Ubisoft showed off its work with one of Hollywood’s most technology-minded directors, James Cameron, at a press conference at the E3 game conference today in Los Angeles. 

Ubisoft’s flagship title this year is Avatar, a game based on Cameron’s high-profile movie. Cameron came out on stage and went through a lengthy description of Avatar, which debuts Dec. 18. He has been working on the movie for more than four years and first conceived the idea of doing the film, which has photorealistic computer-generated characters, more than 14 years ago.

The action of the film takes place on a distant planet full of rainforests. It pits humans armed with technological weapons against a race of 10-feet-tall aliens who ride exotic creatures into battle. The avatars in question are not synthetic characters but rather humanoid creatures who can breathe the air of the alien world. Ubisoft’s creative team, supplemented by the Hybride movie special effects team that Ubisoft acquired, has actually contributed more than 100 special effects shots to the film. The game will have its own storyline that is separate from the movie’s, Cameron said. Sadly, Cameron walked off stage without showing scenes from either the film or the game.

Ubisoft is also making a game based on a new Paramount movie, TinTin: The Secret of the Unicorn, which debuts in December 2011. Ubisoft will work with director and producer Steven Spielberg, producers Peter Jackson and Kathleen Kennedy, to make a game tied to the movie. 

Paris-based Ubisoft, the third largest independent game company, also touted Red Steel 2, a sword-fighting and gun-slinging Western game that will be bundled with the Wii MotionPlus accessory, which makes the Wii remote more accurate. The original Red Steel, which debuted in 2006, was kind of a bad joke because the Wii controller was too inaccurate to handle a shooting and slicing game. But the slicing and shooting in Red Steel 2 look like they’ll make up for the horrible experience of the first game.

Ubisoft will also launch a reprise of its Wii hit, Shaun White Snowboarding. The game featuring the goofy red-haired snowboarding champion sold more than 2.8 million copies last year.

Every company trots out stars at E3. Ubisoft’s second big name at the event was internationally known soccer star Pele. Pele spoke about the game, Academy of Champions Football, which is rendered in a cartoon style and features larger-than-life athletes who perform all sorts of crazy soccer tricks.

Ubisoft showed the same Tom Clancy’s Splinter Cell Conviction trailer that Microsoft played at its press conference. The game is about Sam Fisher, a clandestine agent who goes on a murderous spree in search of his daughter’s killer. The graphics are amazingly detailed, but the game appears to give up a little bit of interactivity and some speed in exchange for the gorgeous graphic detail.

But Ubisoft’s casual titles, aimed at kids and young teens, are cleaning up. Tony Key, senior vice president at Ubisoft in the U.S., said the so-called tween titles are selling by the millions as girls pick up the Nintendo DS to play a variety of pet and fashion games. Ubisoft is now launching Style Lab, where you can create your own fashions, upload them to Ubisoft’s site, and then purchase them.

Ubisoft had a ton of new titles to show off, from a fitness game with a video camera to a new Raving Rabbids game, dubbed Rabbids Go Home. But the big game of the day, shown at the end, was Assassin’s Creed II, the sequel to the 2007 game that sold eight million units. The game is set in the Renaissance and has a playable version here at the show. It’s another stealth game, akin to the Tom Clancy games, but set long ago.