holy hell is this guy productive. it is worth scrolling through the various one-off projects he has completed and documented: https://mitxela.com/projects
I feel like a bit of an incompetent after looking through all that.
Tiny volumetric display
71–80 of 180 posts
Re: Tiny volumetric display
#72This is a really neat little project. Make sure to check out the other ones, some of which have been featured on HN before:
https://mitxela.com/projects/hardware
Personal favorite: the MIDI slide whistle.
Re: Tiny volumetric display
#73That's so cool! It would be interesting to see how it would perform in a vacuum. I wonder how big you could feasibly make it with vacuum containment.
Size is mostly about balance and engineering, if you cast the whole thing in resin you can spin it as fast as you want (or until the resin breaks apart).
Re: Tiny volumetric display
#74The centering issue could be solved by putting two led boards on top, back to back.Perhaps one board could shift the leds over by half to create an interlacing effect while doubling resolution.
There's gotta be some way to replace the rack-of-leds-spinner with something lighter. Mirrors? Acrylic light pipe matrix?
Why do you think the weight is the problem?
Re: Tiny volumetric display
#75That's beautiful. Nothing intelligent to add, just a very neat, clever and aesthetic project.
Re: Tiny volumetric display
#76Earlier quoted context omitted.
Free time is an excuse for most people - I'm not calling you out because I don't know you but most people spend a lot of time on YouTube - Hn - Watching TV etc and they could be working on a cool project instead.
Watching TV? YouTube? Sounds like your peer group is biasing you. How about struggling to work from home for 8 hours a day with two kids with zero familial support, an endless array of bills, and every possible life obstacle coming your way 24/7?
I wasn't calling you out. I don't know you. (look what I wrote) - best of luck in your situation!
Re: Tiny volumetric display
#77The centering issue could be solved by putting two led boards on top, back to back.Perhaps one board could shift the leds over by half to create an interlacing effect while doubling resolution.
Or just ... don't center, and change the math to acknowledge that the LEDs aren't centered?
There's another similar thing needing correction, which is that the LEDs near the center sweep a much smaller volume than the ones at the edge, and should be dimmed in order to yield equivalent luminance. LEDs describing tiny circles very close to the center would need to be dimmed a lot since they'd essentially be stationary. Wouldn't it be better then to sweep slightly larger circles at the middle anyways?
Re: Tiny volumetric display
#78Earlier quoted context omitted.
Yeah, well, that's not going to work. Interesting problem all the same. For a 1 meter diameter and height cylinder at 60Hz voxel refresh and say 1mm resolution at the edge one would need the plane rotating at obviously 3600 rpm, and edge pixels switching at about 380KHz. Since rgb is nice to have that's 10 gigabit for a somewhat coarse display. Nothing impossible, but not a DIY territory yet. I think one'd want the L…
I wonder if anyone has built multi-speed “layered” swept volumetric displays. For the center part, you would still just have one screen, but as you go further out, you’d have “spokes”, so that each screen only has to sweep a small angle (and roughly constant distance) during a frame, so that it rotates at lower RPM, and has to update fewer times. You would still need a bare minimum of 1-2 kHz, and a lot of screens, a…
Not exactly sure what the details, but there high quality, commercial products that are probably doing something like this: https://voxon.co/products/
Re: Tiny volumetric display
#79Creative. I probably have the persistence and interest to pull something like this off, but I lack the fantasy to come up with such cool projects. Luckily there's the internet to see what impressive stuff people come up with.
I have the reverse issue, I am constantly coming up with creative ideas, so that by the time I am done building idea A prototype v1 (something like what you see in this video) or v2, idea B comes along and distracts me from seeing idea A all the way through. And when the persistence and discipline is there, bills need to be paid, and the distraction is not idea B, but merely some mundane work.
Re: Tiny volumetric display
#80Many years ago, someone did a similar holographic hack with a spinning hard drive motor, a piece of reflective plexiglass mounted upright on it, and a small projector. As the plexiglass carved out a cylinder, the projector sent a series of frames adjusted for each little slice of 3D space. [0]
This gave me a wild idea: what if you could encode a low-resolution 3D video on the left channel of a stereo vinyl groove? [1] A special record player with a spinning plexiglass plate could then play holographic albums. The hologram would stay perfectly in sync with the music if you changed speeds or did turntable scratching.
[0] If anyone can find a link to the original spinning hard drive hologram project please drop it!
[1] I assume this wild idea isn't feasible given vinyl data rates?