 Beebe's approach was to develop "a world under siege, but not a bleak, dark, post-apocalyptic landscape"; Beebe preferred to avoid the saturated bleach bypass look.Thirty-five-millimeter film was used instead of digital cameras to evoke the World War II footage that provided inspiration for the battle scenes.Production designer Oliver Scholl and his team worked with lead builder Pierre Bohanna to develop concept art for several battle suit options based on contemporary, real-world powered exoskeleton initiatives, such as those supported by DARPA.