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Show HN: I spent 6 years building a ridiculous wooden pixel display

benholmen.com

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Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#41

Post by munificent »

xpe wrote: post #17

You could order the presentation of a set of images by some distance metric :) - naively: Levenshtein - better: real world edit time based on a model of the display : probably dominated by XY travel distance

I was wondering about the algorithm to drive the plotter and update pixels, which ties into this.

Given the current image being shown and the next image, you (presumably) want to plot the pixels of the next image as quickly as possible. I believe the optimal algorithm is:

1. Calculate the set of pixels that are changed between the current and next image.

2. Find the shortest path from the plotter's current position through each of those pixels. I believe breadth-first search (O(n)) is sufficient here.

Running this on all potential upcoming images and choosing the one with the lowest total path cost would do what you propose under "better".

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#42

Post by saltcured »

I keep trying to imagine "faster" variations.

What about some system to shoot wooden spheres into a tube or channel for each scan line, selectively feeding different color spheres. Some combination of gravity or pneumatics to drive it. So a scan line would flush out one end and refill from the other. Then scale it up to a stadium size unit with bowling ball pixels.

I guess a challenging part would be proper timing to recycling the colors back into their appropriate supply channels. And also introducing some kind of damping to quiet it down and reduce the wear and tear on the pixels.

On the other extreme, you could go active matrix and have blocks that simply rotate in place to show different face colors based on some solenoid/servo action.

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#43

Post by skrebbel »

benholmen wrote: post #21
xpe wrote: post #17

You could order the presentation of a set of images by some distance metric :) - naively: Levenshtein - better: real world edit time based on a model of the display : probably dominated by XY travel distance

Oh I kinda love the idea of drawing the next one based on the pixel diff! Would be fun to game that queue.

you could have it render a movie

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#45

Post by jstanley »

Hah, cool, I had an idea for a similar project (although I'm not crazy enough to make 1000 pixels, or a robot to turn them for me). But I got as far as making a JavaScript simulation and realised I couldn't be bothered manually turning the beads https://incoherency.co.uk/beadboard/

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#46

Post by re »

Really cool! I just watched it finish "cat saying 'hi'". It doesn't look like any new posts have shown up on @kilopx.com on Bluesky for the last 9 days though.

A few suggestions for improvements:

- After completing a submission, move the "pen" out of the way as much as possible to get a clean photo of the completed art before moving onto the next submission.

- On the website, show attribution for the currently in-progress submission.

- On the website, have a "history" gallery for completed submissions. It looks like pending submissions have permalinks that say "Timelapse will be available after this is drawn", but there's no way to discover permalinks for completed submissions (or the in-progress one).

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#47

Post by rented_mule »

saltcured wrote: post #42

I keep trying to imagine "faster" variations. What about some system to shoot wooden spheres into a tube or channel for each scan line, selectively feeding different color spheres. Some combination of gravity or pneumatics to drive it. So a scan line would flush out one end and refill from the other. Then scale it up to a stadium size unit with bowling ball pixels. I guess a challenging part would be proper timing to…

Your idea is not too far from marble pixel art machines... https://youtu.be/w1ks0Vy98KI

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#48

Post by daotoad »

derefr wrote: post #28

Speaking of "alternatives to e-ink for a zero-power-use-when-not-updating dot-matrix display"... Has there ever been designed a "display" that is just a thermal printer hidden in one end of a box, and a take-up spool + tensioning spring hidden on the other end, such that the "display" is then a continuous thermal paper "scroll" stretched across the box behind [UV-protective!] glass, that can be "refreshed" by printin…

If you wanted to take this a little further, you could cover the "display" with heat erasable ink like is used in a Pilot Frixion pens.

This ink is interesting in that it fades when heated (60 C), but darkens when cooled (-10 C). In between those temperatures it is stable.

Thus you could have one loop that is continuously reused. Not sure how many cycles you can get before the ink degrades.

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#49

Post by rexreed »

This is cool. I wonder, as you were iterating on the design and development, why didn't you start with a very small grid (10x10) to validate or test different options for their practicality and operation before scaling up to the 1000 pixel versions? It might have saved a lot of time and money, but maybe small scale tests aren't sufficient to work out the kinks?

Re: Show HN: I spent 6 years building a ridiculous wooden pixel display

#50

Post by turtlebits »

derefr wrote: post #28

Speaking of "alternatives to e-ink for a zero-power-use-when-not-updating dot-matrix display"... Has there ever been designed a "display" that is just a thermal printer hidden in one end of a box, and a take-up spool + tensioning spring hidden on the other end, such that the "display" is then a continuous thermal paper "scroll" stretched across the box behind [UV-protective!] glass, that can be "refreshed" by printin…

Not sure if you can call it a display if you have to throw it away to change an image.
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