 He withdrew from social life, and being unable to join the army immediately because of his injured hand, he went to work in a factory making military uniforms.He went on to serve with various auxiliary units of the armed forces and towards the end of the war in 1917-1918 he was by chance transferred to the Section Cinématographique de l'Armée, where he received his first technical training in film-making.His intellectual conversion to the medium of film had only recently occurred, firstly through a friendship with the actress Musidora (he recalled that she took him to Cecil B. DeMille's "The Cheat" (1915) which awakened him to the artistic possibilities of silent films) and subsequently through encounters with the critics Louis Delluc and Émile Vuillermoz who were developing their own theories of the new art form.