Tony DeRose talk from Pixar

Today is the talk from Tony De Rose from Pixar at the Computer Science colloquium at the University of Toronto. He is talking about Math in the Movies, and started with a teaser trailer of Cars, which will come out on June 9, 2006. There's lots of people in the room as almost everyone has watched a movie made by Pixar like Monsters Inc, A Bug's Life, and Finding Nemo. It's interesting in that when Tony graduated from his PhD, he had a tough decision to decide to become a professor at University of Washington or at University of Toronto. So, he became a professor at University of Washington before going to work at Pixar.

Here is his abstract and bio:

abstract --
Film making is undergoing a digital revolution brought on by
advances in areas such as computer graphics and computational
physics. This talk will provide a behind the scenes look at how
fully digital films, such as Pixar's "Finding Nemo" and "The
Incredibles", are made, with particular emphasis on the role that
mathematics plays in the revolution.

bio --
Tony DeRose is currently a Senior Scientist and lead of the
Research Group at Pixar Animation Studios. He received a Ph.D. in
Computer Science from the University of California, Berkeley in
1985. From 1985 to 1995 Dr. DeRose was a Professor of Computer
Science and Engineering at the University of Washington. In 1998, he
was a major contributor to the Oscar winning short film "Geri's
game", and in 1999 he received the ACM SIGGRAPH Computer Graphics
Achievement Award.

In his talk, Tony talked about how the animation is done in the movies. In a progression reel of the movie, first there is a story reel of frames which are drawn out on paper. Then each frame on paper is then animated with layout, then simulation and adding actors and audio. There's also lighting that needs to be added to the frame, and there is a mathematical formula that calculates the amount of lighting L(x, y) which involves an integral of L(y,z) and shading R(x,y,z). The problem is solving for L(x,y) which is usually done with an approximation.

I've always been fascinated about the making of animation movies and the technical process involved. Tony mentioned about subdivision surfaces where you take the points of a surface, split and average in a subdivision matrix and then as you interate through the subdivision, you can have a smoother surface. He showed how subdivision surfaces was applied to Woody's hand and face from Toy Story 1.

Wow, a lot of the math relates back to signal analysis that I studied in a course about more than 7 years ago. Tony is talking about wavelet noise construction and Perlin noise. Fourier transform, sampling, deja vu for me. I remember I used to have to manually compute the Fourier transform!