Paul de Casteljau

Paul de Faget de Casteljau, born in 1930, was a French mathematician and physicist. He is known for introducing in 1959 the notion of polar forms and a recursive algorithm for evaluating and representing polynomial curves expressed in the Bernstein basis, an algorithm that now bears his name. This algorithm, discovered while he was working for the automobile manufacturer Citroën on computer-aided design, was kept secret for nearly sixteen years before being made public in 1975. It is one of the foundations of computational geometry and is closely linked to Bézier curves, which are a direct application of it. De Casteljau also contributed to unifying the theory of Bézier curves and that of splines under the broader theory of blossoms, thereby providing a coherent algebraic approach to geometric modelling. His final research concerned quaternions and metric geometry.