James Cameron's 'Avatar' takes place on a planet called Pandora, where American corporations and their military mercenaries have set up bases to mine a surpassingly precious mineral called unobtanium. The vein of awe mined by the movie is nothing short of unbelievium. This is a new way of coming to your senses -- put those 3-D glasses on your face and you come to a sense of delight that quickly gives way to a sense of astonishment. The planetary high doesn't last. The closer the story comes to a lumbering parable of colonialist aggression in the jungles of an extragalactic Vietnam, the more the enchantment fizzles. Much of the time, though, you're transfixed by the beauty of a spectacle that seems all of a piece. Special effects have been abolished, in effect, since the whole thing is so special.

　　 The word 'avatar' wasn't invented by Mr. Cameron, though everything else in the production seems to have been. (With the help, that is, of a few thousand colleagues around our own planet.) In Hindu myth, an avatar is a deity descended to earth in human form. In computer parlance it's an icon that represents a person in virtual reality or cyberspace. In the movie it's a manufactured body that's remotely controlled -- not by some hand-held clicker but through brain waves generated by a human being who functions as the body's driver.

　　 If this sounds technobabbly in the description, it's dazzling in the execution. The main driver-to-be -- or, rather, animating spirit-to-be -- is an ex-Marine, Jake Sully (Sam Worthington) whose combat injuries have left him confined to a wheelchair. He's part of a scientific program run by a tough cookie named Grace Augustine; she's played by Sigourney Weaver. The program has begun to explore Pandora, whose atmosphere is toxic to earthlings, using avatars with recombinant DNA -- part human, part alien -- constructed along the lines of the planet's dominant species; they're very tall, very blue, Giacometti-slender and Superman-agile. The movie offers several lyrical passages, but one of the best belongs to Jake. It's when he inhabits his avatar for the first time and discovers that his new legs can take his lithe new body through some of the most sublime scenery on not-Earth.

　　 No description of that scenery will spoil the experience of the 3-D process (which dispenses with the usual eye-catching tricks) or the seamless integration of live action, motion-capture, animation, computer-generated images and whatever other techniques went into the mix -- maybe witchcraft or black magic. (I haven't seen the IMAX version; that's for my next viewing.) Some of the flora suggest an anhydrous Great Barrier Reef (airborne jellyfish, coral-colored conical plants that spiral down to almost-nothingness when touched) or, in the case of Pandora's floating mountains, represent an homage to the Japanese animation master Hayao Miyazaki. As for the fauna, they're not only prodigiously varied -- flamboyant dragons, six-legged steeds, elephantine chargers with heads like battering rams, nature-blue in tooth and claw -- but creatures with convincing lives of their own, unlike the cheerfully bizarre creations that filled the Mos Eisley cantina in 'Star Wars.'

　　 Then there are the indigenes, the French term for natives being appropriate because Pandora evokes the Indochina that existed before France's doomed war against an indigenous insurgency, as well as the Vietnam that became a battleground for American troops. They're called the Na'vi, and to describe them as humanoid may be to defame them, inasmuch as they, unlike most of the film's Americans, revere their planet and live in harmony with their surroundings. The most beautiful of the Na'vis -- at least the one with the most obvious star quality -- is a female warrior named Neytiri. As most of our planet already knows from the publicity, Jake falls for her in a big but complicated way.

　　 Big because Neytiri, as played by Zoe Saldana, is so alluring -- cerulean-skinned, lemon-eyed, wasp-waisted, long-tailed, anvil-nosed, wiggly-eared (trust me, it's all seductive) and given to feral snarls in the heat of battle. But complicated because Jake is secretly working both sides of the jungle. He's in love with Neytiri, and soon embraces her people's values. (Yes, there's circumstantial evidence that Mr. Cameron knows about 'Dances With Wolves,' along with 'Tarzan,' 'Green Mansions,' 'Frankenstein,' 'Princess Mononoke,' 'South Pacific,' 'Spartacus' and 'Top Gun.') At the same time, Jake is spying for a gimlet-eyed military commander, Col. Miles Quaritch. (Stephen Lang proves that broad, cartoony acting can also be good acting.) The evil colonel has promised the ex-Marine a procedure that will restore the use of his paralyzed legs in exchange for information that will help chase the Na'vi from their sacred land, which happens to be the only place where unobtainium can be obtained.

　　 It's no reflection on Mr. Worthington or Ms. Saldana, both of whom are impressive -- though how, exactly, do you judge such high-tech hybrid performances? -- that their interspecies love story lacks the heat of Leonardo DiCaprio and Kate Winslet clinging to each other on the storm-swept decks of 'Titanic.' Teenage girls will not return to see this film half a dozen times or more unless they possess a rogue gene for wigglable ears. But then 'Avatar' revises the relationship between everyone in the audience and the characters on screen. Actors have always been avatars; they've always represented our hopes and fears in the virtual reality of motion pictures. In much of this film, however, they've been transformed by technology into a new and ambiguous breed of entertainment icon -- not the quasihuman denizens of 'The Wizard of Oz,' or the overgrown glove puppets of 'The Polar Express,' but nearly palpable fantasy figures that inhabit a world just beyond our reach.

　　
The fantasy quotient of 'Avatar' takes its first major hit when the Na'vi take their first hit from the American military. Mr. Cameron has devoted a significant chunk of his movie to a dark, didactic and altogether horrific evocation of Vietnam, complete with napalm, Agent Orange and helicopter gunships (one of which is named Valkyrie in a tip of the helmet to 'Apocalypse Now.') Whatever one may think of the politics of this antiwar section, two things can be said with certainty: it provokes an adrenaline rush (what that says of our species is another matter), and it feels a lot better when it's over.

　　 Other narrative problems intrude. For all its political correctness about the goodness of the Na'vis, 'Avatar' lapses into lurid savage rituals, complete with jungle drums, that would not have seemed out of place in the first 'King Kong.' While Ms. Weaver's performance is a strong one, it isn't clear what her character is doing as an avatar, or how the Na'vi perceive her. What couldn't be clearer, though, is that Mr. Cameron's singular vision has upped the ante for filmed entertainment, and given us a travelogue unlike any other. I wouldn't want to live on Pandora, mainly because of the bad air, but I'm glad to have paid it a visit.