Tropic Thunder stars Ben Stiller, Jack Black, and Robert Downey Jr. gave an advanced screening on Sunday of their upcoming action-comedy for U.S. troops at Camp Pendleton.

The actors arrived at the California military base on Sunday by helicopter and then loaded into military humvees to make their way down a combat green carpet to the MCC Base Theater where the trio shook hands with troops, posed for pictures, and introduced Tropic Thunder to hundreds of Marines, sailors, and their guests.

Ben Stiller, Jack Black, and Robert Downey Jr. lead an ensemble cast in this action comedy about a group of self-absorbed actors who set out to make the biggest war film ever. After ballooning costs (and the out of control egos of the pampered cast) threaten to shut down the movie, the frustrated director refuses to stop shooting, leading his cast deep into the jungles of Southeast Asia for “increased realism,” where they inadvertently encounter real bad guys.

“We were really excited to show this movie to the military personnel who do so much for our country,” said Ben Stiller, who also wrote and directed Tropic Thunder. “I think they really got a kick out of seeing a bunch of spoiled actors complaining about how hard it is to do a war movie. But seriously, it was really hard. We almost did a boot camp, but then decided on a cast dinner instead.”

Tropic Thunder will be released nationwide on August 13, 2008.