Ben Affleck's younger brother CASEY is so determined to be a successful actor - he faced death trying.

The 27-year-old, who had a role in OCEAN'S ELEVEN, almost met his end in California's brutal Death Valley while filming the independent movie GERRY.

The scene called for his character to hallucinate from heat-stroke.

To make it realistic, Casey had assistants drive him into the middle of the desert - and leave him.

Casey recalls, "I didn't drink water all day. It was like, 20 minutes, and I was on my butt on the side of the road."

Casey phoned for help, but then began having strange delusions.

He says, "I really believed that I had called them and they weren't coming to get me because they wanted me to die.

"I panicked and then everything slowly went dark."

Crew members went to dehydrated Casey's aid just in time, and they immediately plied him with fluid.

Set sources say Casey was like a "zombie" for almost two days after the incident.