"For the film it was necessary to not only create a recognizable Chicago of the future, but also have it destroyed and transformed into a primal jungle through four stages as the world changes to a different evolutionary timeline. Julian Caldow was tasked with the conceptual work on what the city of Chicago would look like in the future. Black Mountain Studio in Stuttgart, Germany, created futuristic buildings from scratch, which were then comped into the familiar landscape. A program developed for the telecommunications industry to assist in placing towers within Chicago had an extensive database that was tapped for building details. Real downloads from scans of the city generated an accurate three-dimensional city plan. This optimized the shooting schedule, allowing the filmmakers to know when and where to shoot and selectively adjust the camera for the real layout. Knowledge of the real widths of the actual streets helped in choreographing the bat chase sequence. The tarmac could be dressed to look like the road should at this point in the movie. Camera and car speed could also be tested in advance of shooting. Sebastian Greese and Michael Landgrebe worked as lead artists and Robert Kuczera modeled for Black Mountain."