Sony Pictures Entertainment and director J Blakeson bring author Rick Yancey's popular novel series to the screen. Starring Chloë Grace Moretz and Liev Schreiber, the film follows Cassie Sullivan, a young woman struggling to survive the latest in the waves of alien invasion as she searches for her lost brother. The production required... [a] variety of high-end visual effects by Mammal Studios...
Mammal Studios contributed a wide shot of an avian flu quarantine area, set up in a football stadium in Cassie's Ohio hometown. "They had dressed this football field with medical tents and cots," said Mammal Studios visual effects supervisor Greg Liegey, "but they didn't have the coverage of extras activity and materials that they needed on location. They were a lot of big, empty spaces in the plates, and the scene didn't look as bustling and busy as hey wanted; and so, we filled in the empty, grassy areas with people, cots, tents and vehicles. Since this hadn't been planned as a visual effects shot, we had to do a camera track of the whole thing, and then insert all of our activity and additions into that moving plate."
To add people, Mammal Studios artists used alternate takes of the footage and projected them onto cards. "There might have been three people walking across an area," said Liegey, "but we had to make it look like 10 or 15 people. If this had been planned from the start, they might have decided to make a whole section of the quarantine area a CG replacement, and they would have kept that area free of people, to make that easier. In this case, we had to work with what was in the plate." Mammal Studios also added flocks of birds to the quarantine shots. "There were no birds in the original plates, and the director wanted to make sure that people understood that the birds continue to threaten the human beings, even as they are trying to save themselves. So we added birds that are swooping across frame or flying in circles. To make them look menacing, we animated them to do more vulture-type moves, rather than nicer flocking actions, swirling overhead as if they are looking for dead bodies to peck at."
You can read the entire article about the visual effects in 'The 5th Wave' in Cinefex #146