It might be surprising to find a biologist pushing the frontiers of computer animation. But Torsten Reil is bringing cheaper, lifelike digital characters to video games and films. As a doctoral researcher in neural systems at the University of Oxfrd, Reil programmed computer simulations that mimicked human and animal movement, and in 2001 he cofounded NaturalMotion in Oxford, England, to commercialize that work. To create characters that move realistically, conventional animators draw extensive series of frames that are played back- repetitively- in set sequences. But Reil wrote software that an animator uses to program a nervous system for a character he or she draws just once. The code makes the character’s body obey the laws of physics and react automatically to changing on-screen situations. NaturalMotion’s first product is already saving game developers and visual-effects companies thousands of dollars by accelerating animation, Reil says. Look for his characters in the upcoming Hollywood epic Troy. Reil recently won a grant from the British government to model the gaits of children with cerebral palsy, to help doctors determine the neurological basis of the disorder.