Actress Vanessa Hudgens attends the YouTube Music Awards in New York CREDIT: REUTERS

Vanessa Hudgens recently sported a haircut so drastic a lot of people did not recognize her at first glance. The haircut was done as part of her role in the movie "Gimme Shelter."

In the film, the High School Musical star plays Apple, a teenager kicked out by her mother from their house after getting pregnant and then finds help at a suburban shelter.

Rosario Dawson and Brendan Fraser joins the cast as Apple's estranged parents, while Ron Krauss directs the movie.

In the first few days of the film's production, Vanessa posted on her Facebook page about the challenging role she is about to take, describing it as "crazy sauce."

"I'm so excited and proud of the work I've been doing and let me tell you, you all are going to be SHOCKED with how I look in this movie," Vanessa says in her post.

She also talks to Access Hollywood about how she cut her hair in preparation for the movie.

"I grabbed the scissors and started cutting my actual hair," Vanessa says. "Then my director decided that he was going to grab the scissors, and he grabs a chunk of my hair and just chops it."

In addition to the drastic haircut, Vanessa gained 15 pounds for the role, which was not hard for her to do as she is a self-described "foodie." But getting it off after the movie is an entirely different story.

"It was a lot of exercise... Just doing a lot of cardio, a lot of yoga and just really anything active."

About the role itself, Vanessa admits that every day in the filming of the movie was "definitely a challenge but one I embraced with open arms."

"It was just so thrilling top be able to push myself every day and see how far I could take it," she tells E! Online.

Vanessa cites the movie's birthing scene as the "most physical and emotionally draining scene," and that she ended up "popping blood vessels in [her] face."

She also developed a bond with her "baby" in the movie, so much that she "just had so much love for her but afterwards they call 'cut' and take the baby away and I'm just left there hanging."

"Gimme Shelter" will be out in theaters Jan. 24, 2013.