The Virtual Production of Ready Player One ran through the Unity game engine software. It was the visual end-point for processes at each step - 3D displays across stage floor screens, scouting in VR, and even rendering each frame for the film's rough cut.

A game engine's real-time updating and displaying abilities bring immediacy to traditionally slow VFX workflows. Real-time means instant; there's no waiting, no delayed processing, everything updates together in context.

The actors wore optical tracking marker suits and head-cameras to capture their performances. These suits are lined with reflective marker balls which provide three-dimensional data when picked-up by 100's of infrared Vicon cameras surrounding the stage - enabling the position and orientation of actors to be continually tracked as they move.

This data streamed in real-time to MotionBuilder, which maps and scales (retargets) the data to virtual skeletons comprised of joints and bones of varying sizes. The animated skeletons then stream to Unity (also in real-time!) where they’re applied to avatars in the film's virtual environments. Here they are rendered live with lighting, shadows, and other filmic effects (depth of field, fog, particles) layered on top.

In a virtual shoot there's two parts to filming; actor capture and camera capture. Traditionally these are tethered, but in Virtual Production actor and camera performances can detach.

On the motion capture stage the director focuses on the actors, then later the camera is worked on separately, adjusting and improving the framing, perspective, cuts, paths, lens... Spielberg would do this for many hours each day in a private motion capture space, he said of the process "I had to learn how to make a film like this while I was making a film like this".