LOS ANGELES - The release of "The Adventures of Tintin" trailer last week revealed the look of director Steven Spielberg's long-gestating adaptation of the popular European comic series. The story of an intrepid young reporter on a hunt for a ship's treasure inspired by the work of Belgian artist Herge, "Tintin" was shot in a shadowy film-noir style using the same performance-capture technology that James Cameron deployed on "Avatar."

The trailer's scenes of photo-real characters adventuring in an animated world raise anew a question that has bedeviled the Academy of Motion Picture Arts and Sciences in recent years: how to treat films that use performance capture, or motion capture, as the technique is also called. Relying on both actors and animators to tell its story, "Tintin" is one of a growing category of movies that don't fit neatly in either the animation category or live action.

"You'll never be able to define an animated film by how it looks, 'cause we're using the same artists, the same software, the same computers to do very cartoony stuff and very photo-real stuff," said Bill Kroyer, a governor of the academy's short films and animation branch. "Where are you going to draw the line? You can see how this is going to become an increasing problem. From our standpoint, it's about preserving a specific art form."

With star power such as Spielberg and producer Peter Jackson behind it, "Tintin" looks likely to receive awards-season attention, and if it does, Spielberg would like it to be in the animated category, according to a spokeswoman at Paramount Pictures.

"In a year filled with sequels, ['Tintin'] should stand out for its originality," said Bill Desowitz, senior editor of the Animation World Network, an animation publishing group.

The academy amended its rules in 2010 to address motion capture. Besides "Avatar," the technique has been used on films including "Polar Express," "Happy Feet" and the "Lord of the Rings" trilogy. To make these films, actors wear body suits with markers, and cameras record their movements. Then visual-effects artists and animators add to the actors' performances.

"Motion capture by itself is not an animation technique," the academy rules stipulate. "In addition, a significant number of the major characters must be animated, and animation must figure in no less than 75 percent of the picture's running time."

"If it was intended to simply be a copy of a live actor's work, then we would not consider it animation," Kroyer said. "At the moment, we have not determined a way to make that decision. It lies with the intention of the director."