AMPAS amended its rules in 2010 to address motion capture. In addition to "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 a body suit with markers, and cameras record their movements. Then visual effects artists and animators add to the actor's performance.

"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% of the picture’s running time."

"Tintin" relies on motion capture performances for most of its major characters, including Tintin, played by Jamie Bell, a pirate (Daniel Craig) and a pair of bumbling detectives (Simon Pegg and Nick Frost). But animators are working with those performances -- Pegg and Frost, for instance, who are physical opposites in real life, play twins.

"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."

In the case of "Avatar," Cameron chose to campaign his film, which relied on such actors as Zoe Saldana and Sam Worthington and on animators at Weta Digital to create its tall, blue characters, as live action.

By calling "Tintin" animated, Spielberg, who will also have the live action film "War Horse" in awards contention this year, is stepping into an industry debate about the motion capture technique.

In 2006, the motion capture movie "Happy Feet" won the animated feature Oscar, inspiring a backlash against the technique among animators who consider it either disempowering or cheating. The credits of the Pixar movie "Ratatouille," released the following year, included the prickly disclaimer: "Our Quality Assurance Guarantee: 100% Genuine Animation! No motion capture or any other performance shortcuts were used in the production of this film."

"You have opinions that run the entire gamut," said Kroyer. "You have people who are prophets of motion capture  and other people who say it’s heresy and I will never use it. I think mo-cap is as legitimate a tool as anything for making films, but it’s not the kind of animation we always did."

The motion capture Oscar debate is not likely to go away any time soon -- Jackson's "The Hobbit: Part 1," which will rely on the technique for some characters, is due in 2012, a second "Tintin" movie is currently slated for 2013 and "Avatar 2" is coming in 2014.