a kinetic bar framework mounted on a wooden base made of 3d printed bars of alternative black and grey color, each joined with m3 bolts and nuts

Kinetic Cyclic Scissors

October 26, 2022 by Abe Connelly 6 Comments

[Henry Segerman] and [Kyle VanDeventer] merge math and mechanics to create a kinetic cyclic scissors sculpture out of 3D printed bars adjoined together with M3 bolts and nuts.

The kinetic sculpture can be thought of as a part of an infinite tiling of self similar quadrilaterals in the plane. The tiling of the plane by these self similar quadrilaterals can be realized as a framework by joining the diagonal points of each quadrilateral with bars. The basic question [Henry] and [Kyle] wanted to answer was under what conditions can the realized bar framework of a subsection of the tiling be made to move. Surprisingly, when the quadrilateral is a parallelogram, like in a scissor lift, or “cyclic”, when the endpoints lie on a circle, the bar framework can move. Tweaking the ratios of the middle lengths in a cyclic configuration leads to different types of rotational symmetry that can be achieved as the structure folds in on itself.

[Henry] and [Kyle] go into more detail in their Bridges Conference paper, with derivations and further discussions about the symmetry induced by adjusting the constraints. The details are light on the actual kinetic sculpture featured in the video but the bar framework was chosen to have a mirror type of symmetry with a motor attached to one of the central, lower bars to drive the movement of the sculpture.

The bar framework is available for download for anyone wanting to 3D print or laser cut their own. Bar frameworks are useful ideas and we’ve seen them used in art sculptures to strandbeests, so it’s great to see further explorations in this space.

Video after the break!

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How The Image-Generating AI Of Stable Diffusion Works

October 24, 2022 by Donald Papp 40 Comments

[Jay Alammar] has put up an illustrated guide to how Stable Diffusion works, and the principles in it are perfectly applicable to understanding how similar systems like OpenAI’s Dall-E or Google’s Imagen work under the hood as well. These systems are probably best known for their amazing ability to turn text prompts (e.g. “paradise cosmic beach”) into a matching image. Sometimes. Well, usually, anyway.

‘System’ is an apt term, because Stable Diffusion (and similar systems) are actually made up of many separate components working together to make the magic happen. [Jay]’s illustrated guide really shines here, because it starts at a very high level with only three components (each with their own neural network) and drills down as needed to explain what’s going on at a deeper level, and how it fits into the whole.

Spot any similar shapes and contours between the image and the noise that preceded it? That’s because the image is a result of removing noise from a random visual mess, not building it up from scratch like a human artist would do.

It may surprise some to discover that the image creation part doesn’t work the way a human does. That is to say, it doesn’t begin with a blank canvas and build an image bit by bit from the ground up. It begins with a seed: a bunch of random noise. Noise gets subtracted in a series of steps that leave the result looking less like noise and more like an aesthetically pleasing and (ideally) coherent image. Combine that with the ability to guide noise removal in a way that favors conforming to a text prompt, and one has the bones of a text-to-image generator. There’s a lot more to it of course, and [Jay] goes into considerable detail for those who are interested.

If you’re unfamiliar with Stable Diffusion or art-creating AI in general, it’s one of those fields that is changing so fast that it sometimes feels impossible to keep up. Luckily, our own Matthew Carlson explains all about what it is, and why it matters.

Stable Diffusion can be run locally. There is a fantastic open-source web UI, so there’s no better time to get up to speed and start experimenting!

In A Way, 3D Scanning Is Over A Century Old

October 2, 2022 by Donald Papp 23 Comments

In France during the mid-to-late 1800s, one could go into François Willème’s studio, sit for a photo session consisting of 24 cameras arranged in a circle around the subject, and in a matter of days obtain a photosculpture. A photosculpture was essentially a sculpture representing, with a high degree of exactitude, the photographed subject. The kicker was that it was both much faster and far cheaper than traditional sculpting, and the process was remarkably similar in principle to 3D scanning. Not bad for well over a century ago.

This article takes a look at François’ method for using the technology and materials of the time to create 3D reproductions of photographed subjects. The article draws a connection between photosculpture and 3D printing, but we think the commonality with 3D scanning is much clearer.

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Rib Cage Lamp Kicks It Up A Notch With Party Mode

October 1, 2022 by Donald Papp 8 Comments

We think [Michelle]’s sound-reactive rib cage lamp turned out great, and the photos and details around how it was made are equally fantastic. The lamp is made of carved and waxed wood, and inside is a bundle of LED lighting capable of a variety of different color palettes and patterns, including the ability to react to sound. Every rib cage should have a party mode, after all.

The LED strip is fashioned into an atom-like structure.

Turns out that designing good rib cage pieces is a bigger challenge than one might think. [Michelle]’s method was to use an anatomical 3D model as reference, tracing each piece so that it could be cut from a flat sheet of wood.

The resulting flat pieces then get assembled into a stack, with each rib pointed downward at a roughly 20 degree angle. This process is a neat hack in itself: instead of drilling holes all at exactly the same angle, [Michelle] simply made the holes twice the diameter of the steel rod they stack on. The result? The pieces angle downward on their own.

The LED lighting is itself a nice piece of work. The basic structure comes from soldered solid-core wire. The RGB LED strip gets wound around that, then reinforced with garden wire. The result is an atomic-looking structure that sits inside the rib cage. An ESP32 development board drives everything with the FastLED library.

Code for everything, including the sound-reactive worky bits, which rely on an INMP441 I²C microphone module is all available on GitHub. And if you want to make your own sound-reactive art, make sure to check out these arms as well.

Want to see the rib cage in action? A short demo video is embedded below that demonstrates the sound reactivity. Equally applicable to either party or relaxation modes, we think.

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AI Dreaming Of Time Travel

September 28, 2022 by Matthew Carlson 20 Comments

We love the intersection between art and technology, and a video made by an AI (Stable Diffusion) imagining a journey through time (Nitter) is a lovely example. The project is relatively straightforward, but as with most art projects, there were endless hours of [Xander Steenbrugge] tweaking and playing with different parts of the process until it was just how he liked it. He mentions trying thousands of different prompts and seeds — an example of one of the prompts is “a small tribal village with huts.” In the video, each prompt got 72 frames, slowly increasing in strength and then decreasing as the following prompt came along.

There are other AI videos on YouTube, often putting the lyrics of a song into AI-generated form. But if you’ve worked with AI systems, you’ll notice that the background stays remarkably stable in [Xander]’s video as it goes through dozens of feedback loops. This is difficult to do as you want to change the image’s content without changing the look. So he had to write a decent amount of code to try and maintain visual temporal cohesion over time. Hopefully, we’ll see an open-source version of some of his improvements, as he mentioned on Twitter.

In the meantime, we get to sit back and enjoy something beautiful. If you still aren’t convinced that Stable Diffusion isn’t a big deal, perhaps we can do a little more to persuade your viewpoint.

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laser cut acrylic coaster with rgb leds inside

Your Mug Will Like This Glowy Coaster

September 28, 2022 by Abe Connelly 2 Comments

[Charlyn] wanted to highlight their friends beautiful mug collection, so the Glowy Coaster was born.

The coaster is made up of six layers of laser cut acrylic. The top and bottom layer are cut out of clear acrylic, providing a flat surface for the coaster. A top pattern layer made of pearl acrylic has a thin piece of vellum put underneath it to provide diffusion for the LED strip sandwiched inside. The middle layers are made of peach acrylic and have their centers hollowed out to provide room for the electronics inside. The top pearl acrylic layer gives the coaster, as [Charlyn] writes, a “subtle touch of elegance”. The coaster itself is screwed together by an M3 screw at each point of the hexagon that feed through to heat-set inserts.

The electronics consist of a short NeoPixel strip, cut to include 12 LEDs pointed in towards the center of the coaster. The LEDs are driven by a Trinket M0 microcontroller with a LiPo “backpack” to provide power, attachment points for the exposed power switch and recharging capability to the 110 mAh 3.7 V battery. The code is a slightly modified NeoPixel “rainbow” wheel loop (source available as a gist). The design files are available through Thingiverse.

Creations like these highlight how much care and work goes into a project with minimal beauty, where decisions, like the opacity and thickness of the acrylic or countersinking the M3 screws, can have huge consequences for the overall aesthetic. [Charlyn] has an attention to detail that brings an extra touch of professionalism and polish to the project.

Coasters are a favorite for laser cutting and we’ve covered many different types, including
coaster bots, coaster engravers and even a color changing, drink sensing coasters.

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CMOS Oscillator Circuit Gets An Eatable Input

September 24, 2022 by Lee Wilkins 9 Comments

In interaction designer [Leonardo Amico]’s work Processing Decay, lettuce is used as an input to produce sound as an element within a CMOS circuit.

We’ve all seen lemons and potatoes doubling in science-fairs as edible batteries, but lettuce is something else. [Leandro]’s circuit uses alligator clips to insert lettuce into oscillators in this audio generating circuit — we think they’re behaving like resistors. Without refrigeration, the resistance of the lettuce changes, and so does the oscillation in the circuit. In a matter of hours, days, and weeks the cells degrades slowly, modulating the system and its sonic output. What a way to make music!

This hack isn’t the freshest — the video dates from nine years ago — but this is the first lettuce circuit we’ve seen. Of course, we love other food hacks like these multi-wavelength lasers used to cook 3D-printed chicken, or maybe the circuit can make use of this neural net detecting fruit ripeness.