb again with the jointed lines in Curve Mode
et voilà :)

EDITED: 2 Jan 2021 by PILOU