 After rough animation was complete, it was run through the normal process of traditional animation until the cels were shot on the rostrum camera with no background.The animated footage was then sent to ILM for compositing, where technicians animated three lighting layers (shadows, highlights, and tone mattes) separately, to make the cartoon characters look three-dimensional and give the illusion of the characters being affected by the lighting on set.Finally, the lighting effects were optically composited on to the cartoon characters, who were, in turn, composited into the live-action footage.