Since CGI didn't exist at the time, artists hand-painted a glass matte and carefully positioned the camera to create a breathtaking illusion in this Charlie Chaplin scene. For the iconic roller-skating scene that appears to show Chaplin on the edge of a towering drop, artists hand-painted a cityscape onto a sheet of glass, which was then positioned precisely in front of the camera to create a seamless illusion of height. Credit: Roy Export S.A.S. | History In Pictures