Robert Pattinson has fellow Twilight hunk Kellan Lutz to thank for his big film breakthrough - because the American turned down the role of vampire Edward Cullen.

Lutz had just returned to America after shooting gritty war mini-series Generation Kill in Africa, and he wanted a break when his agent put him forward for the lead role in Twilight.

"I was there (in Africa) for seven months, killing people, playing a Marine. (It was) really depressing, it burned me out.

"They sent me the script and I was like, 'I don't like working when I'm working...' I finally read it because they nagged and nagged and nagged. (I) finally got back to L.A. and they were like, 'Are you ready to audition for Edward?' and I said, 'No, I'm taking a vacation. I wanna break.'

"So I went back to Arizona, saw my mom and they got really p**sed because I didn't tell them. They booked an appointment and I just said, 'I don't wanna play Edward, he's too complex, he's too depressing for me.'

"They kept on calling... and then they called a week later and said. 'What about (character) Emmett (Cullen)?' and I re-read the script and Emmett had four lines... and he seemed like one of those fun-loving characters that I love to play."

So Lutz flew to Oregon for an audition, won over director Catherine Hardwicke and she sent him to "baseball try-outs".

The actor is still convinced he made the right decision not to try out as Edward after seeing how difficult life has become for his movie brother.

Speaking on DJ Ryan Seacrest's Los Angeles radio show, he says, "Fame is fame and Rob is handling it like a champ... but I don't think anyone could prepare for something like this. I'm so happy with Emmett... I don't care to be famous."