It looks like [Michel David] and his team at volumetrics.co have really upped their game: the game being production of a 3D volumetric video display.
We’ve covered an earlier version of the same technique, and still the best technical explanation of what they’re up to is to be found at their old website. But it’s a simple enough idea, and we expect that all of the difficulty is in making the details work out. But if you look at their latest video (just below the jump), we think that you’ll agree that they’ve ironed out most of the wrinkles.
The newest version uses a standard overhead projector (“beamer” in “German”) to project images onto a rotating helix. By changing the image rapidly in sync with the rotor, you can choose how high up the corkscrew the light beam hits. Spin the rotor around (on a Dremel!) fast enough and your POV takes care of the rest. We really like the simplicity of the current setup, and the results speak for themselves.
Doing the math to figure out exactly where and when each point of light should be projected is no mean feat, but if you’ve got a very accurate model of the helix, it should be possible. And that makes this a perfect excuse for a big 3D printer — you can ideally make a helix model in your computer and then print out the exact same shape.
We’d like to see a lot more detail about the newer version, and maybe a link to some of the software. And we’ve still got one nagging question: how do they get the sync right between the spinning helix and the video display? We can’t see any rotation sensors or feedback. Is it just tuned?