The makers of the upcoming superhero epic, Man of Steel, have released this new 13-minute behind-the-scenes look at the film, which comes out June 14. In the video, screenwriter David S. Goyer (who worked with Christopher Nolan on the Dark Knight trilogy) says the style of the Superman reboot was inspired by gritty realism and is a departure from Superman movies of the past. “Our approach was not a comic book Superman. It was just to do a more realistic Superman. A Superman that exists in the real world” …