LOS ANGELES The kooky caveman characters that come to life in Early Man have been kicking around in Nick Park’s imagination for decades.

Long before he created Wallace and Gromit, Park was taken with Ray Harryhausen’s animated dinosaurs in the 1966 Raquel Welch movie One Million Years B.C.

“I just couldn’t believe real dinosaurs moving around with people,” Park said, recalling the film he saw as an 11-year-old that would inspire his love of animation.

Early Man translates Park’s vision into an epic claymation adventure about a tribe of colourful cave people who stake the future of their homeland on a soccer showdown, despite not knowing how to play.

An ambitious young caveman, Dug, and his loyal pet warthog, Hognob, believe the plucky tribe can prevail.

“I’ve never seen a prehistoric underdog sports movie before,” Park mused.

U.K.-based Aardman Studios tapped its largest production team yet — with nearly 40 animators and sets working at once — to make Early Man, which uses stopmotion animation techniques essentially unchanged since Harryhausen’s day.

It’s a slow and painstaking process to bring clay characters to life.

“We’ve used some of the most advanced filmmaking techniques in post-production, together with stop-motion, which is as old as cinema itself,” said animation director Merlin Crossingham.

Stop-motion animation (or “stop-frame,” as Park calls it) creates the illusion of movement through a series of still images. For Early Man, Aardman’s team of artists built a cast of puppets based on Park’s sketches that serve as the film’s actors. Each seven-inch-tall silicone puppet has a jointed metal skeleton inside so it can move.

“They’re like expensive action figures,” Crossingham said.

The faces are made of modelling clay — except for the noses and eyes, which are hard plastic and serve as “grab points” for animators while changing the puppet’s expression.

Mouldable brows and more than two dozen removable and interchangeable mouths allow for a variety of looks.

Animators pose the puppets for each frame — every movement, every gesture — with 24 frames in each second of film. Mouth movements are synced to pre-recorded vocal performances. (Eddie Redmayne, Tom Hiddleston and Maisie Williams lend their talents here.) For every shot, the puppets are bolted into place on exquisitely detailed sets that stand about two feet high.

“Getting about five seconds of finished film is a really good week,” said animation director Will Becher.

Because the process is so timeconsuming, artists make duplicates of every set and puppet so multiple animators can work on various shots simultaneously.

Park also personally worked with the vocal performers, something he wasn’t always comfortable doing.

“I used to find it quite nerveracking working with actors, especially if they were quite famous actors,” he said.

“I find it much easier to manipulate a puppet or a clay character, because they do as they’re told. And if they don’t, you can squish their head in or whatever you want. With actors, you have to be a little bit more tactful.”