James McAvoy is sure people will be disgusted by his latest movie venture.James McAvoy is banking on people "walking out" of controversial new movie Filth.Playing Bruce Robertson, a cop investigating a murder while at the same time exploring the depths of his own mental health, the film sees James taking on a complex character.He's sure it won't go down well with everyone."There are going to be people who'll walk out," he said to Empire magazine."I think whatever you think of it, you're going to have a reaction."Filth is based on the book by author Irvine Welsh, who also penned Trainspotting and tackles the same gritty themes of sex and drugs, as well as mental illness and physical deterioration. James deviates from the normal characters that he portrays on the big screen, and dips into the world of being a vicious, nasty junkie."It's kind of f**king hilarious to play," he revealed. "You're playing someone who thinks they're the most important person in the world."I just thought Bruce was fascinating character, it's one of the best scripts I've ever read and it's an incredible film."James had to work hard to convince Irvine that he was right for the part.Ultimately, the character of Bruce had to be adjusted to work on the big screen."You're fascinated by Bruce and everything he does, but you don't feel for him in the book," he explained."You can't really do that on film. You want to relate somehow. Of course, that's not to say we're making him nice, but I do think you wind up with some sort of... understanding of him."