Inside a cavernous office-park building in this southwest English city, dozens of grown-ups are moving goofy clay figures around like kids playing with their Barbies or GI Joes.

A hundred miles away at a similar space in East London, more adults are doing the same with lanky, big-eyed puppets that speak in the voices of Johnny Depp and Helena Bonham Carter.

It's not a mass epidemic of people relapsing to childhood. These are the movie sets for Hollywood's latest animated extravaganzas, "Wallace & Gromit: The Curse of the Were-Rabbit," (search) a big-screen version of the TV cartoons starring a cheese-obsessed Brit and his faithful dog, and "Tim Burton's Corpse Bride," (search) about a jittery bridegroom yanked into the underworld to wed a decomposing babe.

Amid an onslaught of computer-generated films such as "Shrek" and "The Incredibles" that has virtually suffocated hand-drawn cartoon features, the makers of "Wallace & Gromit" and "Corpse Bride" have reverted to one of the oldest forms of movie animation: Meticulously moving inanimate objects around and photographing them, frame by frame.

"It's great. I get to play with all these toys. Really expensive toys," said animator Teresa Drilling during a break from work on a "Wallace & Gromit" action sequence, in which lovable pooch Gromit and a rival canine engage in a dogfight in small airplanes.

Given the time involved — it can take a week to shoot a sequence lasting just five or six seconds — the form known as stop-motion animation has been a rare breed. Just three notable feature-length films have been made in stop-motion in the past 12 years: 1993's "The Nightmare Before Christmas," produced by "Corpse Bride" co-director Burton, 1996's "James and the Giant Peach," and 2000's "Chicken Run," from "Wallace & Gromit" creator Nick Park.

Production wrapped early this summer on "Wallace & Gromit" and "Corpse Bride," and both movies premiere at the Toronto International Film Festival, which begins Thursday. "Corpse Bride" opens in limited release on Friday and expands nationwide Sept. 23. "Wallace & Gromit" follows on Oct. 7.

"How often do you get a stop-motion feature film? Every five or 10 years? Now you get two of them, and both starring Helena Bonham Carter," said Mike Johnson, Burton's directing partner on "Corpse Bride."

Along with providing the voice of the dead chick pursuing Depp's character in "Corpse Bride," Bonham Carter does the vocals for the female lead in "Wallace & Gromit," a high society dame who captures Wallace's heart.

It's a coincidence that two stop-motion features are coming at the same time, though the filmmakers hope the movies succeed well enough to encourage more use of the process.

"There's just something visceral about moving a puppet frame by frame," Burton said. "There's a magical quality about it. Maybe you can get smoother animation with computers, but there's a dimension and emotional quality to this kind of animation that fits these characters and this story."

"Corpse Bride" was created using slender puppets made of rubber, with metal skeletons so intricate the filmmakers hired jewelers to help craft the tiny gears and joints. Miniature cranks in the puppets' ears control their facial movements, enabling animators to create remarkably lifelike smiles, frowns and other expressions.

The "Wallace & Gromit" characters were sculpted of clay, with metal skeletons beneath. Animators had a variety of mouths they would swap on to the characters to mimic speech, each simulating the shape of the lips for different phonetic sounds.

"Wallace & Gromit" comes from Aardman Animations, which introduced the characters in three TV shorts from 1989 to '95 and also made "Chicken Run." In their big-screen adventure, Wallace and Gromit run a pest-control outfit and encounter a monstrous mutant rabbit whose appetite threatens to ruin the town's annual giant-vegetable contest.

Jeffrey Katzenberg — co-founder of DreamWorks, which is releasing "Wallace & Gromit" — notes that glossy, cutting-edge computer animation is a nice fit for the hip, sarcastic tone of the studio's "Shrek" films.

Likewise, lower-tech clay animation fits the droll British humor pervading "Wallace & Gromit" and other Aardman films.

"The humor is slightly chunky and slightly naive," said Steve Box, Park's co-director on "Wallace & Gromit." "There's a kind of innocence, a handmade quality to it, and it's really reflected in the puppets.

"It's like an ongoing joke we the filmmakers share with the audience, which isn't dissimilar to Jim Henson and the Muppets. You know they're puppets. They are made from clay, and yet you allow yourself to enter into this drama, like a live film full of tension, and you treat them seriously all the time, though you know they're made of clay. I think that lets people really have fun with it."

Stop-motion animation dates back at least to 1907, when J. Stuart Blackton used the technique to show a dinner being prepared by invisible hands in his short film "The Haunted Hotel."

The technique has a venerable history in live-action films, used to create dinosaurs in the silent classic "The Lost World," the giant ape in the original "King Kong," the beasts in films by special-effects master Ray Harryhausen and the giant robots in "RoboCop."

Stop-motion has had a varied life on television with such shows as "Gumby," "Davey and Goliath," Rankin-Bass productions like "Rudolph the Red-Nosed Reindeer" and the California Raisins commercials.

Aardman gave stop-motion a modern makeover in the mid-1980s with its ultra-cool animation for Peter Gabriel's music video "Sledgehammer."

Advances in realistic computer effects in the last decade have largely choked off stop-motion animation in live-action films. And despite the timing of "Corpse Bride" and "Wallace & Gromit" along with Aardman's "Creature Comforts" TV series, stop-motion's future looks spotty.

"I think we're either going to die on the vine, become a buggy-whip factory, or we're going to be discovered as a folk-art craft," said "Corpse Bride" cinematographer Pete Kozachik, who worked on "The Nightmare Before Christmas" and "James and the Giant Peach."

While Aardman is using computer animation for its next film, "Flushed Away," the company has other clay-animated films on the drawing board, ensuring that the form likely will have periodic revivals on the big screen.

"When computer animation came in, they thought it would be the death of 3-D stop-motion, but it has a particular life of its own," said Dan McLaughlin, who teaches animation at the University of California at Los Angeles. "It's hand-crafted and has a spontaneity. It can feel more alive. The hand of the individual is right there. Sometimes, you even see the thumbprints in the clay."

As they wound down on production of "Corpse Bride" and "Wallace & Gromit" this summer, neither team of filmmakers was devoting much thought to the future of stop-motion animation.

They had enough to do just getting their playthings to do what they wanted.

"At the end of the day, we get paid to play with toys," "Corpse Bride" co-director Johnson said. "So how bad can it be?"