In I Am Legend, a virus hits in 2009, infecting everyone but Will Smith. By 2012, New York is rife with monsters at night yet empty during the day: a spookily beautiful dystopia. “Most apocalyptic movies are very dark, with burnt-out cities,” says director Francis Lawrence. “The truth is that if people left, nature would start reclaiming the city pretty quickly.” Creating the illusion of a verdant, depopulated Manhattan took $40 million of the film’s $150 million budget. And even with hundreds of assistants pushing pedestrians out of the frame, a visual-effects team still had to digitally remove each sign of life from shots, erasing people and darkening windows. Here’s how they constructed the opening scene, in which Smith hunts a deer in Times Square: Lasers mapped real buildings to within an inch, creating gray structures (1). Then the crew took thousands of digital photos, using them to add detail, while animators put in 3-D objects (2) that would eventually look like cars and billboards. The street itself, covered in grass, was practically the only thing built on a soundstage. The final result is what you see in (3). As for the TKTS booth (4), a hybrid of set design and CGI, it was based on plans for the unfinished renovation. And those billboards? “We had to decide which Broadway shows would still be open in 2009,” says visual-effects supervisor Janek Sirrs. And which Warner Bros. movies. “We’ve got an ad for Superman vs. Batman in there somewhere.”