The 35-year-old Titanic star said that it was never her intention to rely on her looks in Hollywood, and admitted that she actually prefers films that don't require her to look good.
She told Glamour, 'It's my chance to challenge myself to the fullest, which is one of the great joys about this job… I love it when a character requires me to look less than my red carpet best.
'It's more fun playing a character that requires you to look like dog s**t. I have just wanted to be an actress. That's always been my goal. I didn't want to be famous.
'I wanted to play incredibly challenging, multifaceted characters. Because we are all a puzzle.'