Seth Green

Seth Green moves, but doesn’t speak, in ’Mars Needs Moms’

If you’ve caught any of the promotion for "Mars Needs Moms," you’re probably under the impression that Seth Green has a major role in the Robert Zemeckis-produced science-fiction movie that opens Friday.

After all, Green’s name and cartoon visage are featured on the poster for the 3-D performance-capture film, and the actor has made appearances on behalf of the animated movie, posing on the red carpet at the film’s premiere and sitting for an interview on "Conan." Casual fans could be forgiven for thinking he voiced his character, the 9-year-old Milo.

But while Green’s movement is represented in the movie, his voice never is.

During production, the star acted as he would in any performance-capture movie, which requires actors to move in special sensor-equipped suits. Green spent six weeks outfitted in a uniform to play the child protagonist whose mother is kidnapped by Martians (you can see a shot of the get-up above), while also simultaneously performing his lines.

But during the post-production process, in which animators used computer imaging to shape the character, filmmakers noticed an issue. Green was able to physically embody a 9-year-old — imitating the movements and behaviors of a child — but his voice sounded too mature for the character. So they decided to hire an unknown child actor, Seth Dusky, 11, to come in and record all of Milo’s lines over Green’s initial recording. (Dusky’s name is not featured on the poster.)

In an interview on Tuesday, Green said he was always aware of the possibility that his voice might not end up in the final cut. “There was always a consideration that the character would be redubbed by an actual kid,” he said.

Green added that the filmmakers explored other solutions. "There was a thought to doing some kind of vocal modulation digitally, but the truth is that this is about creating an illusion," he said. "These characters, while animated, are very real, and you don’t want any distraction from the audience thinking that this is an adult whose voice has been modified."

The actor maintained he was proud of the project, going to great lengths to convey that he harbored no ill will toward the filmmakers over the vocal switch.

"I don’t feel like I’ve been replaced or like my performance is invisible. It wasn’t like I did anything wrong and someone was saying my performance wasn’t good," said Green, adding that he met Dusky for the first time at the film’s premiere last weekend.

Director and co-writer Simon Wells told my colleague John Horn that the filmmaker and his wife (co-writer Wendy Wells) decided to swap out the voice for reasons of authenticity. Even if "Seth’s performance made us cry" — particularly in the scene where Milo’s mother saves him — Simon Wells said that he and Wendy were aware they were listening to the voice of "a 37-year-old man."

While Disney may not be touting the vocal change-up, the studio isn’t trying to hide it either. The film’s press notes mention that Dusky lent his voice to the film, and Simon Wells emphasized the importance of Green’s performance-capture role. "Dusky faithfully followed every nuance of Seth Green’s performance," Wells says in the notes, adding that the character was "all guided by Seth Green’s sincere and brilliantly convincing performance."

Still, Green’s altered role highlights the murkiness surrounding effects-enhanced movies, where an actor’s role is often less defined than in a traditional live-action film.

“It’s all difficult to explain to people because the process is so unfamiliar to people in the audience,” Green acknowledged. “But I’m just so proud of the movie that I don’t want anything to get in the way of people receiving it, you know?”