Serkis already joined "Age of Ultron" as a consultant through his motion-capture company, The Imaginarium.
Speaking of his involvement in the Marvel movie as well as in "Star Wars episode VII", the actor told Variety: "I'm playing a role (in both films). On 'The Avengers', I've been working closely with Mark Ruffalo."
When asked whether or not his face would appear in the movie, Serkis said, "I'm not at liberty to mention. But it's all the same to me. I've never drawn a distinction when playing a role, whether it be live action or performance capture. Acting is acting. It's just basically what you wear to the set that's different.