 Translating the film into 3 @-@ D involved revisiting the original computer data and virtually placing a second camera into each scene , creating left @-@ eye and right @-@ eye views needed to achieve the perception of depth . Unique to computer animation , Lasseter referred to this process as " digital archaeology . " The process took four months , as well as an additional six months for the two films to add the 3 @-@ D. The lead stereographer Bob Whitehill oversaw this process and sought to achieve an effect that affected the emotional storytelling of the film : 
