Redirected Walking In VR Done Via Exploit Of Eyeballs

[Anjul Patney] and [Qi Sun] demonstrated a fascinating new technique at NVIDIA’s GPU Technology Conference (GTC) for tricking a human into thinking a VR space is larger than it actually is. The way it works is this: when a person walks around in VR, they invariably make turns. During these turns, it’s possible to fool the person into thinking they have pivoted more or less than they have actually physically turned. With a way to manipulate perception of turns comes a way for software to gently manipulate a person’s perception of how large a virtual space is. Unlike other methods that rely on visual distortions, this method is undetectable by the viewer.

Saccadic movements

The software essentially exploits a quirk of how our eyes work. When a human’s eyes move around to look at different things, the eyeballs don’t physically glide smoothly from point to point. The eyes make frequent but unpredictable darting movements called saccades. There are a number of deeply interesting things about saccades, but the important one here is the fact that our eyes essentially go offline during saccadic movement. Our vision is perceived as a smooth and unbroken stream, but that’s a result of the brain stitching visual information into a cohesive whole, and filling in blanks without us being aware of it.

Part one of [Anjul] and [Qi]’s method is to manipulate perception of a virtual area relative to actual physical area by making a person’s pivots not a 1:1 match. In VR, it may appear one has turned more or less than one has in the real world, and in this way the software can guide the physical motion while making it appear in VR as though nothing is amiss. But by itself, this isn’t enough. To make the mismatches imperceptible, the system watches the eye for saccades and times its adjustments to occur only while they are underway. The brain ignores what happens during saccadic movement, stitches together the rest, and there you have it: a method to gently steer a human being in a way that a virtual space is larger than the physical area available.

Embedded below is a video demonstration and overview, which mentions other methods of manipulating perception of space in VR and how it avoids the pitfalls of other methods.

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Space Garbage Truck Takes Out The Trash

On April 2nd, 2018 a Falcon 9 rocketed skywards towards the International Space Station. The launch itself went off without a hitch, and the Dragon spacecraft delivered its payload of supplies and spare parts. But alongside the usual deliveries, CRS-14 brought a particularly interesting experiment to the International Space Station.

Developed by the University of Surrey, RemoveDEBRIS is a demonstration mission that aims to test a number of techniques for tackling the increasingly serious problem of “space junk”. Earth orbit is filled with old spacecraft and bits of various man-made hardware that have turned some areas of space into a literal minefield. While there have been plenty of ideas floated as to how to handle this growing issue, RemoveDEBRIS will be testing some of these methods under real-world conditions.

The RemoveDEBRIS spacecraft will do this by launching two CubeSats as test targets, which it will then (hopefully) eliminate in a practical demonstration of what’s known as Active Debris Removal (ADR) technology. If successful, these techniques could eventually become standard operating procedure on future missions.

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Moiré marine navigation light

Using Moiré Patterns To Guide Ships

Moiré screens for arrows
Moiré screens for arrows

[Tom Scott] ran across an interesting visual effect created with Moiré patterns and used for guiding ships but we’re sure it can be adapted for hacks somewhere. Without the aid of any motors or LED animation, the image changes as the user views it from different angles. When viewed straight on, the user sees vertical lines, but from the left they see a right-pointing arrow and from the right, they see a left-pointing arrow. It’s used with shipping to guide ships. For example, one use would be to guide them to the center point of a bridge. When the pilots see straight, vertical lines then they know where to steer the ship.

US patent 4,629,325, Leading mark indicator, explains how it works and how to make one. Two screens are separated from each other. The one in front is vertical but the one behind is split in two and angled. It’s this angle which creates the slants of the arrows when viewed from the left or right. We had to convince ourselves that we understood it correctly and a quick test with two combs showed that we did. See below for the test in action as well as for [Tom’s] video of the real-world shipping one.

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Upgrade Your Mac With A Touchscreen, For Only A Dollar

Imagine how hard it could be to add a touch screen to a Mac laptop. You’re thinking expensive and difficult, right? How could [Anish] and his friends possibly manage to upgrade their Mac with a touchscreen for only a dollar? That just doesn’t seem possible.

The trick, of course, is software. By mounting a small mirror over the machine’s webcam, using stiff card, hot glue, and a door hinge. By looking at the screen and deciding whether the image of a finger is touching its on-screen reflection, a remarkably simple touch screen can be created, and the promise of it only costing a dollar becomes a reality. We have to salute them for coming up with such an elegant solution.

They have a video which we’ve put below the break, showing a few simple applications for their interface. Certainly a lot less bother than a more traditional conversion.

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Is This The End For The C.H.I.P.?

There have been so many launches of very capable little single-board computers, that it is easy to forget an individual one among the crowd. You probably remember the C.H.I.P though, for its audacious claim back in 2015 to be the first $9 computer. It ran Linux, and included wireless connectivity, composite video output, and support for battery power. As is so often the case with ambitious startups, progress from the C.H.I.P’s creator Next Thing Co came in fits and starts.

In recent months there has been something of a silence, and now members of the community have discovered evidence that Next Thing CO are the subject of a Notice of General Assignment from Insolvency Services Group. This is followed up by the discovery that their office is available for rent.

A process called Assignment to the Benefit of Creditors is an alternative to bankruptcy proceedings yet still signals the end of a company as the service liquidates remaining assets. Despite the website and forum remaining online it appears that we may have seen the end of the C.H.I.P. and its stablemates. Hackaday has reached out to Next Thing Co for comment and will update this article if we hear back.

At the time it was launched, the C.H.I.P. was a pretty impressive product, and though it has since been eclipsed by products like the Raspberry Pi Zero, the board remains a useful item. The addition of the PocketCHIP all-in-one keyboard and display peripheral made it an instantly recognizable device, and it and its more powerful companion C.H.I.P. Pro module found their way into quite a few projects. For us the most impressive C.H.I.P. project is a retrocomputer, this miniature Apple II complete with monitor. If this really is the end for this particular little board, we’ll be sorry to see it go.

Thanks [smerrett79] for the tip.

Header image: Kiwamu Okabe [CC BY-SA 2.0].

What’s The Deal With Transparent Aluminum?

It looks like a tube made of glass but it’s actually aluminum. Well, aluminum with an asterisk beside it — this is not elemental aluminum but rather a material made using it.

We got onto the buzz about “transparent aluminum” as a result of a Tweet from whence the image above came. This Tweet was posted by [Jo Pitesky], a Science Systems Engineer at the Jet Propulsion Lab in Pasadena. [Jo] reported that at a recent JPL technology open house she had the chance to handle a tube of material that looks for all the world like a section of glass tubing, but was billed as transparent aluminum. [Jo] tweeted this because it was an interesting artifact that few people get to play with and she’s right, this is fascinating!

The the material itself is intriguing, and I immediately had practical questions like what is this stuff? What is it good for? How is it made? And is it really aluminum rendered transparent by some science fiction process?

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It Looks Like A Nintendo, But It’s Running A Pi: A Gamer’s Long-Sought Dream Handheld

[Christopher Foote] didn’t play quite as many games as he wanted to as a child. After years of catching up using the RetroPie and the PiGRRL 2, it was when he first picked up a Switch’s joy-cons that inspiration struck. Behold: the PiSwitch!

Realizing they operated on Bluetooth tech, [Foote] spent a fair chunk of time getting the joy-cons to properly pair to the Raspberry Pi 3 and function as one controller. Once done, he relied on Linux Joystick Mapper to manage the keybindings with some extra legwork besides to get the analog sticks working properly.

To make this console mobile, he’s packed a 6600mAh battery and Adafruit Powerboost 1000c into the device, added a second headphone jack and speaker for commuting and home enjoyment, and a Pi V2 camera module. A 3D printed case, encapsulating these components and a seven-inch touchscreen, also allows the joy-cons to be detached — though he plans on updating its design in the future.

The PiSwitch boots into a custom UI  that lets you select different services — RetroPie, Kodi, Debian, and the terminal — while the joy-cons seamlessly function together or individually regardless of the activity. Check out the quick intro tour for this project after the break!

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