LONDON — Jennifer Aniston is confirmed to join Mark Duplass and Ben Kingsley in surreal sci-fi comedy “Convention,” which K5 International will be selling at the EFM in Berlin.Aniston had long been rumored to be circling the project, which locked Duplass and Kingsley last May. Aniston will play Duplass’ sister as the pair inadvertently rip a hole in the fabric of the universe after he invents a five-sided box, to revolutionize the box storage world, which defies the laws of physics. Kingsley plays a maniacal, rival box magnate. The film, described as “Kaufman-esque,” is the sophomore feature effort of commercials helmer Justin Reardon, who recently finished lensing his debut feature “A Many Splintered Thing,” starring Chris Evans and Michelle Monaghan. “Convention” is scripted by Christopher Painter, and produced by Paul Schiff and Tai Duncan.