“Just because you haven’t seen something, doesn’t mean it’s not there,” Mary Katherine’s father tells her in Epic, Blue Sky Studios’ upcoming 3D computer-animated fantasy. His words prove prophetic when Mary Katherine is thrust into a grand adventure within a hidden forest world, a world that had been right under her nose.

The task of bringing that secret world to life fell to a team led by Chris Wedge, director of Robots and the Oscar-nominated Ice Age.

"For me, when I start thinking about a new project, it always starts with a world," he told a group of reporters gathered recently at 20th Century Fox Studios in Los Angeles. In Epic, that world is the forest introduced by author William Joyce in his 1996 children’s book The Leaf Men and the Brave Good Bugs. "We take you to the forest and try to get you to experience it in a way you haven't thought of before."

Epic’s forest is expressed from a miniature perspective, where slugs, snails, frogs and others woodland creatures live and work together within a hidden society. It’s a world that, until now, has gone unnoticed by most people. “Mainly because we don’t look hard enough,” Wedge said.

It’s there a battle is being waged between the forces of life and the forces of decay, between the Leaf Men and the Boggans.

The Leaf Men are the protectors of the woods. "They are the little samurai of the forest and by virtue of their scale and the physics of that scale they can move like super heroes,” the director explained. “They can jump like grasshoppers. If they were us, they could jump thirty-feet or carry six of their friends on their backs. They ride hummingbirds through the forest like jetfighter pilots!”

Living by the credo "you can't stop the rot," and fighting on the side of decay, are the Boggans. “The Boggans are like the little creepy crawlers you find under a rotten log,” he said. “The Boggans are kind of dimwitted but deadly, and they come at you with massive numbers. They’re led by Mandrake, who "is not dimwitted at all.”

“He's a very intelligent, dry, ironic wit and he is going to go after our guys," Wedge said. "He's played by Christoph Waltz (Django Unchained). No casting against type here. That’s' the voice I wanted for this.”

Outnumbered, but not outmatched, are the Leaf Men heroes Ronin and Nod. Voiced by Colin Farrell (In Bruges), Ronin is the leader of the Leaf Men. “He's the stoic, career General that embodies the Leaf Men slogan, 'many leaves, one tree,'” the director said. “We're all individuals, but we're connected.” Nod, played by Josh Hutcherson (The Hunger Games), on the other hand, is a younger recruit who doesn’t necessarily embrace that creed. "He is a bit more of an individual. He's a young guy. He's got plenty of mistakes ahead of him. He's good-natured and we love him, but he has got to do all the dumb things that teenagers do."

Ronin and Nod serve together under Queen Tara, played by Beyoncé Knowles (Dreamgirls). "She is the queen of the Leaf Men and the life of the forest, literally," Wedge said. "There is magic in the movie and this is where it manifests, with Tara. Without Tara the forest can't survive. Things grow around her. Flowers follow her like they're following the sun."

Mub and Grub, a slug and snail, receptively, are the comic caretakers of a pod patch where Queen Tara will be performing a special ceremony that’s crashed by Mandrake and his Boggan army.

"They are fairly low-level on the evolutionary scale, but that doesn't stop them from having aspirations as high as any one of us," Wedge said of the duo. "Grub, who is played by Chris O'Dowd (The IT Crowd) expects that some day he will be a Leaf Man. Grub, who is played by Aziz Ansari (Parks and Recreation), is a bit of a player, is a bit of a ladies man."

"There are some humans in the movie," Wedge added. Professor Bomba, voiced by Jason Sudeikis (Saturday Night Live), is the absent-minded professor and the one person in the world who believes that the forest creatures might be out there. "He's made such an obsession of it that he's pushed everything else in his life away, including his wife and daughter."

Early in the film, Professor Bomba is visited by his teenage daughter, played by Amanda Seyfried (Les Misérables). "She was raised thinking he was a nutcase, so she comes to see if there is anything there, if he's as crazy as she's been told," Wedge said. Her questions are soon answered when she is magically transported into the world of the Leaf Men.

Once united, the heroes must work together to defeat Mandrake and his Boggan army. "Our main characters are going to have to embrace those things that create heroic characters, to learn to be one of the leaves of many," Wedge said.

The presentation included character sketches, production designs and several clips, offering a small taste of a rousing Danny Elfman score.

Wedge said Epic is both a departure and an evolution for Blue Sky Studios. "If you know our movies, our Ice Age movies, Horton Hears a Who! and Rio, we typically start with fun kind of comedy and characters," he said. "This film starts there, but it moves into other realms, into more of a complete action-adventure thing. I wanted to make a movie that felt more like a live-action, action-adventure movie."

Epic opens May 24.