A new video explains the process.
For some of the memories visualized in Reminiscence, the production team realized these as moving pieces of footage that the actors could ‘walk around’ on set. In this new video from Warner Bros, visual effects supervisor Bruce Jones explains how the memories were projected on set.
The team used a Halo Gauze projection screen with thin mesh stretched in a cylinder shape and three 20K projectors mapped onto that screen in the shape of a half cylinder, and utilized three 20K projectors mapped on the circular screen. The move happened in real-time thanks to on-set tracking and there was also a visual effects component for the projections care of Scanline VFX.
Check out the video below.