Australian actor Sam Worthington plays Avatar's hero, a paralysed marine
UK cinema-goers are being given a taste of James Cameron's new science-fiction epic Avatar at free previews taking place around the country.
They are being shown 15 minutes of the futuristic fantasy, which uses motion-capture animation, CGI and live action, and will be shown in stereoscopic 3D.
One of the day's first sneak previews was held at the BFI Imax in London, home to the UK's biggest cinema screen.
A trailer from the film, released on 18 December, is now available online.
In a filmed introduction, Cameron tells audiences all the excerpts come from the first half of his movie.
Avatar is the 55-year-old's first full-length feature since 1997's Titanic, which won the Canadian filmmaker a best director Oscar.
Warning: If you do not want to know about the Avatar footage, stop reading now.
An expectant audience gathered at the BFI Imax on Friday morning, to be greeted by BFI director Amanda Nevill and Chris Green from distributor 20th Century Fox.
Cinema-goers give their opinions on the Avatar preview at the BFI Imax in London
Avatar, said Green, was a "really special project" with an "amazing" story enhanced by state-of-the-art technology.
Set in the 22nd Century, Cameron's film takes place on a distant planet called Pandora inhabited by a humanoid race with its own language and culture.
Humans cannot breathe the air on Pandora so have created avatars - hybrid creatures controlled via a mental link by a human operator.
The footage begins with paralysed marine Jake Sully arriving on the planet to be told he and his fellow soldiers have a limited chance of survival.
"My mission is to keep you alive," says a tough-talking colonel, played by Stephen Lang. "I won't succeed."
Sully then meets a scientist, played by Aliens star Sigourney Weaver, who places him in a cocoon resembling a space-age sunbed.
It is this that places his mind inside a Na'vi - a ten-foot-tall, blue-skinned creature with the ears of a deer and a long, curling tail.
James Cameron: "Avatar is the film I always wanted to make."
So captivated is Sully by his new form that he wastes no time on preliminaries, breaking out of hospital to the dismay of his handlers.
Later scenes show his avatar interacting with Pandora's large and mostly hostile creatures - among them a ferocious, six-legged beast and a hammer-headed, rhino-like dinosaur.
He also encounters a female Na'vi warrior, voiced by Star Trek's Zoe Saldana, who is dismayed by his cavalier attitude to other life forms.
The preview ends with Sully mastering a winged, dragon-like pterodactyl that takes him on a whirlwind aerial journey.
It is here the footage literally takes flight, Cameron whisking his audience into the skies, through waterfalls and down cavernous ravines.
Londoner Seb King said the result was akin to "riding a simulator".
The film reunites Cameron with Aliens star Sigourney Weaver
"I felt sick watching the 3D footage," said Mr King, who was nonetheless impressed by the "fantastic" visuals.
At first glance, Cameron does appear to have created a bold, impeccably-realised new world.
The frenetic jungle-based action feels a little familiar, however, especially if one has seen Peter Jackson's 2005 King Kong remake.
Steeped in machismo and testosterone, the dialogue also seems in keeping with this director's previous action adventures.
"Let's dance!" says Sully as he mounts his winged steed, firmly ordering the creature to "shut up and fly straight".
The result resembles an elaborate video game, set amid lush vegetation that turns luminescent after dark.
Unsurprisingly perhaps, computer giant Ubisoft will release a tie-in game when the movie hits cinemas later this year.
We asked for your reviews of the Avatar trailer and preview. Please find a selection of your comments below.
I went to the world's first screening at the BFI Imax, and I felt sick watching the 3D footage. The use of stereoscopic 3D and the CGI motion-capture does not work well with Cameron's swooping, jerky camera movements. It feels like you're riding a simulator rather than viewing a film. That said, the visuals are fantastic - a real leap forward in film-making technology. Seb King, London, UK
I watched the teaser trailer yesterday after months of hype and it definitely delivered. The CG environment is stunning and this is surely to be the next step in 3D technology. Going to watch the footage later so will see how good the technology really is. It's 14 years in the making so I know it will be amazing!! James L, Sheffield
Just seen it - pretty amazing. Been following Avatar for the past two years - only slightly disappointed that when the camera moves it becomes pretty blurred and it's hard to focus. That said, the scenes where the camera doesn't move so much are amazing Paul Dixon, London
James Cameron has made an original epic that looks visually stunning and beautiful. I was sceptical about 3D technology until I saw Avatar footage first hand at movie-con 09 and was pleased to find my senses being spoon fed something truly special and unique. Lets hope the four years in production and $200m budget make it as epic as we expect. Lawrence Cooke, Staines
I have seen the trailer on High Definition and thought it looked amazing. I cannot wait to see it on the big screen in December! It's great to have something new and different to look forward to. Alexandre, London
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