ORLANDO, Fla. -- If you want to make a film about a not-so-modern "Stone Age Family," it helps to start out with a wish list.
"If I was going to see a caveman film, what would I want to see?" asks Kirk Di Micco, co-director of "The Croods."
"We've never seen computer-generated cavemen," says Chris Sanders, the other co-director. "You've seen ‘Quest for Fire.' You've seen ‘The Flintstones.' But this is entirely different. We wanted to do for cavemen what ‘28 Days Later' did for zombies.
"Our cavemen are very gifted, physically. They can run 40-60 miles per hour, throw rocks huge distances, and hit their targets. But mentally, they have beginner's minds."
"Tar is way up that list," says his co-director, Kirk DiMicco. "But nobody had ever animated it. We had to manage a tar pit, and the animation that we used was a simulating of flowing cloth. You see tar, but the movement was mimicking cloth." They wanted their Stone Age to have a volcano.
"We have a pyroclastic flow in the film that I've never seen the likes of before," Sanders ("How to Train Your Dragon" and "Lilo & Stitch") says.
"A titanic volcanic collapse that is the final curtain on this world as they knew it. Do I think we outdid Walt (Disney, director of an epic eruption in "Fantasia")? I wouldn't be so bold as to say that. You be the judge."
Di Micco ("Space Chimps") adds that "there are no man-made things in the movie," which opens todayin Pittsfield, Lanesborough and North Adams. "It's all nature, all exteriors, and that's a HUGE undertaking. Just caves and cavemen and forests."
They based the human characters, voiced by Oscar winners Nicolas Cage and Cloris Leachman, as well as Emma Stone and Ryan Reynolds, on assorted members of the animal kingdom. It's a trick Sanders learned from his animators on "Lilo & Stitch," where the hyperactive alien had the movements of a Florida gecko.
Of Eep, the Stone-voiced cave-teenager, Sanders says, "Her movements are based on a cat's.
"Grug (her dad, voiced by Cage) has movements based on a gorilla. Gran's (Leach man) movements are based on a crocodile, the way they walk. Fanny, the youngest, has movements based on a terrier."
Yeah, they knew their Dream Works movie would be compared to Fox's lucrative "Ice Age" series. The Holly wood Reporter says " ‘The Croods' is too uneven to help it approach that series' mammoth market share. But its mostly fast-moving roller coaster of kinetic action and its menagerie of fantastic creatures -- from cute to menacing -- should keep kids entertained."
And, as the Hollywood Reporter's David Rooney notes, kids will have "no trouble grasping the simple message to face your fears and embrace change." That's what the filmmakers were aiming for, "that take away every modern reference, from society to police, and human nature is still basically the same," Sanders says.
Some, especially the young, embrace change. And some, like the parents and grandparents, resist it.
"It's a great metaphor, having a guy confronting change when his world is literally changing under his feet," says De Micco.
That, he adds, went on their "What do we want in our caveman movie?" list.
"And it went at the very top."