Angelina Jolie is not one to shy away from a challenge and her latest directorial effort is no different.The Oscar-winning actress is currently in Australia directing the harrowing WWII biopic Unbroken.I's not an easy feat, according to the film's screenwriters Joel and Ethan Coen, who talked to The Independent's Radar magazine, out Saturday.Shooting the life story of World War II hero Louis Zamperini is so challenging because of all the war and water scenes.'That movie is really a motherf***er ... a difficult production thing,' one of the brothers told the paper.'There is aerial combat stuff, dogfight stuff, and there is stuff on a lifeboat on an open sea.'The Coens usually direct their own scripts - think Fargo and The Big Lebowski - but admit they are relieved they didn't have to step behind the camera on this one.'There is something good about being able to blithely write whatever you want without having to worry about having to think, even in the back of your mind, about the reality of production,' one of the two added.'But you know, it's from a book, it's not fiction stuff, so it's not like Angie can blame us for that.'Quizzed why they were hired to make a script of Laura Hillenbrand's book about the hero, they added: 'We know [Angelina] a little. Why did she solicit us? Yeah, because she knows us.' Last October, Angelina spoke to Entertainment Weekly about the difficulty of the shoot.'On set, we started to joke and say, "Tomorrow will be easier," knowing full well that on this challenging shoot, there are no easy days,' the fiancée of Brad Pitt told the publication via email.'Anytime it gets tough, we think of the real men who lived through this, and no one complains. In fact, we all just feel honored to be here.'Unbroken tells the true story of American Olympic runner Zamperini, who was taken prisoner by the Japanese army during World War II.The movie stars 'Skins' actor Jack O'Connell, Garrett Hedlund and 'About Time' star Domhnall Gleeson. It is scheduled for release in December this year.Angelina has been spotted Down Under with Brad and her six children since November.

source : Daily Mail