French painter, sculptor, and installation artist, born in Cholet. He was self-taught as an artist and his early paintings were realist still-life subjects. In his first solo exhibition in Paris in 1950 he showed *primitivist paintings and sculpture, reminiscent of, but far more restrained than, the contemporary work of the *Cobra group. In the same year he encountered for the first time the *Concrete art of Max *Bill. Subsequently his work has usually been based on mathematics. In 1960 he was a co-founder of the *Groupe de Recherche d'Art Visuel, but as well as optics and movement he was interested in using systems which combine logic and chance. Sphère-Trame (1962), made from intersecting steel rods and produced as a *multiple, is an object which can appear from different angles transparent and simple or opaque and complex.