Pacific Rim Uprising may not have lived up to its predecessor, but it’s still a fun movie about giant monsters fighting giant robots that, sorry to break it to you, weren’t actually so giant before the film’s visual effects artists worked their magic.

VFX studio DNEG shared this behind-the-scenes look at its work on Pacific Rim: Uprising, including some fun, raw footage of motion capture artists (mo-cap) performing the robot-on-robot fight scenes that would eventually flatten sprawling computer-generated cities. But on stage, they just banged into giant yellow pillows and padded walls.

Mo-cap has become a vital tool in the visual effects industry, not only because it’s a faster way to animate a character, but the results are far more lifelike than trying to recreate the movements of a human—or a humanoid Jaeger—using traditional frame-by-frame animation techniques. In this case, the captured motions were slowed down to make the Jaegers’ movements feel more appropriate for a 300-foot tall mech. You know, for science.