PG-13

If a band has a hit CD that tops the charts and spreads like wildfire around the globe, then takes 12 years to make another album, that usually means trouble. They may not know how to match their success… or they might have forgotten what made them great in the intervening decade. The same is true of other artists, too, like famous authors or movie directors—a long hiatus is rarely a good sign, for the fans or the artists. But then there are those few who are such adepts of their art, such guru-on-the-mountain masters in their fields that they simply choose only the projects that interest them, and make them only when they are darn good and ready, unleashing their masterpieces on the world at the pace that they choose. They’re not afflicted by writers’ block, they’re afflicted by genius.

Twelve years after the colossal crossover mega-hit “Titanic,” director James Cameron has returned to blockbuster moviemaking with “Avatar,” a gorgeous 3D sci-fantasy super-adventure set in the future on the distant world of Pandora. Humans have found their way to the jungle planet, but can’t breathe the air or face the tough natives without armored suits and lots of guns.

The Avatar program is the alternative, allowing a small number of humans to temporarily move their consciousnesses into vat-grown bodies identical to those of the native humanoid (and 10 feet tall and blue) Na’vi.

It’s into this program that Marine Jake Sully (Sam Worthington) accidentally falls, soon to find himself caught between the integrated-with-the-planet culture of the Na’vi and the strip-mine-first-and-ask-questions-later human incursion.

The story is thin, but the adventure is huge and has a killer depth of field. Conceived from the beginning as a modern mainstream 3D hit, the six-legged tigers, alien rhinos, giant tree city and dragon/helicopter dogfights all get a little extra punch from happening not just on the screen in front of you, but in the air above you.  If you’re still stuck in the red/blue glasses era and aren’t familiar with the current generation of polarized-light 3D, then “Avatar” will be a delightful shock—rich and deep, smooth and fluid, it’s easy to see why so many filmmakers are excited about 3D again.

In Cameron’s hands, it’s more than a gimmick, since the vibrancy of the animated creatures and sets stand on their own, 3D or not. He’s also put together a relatively bloodless movie with broad appeal, ensuring it will be enjoyed beyond the geekcore community—some of us might show up for any movie with a spaceship in it, but how many of those would we be comfortable bringing our moms to? Odds are that she’ll enjoy the ride that is “Avatar” as well.

There are a few missteps. Sigourney Weaver seems underutilized, and when she’s in her own avatar, it looks a little like a cruel Photoshop trick. Also, the mineral the humans are looking for on the planet is called “unobtanium,” which is a cringe-worthy moment (were “youcantgetitite” and “wereallsoldoutispar” already trademarked?) that underscores the already-light dialogue. But these moments are more than overcompensated for by all the leaping, bounding adventure. Who doesn’t want to ride a dragon and date a blue girl? Sold!

In the past 25 years, James Cameron has made surprisingly few movies, but that’s part of his gift of continuing to grow and change and somehow always hit the mark, even though they have been very different marks: “Terminator” in 1984, “Aliens” in 1986, “The Abyss” in 1989, “Terminator 2” in 1991, “True Lies” in 1994, and “Titanic” in 1997.

If you’re looking for any of those other films, you’ll be disappointed. “Avatar” is not the gritty sci-fi of “Terminator,” the horror of “Aliens” or the romance of “Titanic,” but it is an exploration of the future of filmmaking, and an adventure of such scope that it reminds us why we keep believing in movies.