David Ryu, Paul Kanyuk
Abstract:
One of the major technical challenges in the animated film
Ratatouille was creating a believable rat colony. In numbers as high
as a thousand, these rats participated in highly complex and
coordinated behaviors ranging from chaotic swarming to gourmet
cooking. Often, the colony was the featured foreground element in
the shot and thus subject to the strict motion standards of our hand-
animated characters. We needed a crowds animation pipeline that had
the flexibility to tackle a wide variety of complex behaviors, while
also delivering motion that could pass muster alongside hero
animation. We chose Massive Software's Massive Prime as our
simulation engine. To ensure animation quality, our Massive pipeline
preserved all the nuances of the input animation and allowed the
animators to easily change the simulations, while still enabling TDs
to use proceduralism to create complex behaviors. To this end we
deployed a number of techniques including a system for baking our
deformer based character rigs into point weights for Massive, motion
retargeting tools for animation cycles, and procedural methods for
swarming, leaping, carrying, and climbing, among others.
Paper (PDF)
Available as Pixar Technical Memo #07-02