NEW YORK – Robert Pattinson was nearing the end of shooting the last “Twilight” film, concluding a chapter of his life that had picked him out of near obscurity and was preparing to spit him out … where exactly?

“Twilight” had made him extravagantly famous, but his next steps were entirely uncertain.

“Out of the blue,” he says, came the script for “Cosmopolis” from David Cronenberg, the revered Canadian director of psychological thrillers (“Videodrome,” “Eastern Promises”) that often pursue the spirit through the body. Pattinson, having never met or spoken to Cronenberg, did a little research: He looked him up on Rotten Tomatoes “and it was like 98 percent approval,” he says.

“It was like: OK, that’s my next job,” says Pattinson.

Pattinson now has the unenviable task of releasing his most ambitious movie, his most adult role. It is a film that, in an earlier interview before it premiered at the Cannes Film Festival, he said “changed the way I see myself.”

At 26, Pattinson may be one of the most famous faces on the planet, but he’s still getting his bearings as an actor – a profession, he says, he never pined for, fell into by chance and has always found uncomfortable. His unlikely trajectory began with “Harry Potter and the Goblet of Fire” and “Little Ashes,” in which he played Salvador Dali.

“Then I got ‘Twilight’ and it suddenly became a massively different world to navigate,” Pattinson said in a recent interview in New York. “Most people who get their big hit have figured out what their skills are, and I hadn’t, really.”

“Cosmopolis” is a radically different kind of film that will surely confuse not only the hordes of diehard “Twilight” fans who will line up to see it, but art house moviegoers, too. Pattinson himself has watched it four times to try to get his head around it.

The first movie adaptation of a Don DeLillo novel, “Cosmopolis” is about a sleek financier, Eric Parker (Pattinson), slowly making his way in the airless sanctuary of his white stretch limo across a traffic-jammed Manhattan with the simple goal of a haircut. But the journey, which includes visits with his new wife (Sarah Gadon), another woman (Juliette Binoche) and Occupy-like protesters (Mathieu Amalric), is a kind of willful unraveling for Parker, who dispassionately watches his fortune slide away on a bad bet on the Chinese yuan.

“He’s an egomaniac who wants to see some kind of spirituality in his egomania,” says Pattinson. “It’s kind of like how actors feel about themselves.”

Pattinson is in every scene of the film, which relies on his callow, hyper-literate performance to carry the movie through its limited setting and DeLillo’s heightened dialogue – much of which Cronenberg transcribed verbatim from the novel. Though some reviews have found the film static and impenetrable (perhaps intended responses), most critics have praised Pattinson’s performance, with many citing it as proof that the heartthrob can indeed act.

The stylized language and atypical nature of the film made it a risky and intimidating choice for Pattinson.

“I couldn’t hear the voice of the character at all. There was nothing,” he says. “It was scary to say yes to something which you didn’t know what it was. I knew it was interesting, I knew there was something special but I had no idea how to do it or what I could add to it. But when you start saying no to Cronenberg because you don’t think it’s good enough, it’s a stupid decision to make.”

It’s clear that his “Twilight”-fueled celebrity weighs heavily on Pattinson, who says he knows people watch his films “through a cultural context.”

“Rob, he’s popular,” says Cronenberg with deadpan understatement.

“I couldn’t have cast Rob without ‘Twilight’ just as I couldn’t have cast Viggo (Mortensen) without ‘Lord of the Rings,’ ” says the director whose previous three films – “A History of Violence,” “Eastern Promises,” “A Dangerous Method” – starred Mortensen. “The fact that somebody who has clout is willing to do a movie that’s difficult is a gift to a director because you’re not only getting the right guy as an actor, but you’re getting financing interest and you get to make the movie. This is not an easy movie to get made.”

Pattinson seems energized by the freedom of choice in front of him following the final “Twilight” installment in November. He’s lined up parts in films far from blockbuster size: “Mission: Black List,” a military thriller, and “The Rover” by Australian director David Michod (“Animal Kingdom”), a role he says he fought for more than any before.

Embarking on “Cosmopolis” appears to have been a process of letting go for Pattinson – of self-awareness, of worry, of fear. Asked if he now feels certain he’s an actor, he quickly replies, “No.”

“As soon as you start existing in a certain world, you feel like you have tremendous amount of baggage all the time,” he says. “You get stuck in this rut where you want people to think you’re something else, but you’re too scared to do what that is to actually be the other person.

“Then you get a gift like this movie where it’s way easier than I thought it was,” he says. “You just do it. It doesn’t really matter if you fail.”