Director and screenwriter Pete Docter is responsible for some of Pixar's most beloved films — he directed Monsters, Inc. and Up and worked on WALL-E and Toy Story among others. Yesterday, he spent several hours fielding questions from Redditors, giving some excellent comments on the writing process, his characters, and what exactly it means to direct an animated film. "Are you standing over some animator's shoulder saying 'Sully looks sad, but he should look morose'?" one commenter asked. Docter responded:

Around here, a director usually comes up with the concept and then shepherds that idea along all the way until its done. He/she may write, draw, animate, or do voice work, but the primary job is to be able to communicate to the 400+ amazingly talented people who do the actual work. I have to clearly state what it is I'm looking for from the animation in this shot, or what the fire effects should look like in this other shot. Because animation is done in pieces, you seldom have the benefit of seeing what the movie (much less an individual shot) will look like until it's all done, so you have to have a good imagination. But more important than all of that — I'd say the majority of my job is creating a story and characters that people care about.

The hectic process of directing, he said, helped inform Up:

[Up] was a combo of doing something with a grouchy old man character (which just seemed fun) and my own feelings of wanting to escape the world. Nobody warned me that as a director basically all I do is run around and talk to people all day, and I'm not an extrovert... so by the end of the day I usually wanted to crawl under my desk. That feeling of getting away from the world led to the story of Up.

The AMA, which was interrupted midway through by a fire alarm in Docter's building, is now finished, but there's plenty of good stuff over on Reddit.