Screenwriter William Goldman once famously declared that the most important fact of life in Hollywood is that “nobody knows anything.” It was his way of describing a reality that continues to haunt the movie business: Studio executives have no idea which pictures will make money.

Unless, of course, those pictures are made by Pixar Animation Studios. Since 1995, when the first Toy Story was released, Pixar has made nine films, and every one has been a smashing success.

Pixar’s secret? Its unusual creative process. Most of the time, a studio assembles a cast of freelance professionals to work on a single project and cuts them loose when the picture is done. At Pixar, a staff of writers, directors, animators, and technicians move from project to project. As a result, the studio has built a team of moviemakers who know and trust one another in ways unimaginable on most sets.

Which explains how they can handle the constant critiques that are at the heart of Pixar’s relentless process. Animation days at the studio all begin the same way: The animators and director gather in a small screening room filled with comfy couches. They eat Cap’n Crunch and drink coffee. Then the team begins analyzing the few seconds of film animated the day before, as they ruthlessly “shred” each frame. Even the most junior staffers are encouraged to join in...