(Cover) - EN Showbiz - Olivia Wilde has no problem with nudity in movies, because she thinks it's vital to give 100% to roles.

The actress bares her body in two pictures released this summer, Cowboys & Aliens and The Change-Up. She didn't even realise she flashed her flesh in the latter movie until some people who'd seen it let her know, but insists it doesn't bother her. Olivia believes in fully immersing herself in the characters she plays, so stripping off is no big deal for her.

"With The Change-Up I didn't really realise that's what was happening, as if I didn't really know where the camera was. So then people saw the movie and they're like, You know your butt's in the movie?' and I was like, What?'" she explained. "I had no idea! But you know, I think when you agree to do a movie, like that you have to go 100% for it!"

The Change-Up is about two men who accidentally switch bodies, while Cowboys & Aliens is about a group of cowboys who have to save the world from extra-terrestrials.

Olivia is Ella Swenson in the sci-fi romp, and was more than happy to show off her body. She explained the scene fitted in well with the story, which is something she looks for when it comes to appearing nude on screen.

"There's a little nudity in this one," she laughed to Access Hollywood. "There is [a little butt action]! Yes. I feel like if I feel really safe and if I feel like the story calls for it then I'm not so shy." (C) Cover Media