James BrownIncidentally, those models are from Cheello's voxel Doom: https://www.moddb.com/mods/doom-voxel-project/addons/voxel-doom - It's a lovely mod, and makes Doom feel more like my memories of playing it than the real thing does.
Latest flickery mess
I had a panel left over, and I thought I should have another stab at an oscillating display. I wanted to give it an undulating motion and came up with what seemed like a nice linkage, but the end result looks like it was designed by Trevithick.
It's a nice fluid motion on the panel, but overall it doesn't bring me joy.
There must be at least 6D here.
I rewired the back of the panel to tidy up all the loose flappy cables. It now manages 600 rpm, which is not too flickery.
In the continuing quest for higher rpm, I've moved the controller down below the screen and across the axis of rotation. It's a lot harder to get at if I need to rewire anything, but it does improve the balance.
It feels as though I'm endlessly rebuilding it, for diminishing improvements. But in the most recent rebuild I finally solved a mystery that has been bugging me. When the display had been running for a while, it would quite abruptly lose balance and start vibrating. After the last occurrence, it was never quite the same. On stripping it down I found this.
That's the mount for the slip ring. A cylinder carrying a couple of copper bands fits over the pillar, and an M4 bolt goes own the middle to hold it all together. It has very clearly become bent, and without any signs of cracking. Presumably, as it spins, it heats up enough to soften the PLA, and the spring loaded brushes push it out of alignment.
I've reprinted it in ABS; going to see how well that lasts.
I continue to fail to shoot footage of it that does it justice.
This feels like a good match of style and content.
I’m now suspicious of all the PLA parts. The little pit with the Pi in it is getting very warm.
kind of feels like it needs monsters?
I do like an ample window and natural light, but it makes it hard to see the leds. Hence this pirate astronaut.
Doom running at a larger scale. Easier to make out what's going on, harder to see what's shooting at you.
https://youtu.be/bRe1OSkeiQg
https://youtu.be/bRe1OSkeiQg
Voxel Doom
This display works by spinning a matrix display rapidly about a vertical axis, lighting up each LED as it passes through part of a 3D image. The way you update the displays has a big impact on the quality of the image.
In this gif, each dot represents a column of LEDs - we're looking at the device from above. Here the panel is treated like a 2D display which just happens to be moving. Each scan line is repeatedly visited in turn, sweeping out a set of slices where the image can be displayed.
In this gif, each dot represents a column of LEDs - we're looking at the device from above. Here the panel is treated like a 2D display which just happens to be moving. Each scan line is repeatedly visited in turn, sweeping out a set of slices where the image can be displayed.
If you turn the panels 90 degrees so their scan lines are now columns, you can do a bit better. The update doesn't have to be sequential - instead of stepping one column at a time, you can skip a few each time. As long as you pick a number which is coprime with the number of columns, and you wrap around once you go past the last one, you'll still visit each of them but spread out more evenly throughout the volume.
The real improvement comes when you adjust the update rate for each column to match the length of the track they have to sweep out. Instead of wrapping around when you reach the last column, you wrap around when your counter reaches the square of the number of columns, and you update the column corresponding to the integer square root of the counter. This gets rid of the bright dense region in the middle, and adds more updates out at the edges making them less sparse.
In practice it's complicated by the fact that these panels update two lines at once. Every time you update a column in the outer half, you're also updating one in the inner half. I couldn't find a simple procedural update strategy to spread these evenly, so I ended up generating a lookup table for it using simulated annealing.
First test of the new design, and already I’m happy. Quiet, high refresh rate, and doesn’t feel like it’s seconds away from embedding itself in my face.
Dynamic balancing using a tray of marbles and iPhone slowmo.
In motion https://youtu.be/na7pvihXhYs
So many complaints about the framerate on that last video, so I decided to upload one with a shorter exposure and more flicker. But I still ended up keeping it below 30 fps, so I suspect the complaints will be about both framerate and flicker. Just have to hope the algorithm doesn’t go so large on this one. https://youtu.be/gBfclb9hXCI
New dome!
There are many advantages to moving to smaller panels in the new design (momentum etc), but the price drop going to a 300mm dome from 400mm would be justification enough.
There are many advantages to moving to smaller panels in the new design (momentum etc), but the price drop going to a 300mm dome from 400mm would be justification enough.
There’s now an accelerometer in the base, synced to the rotation of the screen. I’m hoping this will help me get it balanced better. I don’t entirely understand the shape it’s producing, but the line is pointing in roughly the direction I think it should be pointing.
2D video of 3D projection of 4D object.
There’s a fair bit of planning involved in finding the true centre and height of these domes. When I come to make the cut it feels like cleaving the Cullinan diamond.
With the previous dome the cut had a somewhat hand made look to it, so I printed a thin piece of trim to slip over the edge and keep it neat. It was too big for the printer so I used TPU, printing it in a spiral and flexing it back in to the right diameter. An unexpected benefit was that it was way quieter with that isolating the dome from the base.
This time the cut went better, but I’m still going to give it a gasket for that reason.
This time the cut went better, but I’m still going to give it a gasket for that reason.
25 fps. That's an actual frame rate.
Now thinking I should have filmed the tool I made to press all the clips on this IEC socket so I could get it out of the housing in order to film the satisfying click it makes when it goes in.
Easier to see the 3D when it's only the camera that's moving.
Yet another round of finding new places to hang counterweights, and I’ve hit 900rpm - 30fps. Amazing to scroll back to the start of this thread and see me wonder if I could get some sort of rudimentary depth effect going.
https://www.youtube.com/watch?v=ydk3BhlUWYE I've been working more on capturing footage. Hand held camera movement is still a mess, but putting the content into rotisserie mode helps sell the 3D with a static camera.
Volumetric fish bowl
What this thing needed was another source of barely recognisable low res flickery points of light.
I built a contraption for my camera
Construction video for this display… https://youtu.be/pcAEqbYwixU
Vortex Assembly
I uploaded the 3D printable parts for it here. https://github.com/AncientJames/VortexParts - honestly don’t know if it’s at all useful without the specific parts I had (and the panels are just aliexpress roulette), but lots of people were asking.
I tried the thumbnail testing feature on Youtube for the first time, which was fun. Upload 3 different images, and it randomly applies them and shows you which one was the most engaging. This was the winner.
(I didn't include one with my surprised face and an overlaid arrow pointing at something)
Everyone needs to build one of these displays so I can spend my time writing games for it.
Amazing what these Arm processors can do.
Farbs@ancientjames OMG perfect choice of game for it.
Tom Forsyth@ancientjames Zarch3D! Astonishing.
Marco 🌳 Zocca@ancientjames very cool!!
Deathmaster Megalodon Ultrakill 9000@ancientjames glossing over the fact you own a homemade orb
Sophie@ancientjames Woah! Looks amazing!
Yiming Wu ✅ Use OurPaint@ancientjames the problem with rotary type displays is that you can't have anything in the middle 🤔 the reciprocating display type would handle it better bit I guess it would be louder
Mark Fraser@ancientjames Lander / Zarch
Alan Harding@ancientjames the Lander demo is one of the cornerstones from my childhood that got me into programming games so this image is hitting me right in the feels
Robee? Na! 🌈@ancientjames Zarch!!! 💜 The killer app
zl2tod@ancientjames
I reckon you would sell a run of 100 in no time, maybe 1000, perhaps more.
Perhaps a batch of 10 first for debugging.
The old vector graphics arcade game Tempest might translate well to your display.
subROV@ancientjames I was looking at building one in the local nerdspace when I saw you have a github, but stopped since there’s no software (no criticism, we all admire your work)
@subROV I’m going to put the software on github but I’m making an explanatory video to go with it.
@ancientjames thank you!! 🥺😭👏👏
faxmodem
Jason Coon@ancientjames shutupandtakemymoney.gif
David MankinsI once saw a 3D display that consisted of a cabinet with a speaker and vector monitor mounted overhead. There was a mirror in front of you that you treated as “the display” (the thing you looked at). The “speaker cone” was a sheet of reflective mylar, the speaker would vibrate it at 24-60 Hz, changing the focal depth of the virtual image, which reflected the contents of the monitor, timed to match the depth of the virtual image. That virtual image was what you saw in the mirror in front of you.
Ah, here we go: https://ui.adsabs.harvard.edu/abs/1988SPIE..902...10S/abstract
Spacegraph, A True 3-D Pc Peripheral
The SpaceGraph technology has been packaged as a table-top display station that is a peripheral device for an IBM PC/AT or compatible. It produces 3-D graphics by oscillating the virtual image of a CRT through space while synchronously writing on the screen. In the resulting display volume, one sees a self-luminous, high-contrast, sharp, model-like figure composed of points, lines, and alphanumerics. Optical means include a varifocal plate mirror and a specially designed, large-screen, directed-beam monitor. Electronic means include a controller on a card for an IBM PC/AT or compatible. Software running in the PC allows one to describe a 3-d picture in high-level terms. The controller card can display two pictures at once, and each is double-buffered. A run-time-writable brightness-lookup table takes advantage of 8-bit brightness tags on all 32k displayable points. The software interface is command-driven and includes general and command-specific help. It is capable of getting commands either from files, from the keyboard, or from a combination. Commands take intuitive forms, such as line (3,4,5) (1,2,6) or text (2,4,3) "abc" and locations in space may be given names for convenience of future reference. Additional features are autoscaling, a cursor, and saved display lists. Existing application software can most easily interface to SpaceGraph by writing out files of such commands. An example is the supplied interface to BBN's proprietary software product, RS/1.
hikaricai@lain_7 @ancientjames
I found the paper on "https://www.cs.unc.edu/~fuchs/publications/Design%20of%20and%20image%20editing82.pdf"
In fact, my ideal of floating 3d pov dispaly is similar, just rotating midair-mirror instead of vibrating mirror and led pannel instead of crt.
I found the paper on "https://www.cs.unc.edu/~fuchs/publications/Design%20of%20and%20image%20editing82.pdf"
In fact, my ideal of floating 3d pov dispaly is similar, just rotating midair-mirror instead of vibrating mirror and led pannel instead of crt.
@ancientjames Maybe someone can transplant nds or n64 emulator.
Jonathan@ancientjames I involuntarily made a surprised face when reading this - maybe a have a future as a content creator.
@jonbro The market for reacts videos is wide open at the moment. So many things going unreacted to.
Rob Norris@ancientjames I didn't start following this project until recently but it's been super inspiring for me and I really appreciate the effort you have put into sharing it with us. It's fantastic.
@tpolecat thank you!
@ancientjames haha, you've reached the uncanny valley now where I think you are showing me a 3d render of the product.
@jonbro There's definitely a sweet spot of realistically scrappy but not too shitty, which I keep missing
Graham Sutherland / Polynomial
Waltteri@ancientjames absolutely gorgeous work! 🧡
Matt Gray
Ivor Hewitt@ancientjames 👏 stunning. bravo!
Mx Autumn 
WOW
Wintermute_BBS
Jorin@ancientjames what the fuck
ShadSterling@ancientjames reminds me of the MCP
digitalfox@ancientjames Ooh, this all looks quite nice!
In the unlikely event you have an Xbox Kinect laying around, or a Pixel 4/Pixel 4 XL, I bet it would pair quite well as a realtime source for your display, e.g. https://research.google/blog/udepth-real-time-3d-depth-sensing-on-the-pixel-4/
jonny (good kind)@ancientjames
Holy shit it looks even better close up like that
Holy shit it looks even better close up like that
Thomas Sturm@jonny @ancientjames Agreed. This looks awesome. Showed it to our teenager and he wants to know where we can buy one. 😅
Francis 🏴☠️ Gulotta@ancientjames it’s really hard not to think you’re moving the camera around, that’s a bit uncanny
varx/tech@ancientjames Kinda want to see what happens if you feed it a live stream of itself. Figure there's a 90% chance the image just collapses into garbage, but it might be cool.
@varx I did try that! The depth camera isn't fooled for a second, and you just see snapshots of the panel at various angles inside the dome.
@ancientjames that looks amazing! It needed a perfect loop. 😁
merlin / alex glow
AxWax@alexglow @jasoncoon @ancientjames
Holy cow(fish)! 🤯 😻
@jasoncoon Thank you!
kira :3@jasoncoon @ancientjames this is amazing, it's sooo cool
Tobias@ancientjames You're amazing!
Stellar 🇫🇷 (
era)@ancientjames this is so cool 
good job
good job@ancientjames Do you think this could be done with an OLED screen? Too fragile?
@hjhja45yaejsgjmf a fast oled refreshes at a few hundred fps, this needs a few thousand. You could make it work, but it wouldn't have the same density of voxels.
dch82@ancientjames Try making a 3d version of the Crab Rave video