[Groxx]

Tilt Five is a pretty impressive demo of how good (and cheap!) retroreflection can be, but tbh I think the format is just kinda unusable outside of demonstrations. It'll always be a "small" surface, or it'll take up way too much room that you can't use for literally anything else, as you risk damaging the surface. And when it's big, you lose a ton of usable space because you're seeing the far stuff at a sharp angle, so you can't render "big" things over there.

Maybe a roll-down giant screen like for a projector display would work better, to give you a big virtual "hole" in a wall, but I've only seen it on those smallish tables. Possibly due to projection power/angle limits?