Matthew McConaughey has jumped into the ensemble cast of “Tropic Thunder,” the Ben Stiller-directed DreamWorks comedy.The job amounts to an uncredited cameo, as McConaughey takes the role that Owen Wilson ankled after he was hospitalized (Daily Variety, Aug. 29). McConaughey joins an ensemble cast that includes Stiller, Jack Black, Robert Downey Jr., Nick Nolte, Bill Hader and Steve Coogan. Pic’s about a group of actors who gather on a remote island to shoot a big-budget war movie and are forced to become the soldiers they are playing. McConaughey, who this year finished the Andy Tennant-directed “Fool’s Gold” and the S.R. Bindler-directed “Surfer Dude,” carved out a week in his schedule to shoot the role. Pic is lensing in Hawaii.