assisted in the film's visual effects. Digital Dimension worked on 200 visual effects shots in the film, including the sequence that shows characters John McClane and Matt Farrell crouching between two cars as another car lands on top of the other cars. To achieve this effect, a crane yanked the car and threw it in the air onto the two cars that were also being pulled by cables. The shot was completed when the two characters were integrated into the footage of the car stunt after the lighting was adjusted and CGI glass and debris were added. In the same sequence, John McClane destroys a helicopter that several of Gabriel's henchman are riding in by ramming it with a car. This was accomplished by first filming one take where one of Gabriel's henchman, Rand, jumps from the helicopter, and in the next take the car is propelled into the stationary helicopter as it is hoisted by wires. The final view of the shot overlays the two takes, with added CGI for the debris and moving rotor blades. The company also assisted in adding cars for traffic collisions and masses of people for evacuations from several government buildings. The Orphanage developed a multi-level freeway interchange for use in one of the film's final scenes by creating a digital environment and a long spiral ramp that was built in front of a bluescreen. When a F-35 jet is chasing McClane on the freeway, a miniature model and a full-size prop were both built to assist in digitally adding the jet into the scene. The nine-foot model was constructed from November 2006 through February 2007. When the jet is shown hovering near the freeway, editors used the software 3D graphics program Maya to blur the background and create a heat ripple effect. Filming and injuries Filming for Live Free or Die Hard started in downtown Baltimore, Maryland on September 23, 2006. Eight different sets were built on a large soundstage for filming many scenes throughout the film. When recording the sound for the semi trailer used in one of the film's final scenes, 18 microphones were used to record the engine, tires, and damage to the vehicle. Post-production for the film only took 16 weeks, when it was more common for similar films to use 26 weeks. In order to prevent possible injuries and be in peak condition for the film, Willis worked