Unkrich told Digital Spy that he used classic prison break pictures such as The Great Escape and Cool Hand Luke as reference points for scenes where the toy characters are attempting to break out of a daycare centre.
"The only films we referenced really were prison movies. We spent a lot of time watching prison break movies, because we knew that a big part of the film was going to be a prison break," he said.
"We watched The Shawshank Redemption, The Great Escape and Cool Hand Luke. Cool Hand Luke actually ended up being a big influence on the film, there are some very overt references to that movie."
> Click here to watch our full interview with Lee Unkrich