James Cameron's long-awaited "Avatar," one of the most expensive films ever made, takes off this week in an awe-inspiring display of Hollywood power that has revolutionized cinematic special effects.

At a cost of about $400 million to make and market "Avatar," the Oscar-winning director of "Titanic" has created a lush world of dense forest, floating mountains and tremendous creatures in a computer-generated spectacular that transforms much of the cast into giant, blue-skinned humanoids.

The movie, which premiered in London on Thursday and begins landing in theaters worldwide next week, represents a huge risk for the 20th Century Fox studio that backed it and is being watched closely in Hollywood for its impact on the future of movies, special effects and expansion of new 3D technology.

"It's absolutely cinema, but I think cinema redefines itself every few years with new techniques," Cameron told reporters in Paris before the film's launch.

Beyond dazzling audiences with visual effects that plunge the viewer onto the planet Pandora 4.4 light years from Earth, "Avatar" provides a familiar mix of romance, action movie thrills and an old-fashioned battle between good and evil.

"The more fantastic the subject ... the more recognizable and universal, the relationships and people need to be," Cameron said.

"Avatar" shows the forest-dwelling Na'vi fighting for survival against a rapacious colonial mining operation bent on moving them away and stripping their planet.

A crippled ex-Marine is chosen to make contact with the mysterious people as an avatar, a remotely controlled body, which allows him to move freely in the alien world where he falls in love with a Na'vi princess.

SCIENCE FICTION TECHNOLOGY

What makes "Avatar" stand out, however, is the appearance of its three-dimensional forest scenery and the seamless interaction of the human cast with the animated world.

James Cameron's long-awaited "Avatar," one of the most expensive films ever made, takes off this week in an awe-inspiring display of Hollywood power that has revolutionized cinematic special effects.

At a cost of about $400 million to make and market "Avatar," the Oscar-winning director of "Titanic" has created a lush world of dense forest, floating mountains and tremendous creatures in a computer-generated spectacular that transforms much of the cast into giant, blue-skinned humanoids.

The movie, which premiered in London on Thursday and begins landing in theaters worldwide next week, represents a huge risk for the 20th Century Fox studio that backed it and is being watched closely in Hollywood for its impact on the future of movies, special effects and expansion of new 3D technology.

"It's absolutely cinema, but I think cinema redefines itself every few years with new techniques," Cameron told reporters in Paris before the film's launch.

Beyond dazzling audiences with visual effects that plunge the viewer onto the planet Pandora 4.4 light years from Earth, "Avatar" provides a familiar mix of romance, action movie thrills and an old-fashioned battle between good and evil.

"The more fantastic the subject ... the more recognizable and universal, the relationships and people need to be," Cameron said.

"Avatar" shows the forest-dwelling Na'vi fighting for survival against a rapacious colonial mining operation bent on moving them away and stripping their planet.

A crippled ex-Marine is chosen to make contact with the mysterious people as an avatar, a remotely controlled body, which allows him to move freely in the alien world where he falls in love with a Na'vi princess.

What makes "Avatar" stand out, however, is the appearance of its three-dimensional forest scenery and the seamless interaction of the human cast with the animated world.