Similar to OLD BRICKS, a regular HD projector and a depth sensor was used. But this program tracks the head position instead of hand position. More details in TECH.INFO.
A photo I snapped when I once stopped by a small shopping area just outside Echigo-Yuzawa Station (越後湯沢駅) in Japan.
To see the graphics more clearly, below is the video directly dump from computer screen (after converting the size from 1080p to 720p) while the program is running.
All videos here have no sound or music background, which I think is better this way.