TL;DR
The science-fiction hologram, a picture floating in the air that a whole room can walk around, just got a homemade cousin. A builder known as AncientJames has made a display called Vortex: two LED panels mounted back to back spin so fast that, as they sweep through a volume of space, they draw an image with real depth that can be seen from any angle, no headset and no glasses. It runs on a Raspberry Pi 4, a $35-class hobby computer, sits inside a hand-trimmed plastic lighting globe, and its software, simulator and 3D-printable design files are public, so anyone with a printer and some patience can try to build one. That is how a lot of display technology spreads: first one clever build, then a hundred copies, then a product. To see our odds on when walk-around 3D images reach living rooms, and the timeline of breakthroughs that leads there, subscribe.
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