Vanessa Hudgens didn't recognise herself in 'The Frozen Ground'.

The actress plays prostitute Cindy Paulson in the thriller - based on the true story of serial killer Robert Hansen - and had to work hard to get herself in the right frame of mind for the role.

She told the UK's BBC Radio 1: ''There were so many different crazy situations I had to put myself in.

''But honestly a good stare into the mirror, would do me some justice because I didn't look like myself at all. Just remind myself who I was playing and just making it real.''

The 24-year-old 'Spring Breakers' star also said while she loved acting in the thriller, she can't cope with horror films.

She added: ''I cannot watch scary movies. I can't do it. 'Frozen Ground' is good because it's like a thriller. It gets into your head. But ghosts and things that just pop up and scream at you, I can't do.''

Vanessa also said she admitted she found the process scary despite about the film as an actress.

She explained: ''Because it's based on a true story, these events actually happened. My character is based on a real person.

''So there is definitely a weight that comes along with that. We shot in some of the real places that the events took place in. So there is an energy that resonates and it's kind of heavy.

''It's fun. I love playing different characters. My cast was amazing. Nic Cage was incredible. John Cusack's terrifying. It's good stuff.''