Robert Pattinson, center, with Nikki Reed and Kellan Lutz are part of a vampire clan in Twilight.

LOS ANGELES TIMES / SPENCER WEINER

HOLLYWOOD — Robert Pattinson has all the traits of a Hollywood heartthrob — photogenic features, a lovely British accent and a starring role as the brooding but devastatingly handsome good guy vampire Edward Cullen in Twilight, the big-screen adaptation of the first installment in author Stephenie Meyer’s wildly successful young-adult book opening today.

The only thing that doesn’t quite fit? Pattinson is one seriously self-deprecating guy.

“I can’t watch myself on screen,” said the 22-year-old actor, who previously appeared as Cedric Diggory in the Harry Potter films. “When my parents say, ‘Oh, did you see this photo?’ I immediately start going, ‘Don’t tell me about photos!’ I haven’t watched anything since the premiere of Harry Potter. And that’s because I couldn’t find a way out.

“It would have looked a bit bad for me to walk out,” he conceded with a laugh.

In the coming months, Pattinson and the rest of the film’s ensemble cast are probably going to have to get a lot more comfortable with fame. Twilight, which details the romance between Edward and 17-year-old Bella Swan (Kristen Stewart), has been compared to Romeo and Juliet, with its themes of forbidden love. But it’s also been described as the heir to J.K. Rowling’s teen wizard saga — given its blockbuster literary pedigree and popularity among the under-18 set. For months, interest in the film has been building: There was even a clock counting down the minutes to its premiere at twilighthemovie.com.

It’s a strange thing to realize that you’re at the heart of a full-blown pop culture phenomenon, but on an unseasonable October afternoon, with the temperature hovering near 100 degrees, the pressure didn’t seem to be adversely affecting any of the actors. Gathered around a conference table in a Los Angeles office building, Pattinson and costars Kellan Lutz and Nikki Reed, who portray two other members of the Cullen clan, were playing it remarkably cool.

“I think it was toward the end of shooting when it really dawned on me,” said Reed, who plays the supremely confident Rosalie, love interest to Lutz’s Emmett. “There were fans that were finding out where the locations were, and that’s when it really hit me. People saying, ‘Oh, it’s going to be the next Harry Potter!’ That’s a big mountain in front of you. There’s a lot of hype around this.”

During the conversation, the trio easily dissolved into laughter, teasing one another and displaying the same generally convivial vibe that took root during the weeks they spent together on set in the remote Pacific Northwest with director Catherine Hardwicke.

“It’s weird having such a big cast where everyone’s pretty much the same age,” Pattinson said. “A lot of the time the locations were really isolated, so we were the only people we could hang out with.”

Every modern take on the vampire legend sets up new rules that govern the creatures, and Twilight is no exception. The Cullens refuse to feed on humans, hunting animals instead, and they are not harmed by the sun, although their luminous white skin does glitter in direct light. It’s their self-imposed dietary restrictions and desire to live among people that ultimately helps Bella accept Edward’s true nature, but it also puts the vampires in direct conflict with others of their kind, who are less, well, civilized.

For the movie’s action sequences, the actors experimented with stunts and wire work, which Pattinson admits did not play to his strengths. “I got injured on the first shot of the first day,” he said. “I wasn’t even doing a stunt. I was just trying to pick up Kristen and I almost tore my hamstring because I hadn’t been doing enough squats. It was very embarrassing.”

Added Lutz: “When we did have those hard days, we would go back to Rob’s room. He had a couple of guitars in there and a lot of great music. It was really fun being able to relax and have the cast come together, having that time just to bond and not really be actors but friends.”

Summit Entertainment already has announced plans to move ahead with adaptations of the other books in the series — depending, of course, on how well Twilight fares at the box office.

Pattinson, Lutz, 23, and Reed, 20, said they are thrilled about the prospects for a Cullen family reunion. After all, playing a vampire does offer an actor certain advantages.

“It’s quite cool having this sort of secret element,” Pattinson offered.

“You’re doing a scene with someone and you can play something however you want and deliver it in a completely random way so even the other actor doesn’t know what you’re doing.

“And you can just say, ‘Well, it’s because I’m a vampire, isn’t it?’ ”