Shooting a movie like “Moonfall” was a difficult process because the CGI effects were generated simultaneously with the physical shoots on set, so every detail had to be carefully planned in advance. As Roland Emmerich explained to Voice VFX, the preparation was quite long since the film contained 1,700 visual effects shots. To achieve so many of the computer-animated moments for the film, visual effects supervisor Peter Travers worked closely with a few Montreal companies, such as Scanline VFX, DNEG, Framestore, and Pixomondo.
To complement the CGI, the crew also built huge sets. The largest was a 45-foot-tall platform with two tanks holding 3,200 gallons of water. Once turned on, the massive machine created a wall of water to flood a hotel lobby.
While the impressive construction produced great practical effects, the conditions while filming these actual scenes were quite uncomfortable, according to John Bradley. The actor said Gizmodo that he came to set thinking that Roland Emmerich had found a way to visualize all the water needed for the scene through CG. But Bradley got a surprise instead, saying, “So I got [to the set], and it was just gallons and gallons of water squirting down a huge ramp right into my face, over and over again. I swallowed an ungodly amount.”