Curves
Curves and surfaces for CAD/CAM

After a few attempts at representation using Fourier series (Fayard) or Cartesian forms (Inaba), such as :

the representation now universally used is that of rational or non-rational polynomial parametric functions, which had been the subject of Isaac Schönberg's work after 1940, but to which industry's attention had hardly been drawn, as there were not then any means of calculation fast enough to justify practical application.