The actor inside Raphael's Turtle suit is striking his own high kick, but he owes his smile to state-of-the-art ''puppetechtronics.''
The performers within the 15-piece, foam-and-latex costumes from Jim Henson's Creature Shop can walk, dance, and even somersault on their own recognizance. They are, after all, martial artists. But their facial expressions are worked by off-camera puppeteers.
Using a ''super Waldo'' a computer system named after a character in one of sci-fi novelist Robert Heinlein's books each puppeteer operates one Turtle. (For comparison purposes, consider that at any given time more than 50 engineers may have operated the hungry plant in Little Shop of Horrors.) All told, there are 24 super Waldo functions operating 30 motorized cables in each Turtle's head, giving the Turtles a nearly human range of expressions: The Turtles smile, smirk, dimple, take pleasure in pizza. ''It's amazing there was still enough room in there for an actor's head,'' a crew member says. Actually, the 40 pounds of motors, receivers, amplifiers, and on-board computer are housed in backpacks in the Turtles' shells.
For each Turtle, a joystick works the eyes, a glovelike apparatus works the jaws, and headsets fitted with infrared light sensors work the lips, synchronizing them with the giant mouths so that they look as if they are actually saying the voiced-over dialogue. The sensors essentially can read the puppeteer's expression and then relay it by radio to the Turtle mask, which then mimics it.
Before shooting, the actors and puppeteers meticulously rehearsed each scene together to coordinate their work. ''If they deviated,'' explains another crew member, ''the body and the mouth were out of sync.''