The big-budget film "Tropic Thunder," starring Ben Stiller, is moving forward on Kaua'i. Cameras are set to roll from mid-July to mid-August, and now the production crew is ready to cast locals as extras.

Kaua'i residents are buzzing about the prospect of having a major Hollywood film in their midst, said Art Umezu, Kaua'i film commissioner.

Besides Stiller, who is also the director, the $100 million comedy has a high-profile cast that includes Tom Cruise, Jack Black and Robert Downey Jr.

The project is described as a movie within a movie. The plot: Unexpected circumstances turn an on-location set for a Vietnam-esque war movie into a real battle zone. Several hundred Kaua'i natives are to play villagers.

"Essentially, most Kaua'i people are nonchalant because of past filming of 'Raiders of the Lost Ark' and 'Jurassic Park,' " Umezu said. "But now there's a buzz, because everywhere, somebody or others affected — some neighbor, some cousin, a friend is working as a laborer, extra, actor. Everyone's talking about Hollywood."

Umezu believes that the state's Act 88, which gives moviemakers the incentive of a 20 percent tax break on the Neighbor Islands, was a key factor in luring "Thunder" to the Garden Isle.

It probably also doesn't hurt that Stiller owns a home on the island.

"Thunder" will be largely shot on private Grove Farm land, in central Kaua'i, so the curious and paparazzi will not have easy access.

"There has been a lot of activity leading up to the launch," Umezu said.

"They renovated a dilapidated warehouse, which now is beautiful, and they'll build a village in the mountains."

The DreamWorks-Red Hour Films production is now looking for local actors, with auditions today and June 23.