If you are only as successful as your last movie, then it's no wonder James Cameron took a 12-year hiatus from filmmaking – he must have been thinking, 'how am I ever going to beat raising the Titanic?'

Enter Avatar. Now we saw the preview footage a few months ago and weren't that impressed, so how does the final movie compare? And more to the point, does all the 3D technology actually, finally deliver?

Yes, it really does. Avatar doesn't just change your perception of what cinema can do, but finally brings the concept of 3D into the 21st Century.

From its opening moments, you can understand just what Cameron has been doing while he's been away. He's been busy creating his own fully realised world – Pandora.

The planet is full of lush vegetation, primal creatures and a population of blue Na'vi warrior aliens, whose beliefs and way of life are being torn apart by an army assigned to displace them and plunder their land for fuel.

Jake Sully (Sam Worthington), a paraplegic marine, is chosen after the death of his twin brother to infiltrate the Na'vis. Due to Pandora's air being poisonous to humans, his mind is mapped to a specially created Na'vi avatar, and his mission is to understand how they live and find a way to move them from their homes humanely.

If he fails, then there's only one thing for it – an almighty ruck between the natives and the marines.

Emotion capture

Flitting between the 'real' world of the marines and the digitised world of the Na'vi's, Cameron shows in each pixel-populated scene just how much time he and his team of effects supervisors have taken to make sure that Avatar is the most accomplished SFX movie seen to date.

To create the blue, gangly, Na'vi's, the director hasn't just used motion capture, but 'emotion' capture. Utilising technology for the first time which maps an actor's eyes as well as their body, there's a stunning amount of pathos in the aliens which populate the planet of Pandora. So much so, the supporting human cast sometimes seem two-dimensional compared to their sumptuous CGI counterparts.

And while we are on the subject of dimensions, it has to be noted that Avatar is a movie that needs to be seen in the third dimension and on the big screen. Never has donning a pair of glasses meant so much to a film.

While 2009 has definitely seen some great 3D films – Monsters Vs Aliens and Up being standout – Avatar will undoubtedly become the benchmark that every 3D movie from now on will be compared.

Moving the technology on from gimmick to necessity is no easy task, considering 3D has been around for nearly as long as cinema itself, but Cameron has managed it by going back to the drawing board and creating new cameras – including virtual ones which helped him see what was taking place in his CG world in real-time – and camera rigs to integrate the tech with the filmmaking process, rather than drop it in as an afterthought.

It works, and can be seen in every so-real-you-can-touch-it drop of water, every rustle of leaves and each smoke bomb and bullet which jump from the screen.

Visually stunning

If only as much time was spent on the script as the effects, Cameron's film would be regarded as a masterpiece. Unfortunately, an in-your-face eco message, some clunky dialogue and misjudged hippy motifs – which see the Na'vis literally jacking into nature – mar what is a visually stunning piece of cinema.

Luckily the last 40 minutes more than make up for the script-writing foibles. A barrage of heartache and violence, redemption and revenge culminates in a face-off that's every bit as great as when Ripley blasted the Alien queen into space – also under Cameron's guidance – some 20 years before.

A lot has happened since Titanic hit screens in 1997. A new Star Wars trilogy has been and gone, and franchises like The Lord of the Rings and Harry Potter have brought the concept of fantasy into the mainstream once more.

Does this mean that the stage is set for Avatar to break the box-office in the way Titanic did? No. Its story is too niche to find such a broad audience, regardless of how much marketing goes into the movie.

But not everything in cinema is about money. Sometimes it's much more than that. It's about driving moviemaking forward, transporting audiences to places they have never been before and showing other filmmakers a new way to ply their trade.

Avatar does this and more. Although not perfect, it's a film which will change movies (both watching and making them) forever, and in the process open everyone's eyes to the fact that maybe there's something to this 3D malarkey after all.

Avatar is in cinemas nationwide from 17 December, courtesy of 20th Century Fox.