RC3 2021: Now Here, Nowhere

The annual meeting of the Chaos Computer Club, Germany’s giant hacker group, is online again this year. While those of us here are sad that we don’t get to see our hacker friends in person, our loss is your gain — the whole thing is online for the entire world to enjoy.

This year’s Congress has gone entirely decentralized, with many local clubs hosting their own video streams and “stages”. Instead of four tracks, there are now six or seven tracks of talks going on simultaneously, so prepare to be overwhelmed by choice. You can find the overall schedule here, so if you see anything you’d like to watch, you’ll know when to tune in.

Like last year, there is also a parallel 2D simulation world, like Zelda with videoconferencing, but for which you’ll need a ticket, and they’re sold out. (Check out the demo video if you want to see what that’s about.) And what would a conference be without t-shirts, armbands, and even a sticker exchange? Or course, it all has to be done by mail, but you do what you can.

We’ll be keeping our eyes on the talks, and let you know if we see anything good. If you do the same, let us know in the comments!

Realtime Shadows On N64 Hardware

Although the Nintendo 64 console has in the minds of many been relegated to the era of ‘firmly obsolete graphics’, since its graphic processor’s (GPU’s) lineage traces directly to the best which SGI had to offer in the 1990s, it too supports a range of modern features, including dynamic shadows. In a simple demo, [lambertjamesd] demonstrates how this feature is used.

As can be seen in the demonstration video (linked after the break), this demo features a single dynamic light, which casts a shadow below the central object in the scene, with a monkey object floating around that casts its own shadow (rendered into an auxiliary frame buffer). This auxiliary buffer is then blended into the main buffer, as explained by [ItzWarty] over at /r/programming on Reddit.

This effectively means that the main scene uses a shadow volume, which was used extensively with Doom 3. The primary reasons for why the N64 didn’t use shadow volumes all over the place was due to the limitations this places on the shadow caster (objects) in the scene, such as the need to be convex, and overlap is likely to lead to artifacts and glitches.

Doom 3 would fix this with the use of a stencil buffer that would further refine the basic dynamic lighting support on the N64, which ultimately would lead to the fancy video game graphics we have today. And which no doubt will look properly obsolete in another decade again, as usual.

Continue reading “Realtime Shadows On N64 Hardware”

Seoul Introduces Self-Driving Taxis

Last year the Seoul city government passed an ordinance enabling the commercial operation of autonomous passenger-carrying vehicles. A six square kilometer region in the Seoul neighborhood of Sangam, near the 2002 World Cup Stadium, was designated as a pilot program test bed. This area encompasses 24 streets totaling 31.3 km. Two companies were selected, and the pilot program launched a few weeks ago. Currently there are three vehicles and passengers can ride for free during this introductory phase. Three more taxis and a bus will be added within this year, with plans for 50 in this region by 2026. For the time being, these cars require a standby driver who takes control in an emergency and in school zones. Check out the short news report (in English) below the break.

There was a smaller autonomous driving test program in the city of Sejong which we wrote about back in January, and [Alfred Jones] gave a keynote presentation at the 2020 Hackaday Remoticon on the challenges of designing self-driving vehicles if you want to learn more on this topic.

Continue reading “Seoul Introduces Self-Driving Taxis”

Mini Linear Actuators From DVD Drive Parts

For many years now a source for some of the smallest and cheapest home made CNC mechanisms has been the seemingly never-ending supply of surplus CD and DVD-ROM drives. The linear actuator that moves the laser may not be the longest or the strongest, but it’s free, and we’ve seen plenty of little X-Y tables using CD drives. It’s these mechanisms that [Nemo404] has taken a little further, freeing the lead screw and motor from the drive chassis and placing them in a 3D-printed enclosure for a complete linear actuator that can be used in other projects. (Video, embedded below.)

There seems to be no positional feedback, not even the limit switch that would grace a typical CD drive, but aside from that it makes for a compact unit. There are two versions, one for a linear bearing and the other for the brass bushes found in CD drives. It’s unclear how strong the result is, but it appears to be strong enough to demonstrate lifting a small container of screws.

Should you need to make your own actuator then aside from the easy-to-obtain old CD drive the files can be found on Thingiverse. And introduce yourself to the world of CD drives for CNC machines by taking a look at this mill.

Thanks [BaldPower] for the tip!

Continue reading “Mini Linear Actuators From DVD Drive Parts”

FlyBrainLab: Google Earth But For A Drosophila Fly’s Brain

In biology there are a couple of truly crucial model animals and insects. Not that they’re particularly good students, or pick up their own trash, but in the sense that they have become standard model organisms for research. Aside from genetic research, the FlyEM project seeks to fully map a little fly’s brain’s neural connections. This common fly, called drosophila melanogaster (or ‘lesser fruit fly’) has been the subject of a lot of genetic studies, but this study of its brain structure may provide insights in how our brain works as well.

Based on electron microscope images of thin slices of a drosophila brain, the three-dimensional structure of this tiny brain is reconstructed to not only determine the location of each neuron, but also their connections with other neurons. We know that about two-thirds of their brain is dedicated to processing the visual information from their relatively advanced compound eyes, but a lot is still unknown about how this is done, or how the brain’s structure develops.

If it’s always been your dream to tinker with a little fruit fly’s brain, you can do so yourself using the open source FlyBrainLab tool provided, along with the freely available data sources. This tool does not just allow one to visualize the drosophila brain in great detail, but also to create executable circuits and study their functionality. With neurobiology still a largely unexplored territory, this makes for an amazing tool to make this research accessible to anyone.

(Thanks for the tip, [Hernandi Krammes])

New Holographic Display Hacks The Light Field

[Petapixel] has an interesting post about a startup company’s new holographic display that claims to be “indistinguishable from reality.” The company behind it, Light Field Labs, claims their system requires no glasses and handles different angles.

You can see a bit in the [C|Net] video below, but — of course — being on YouTube, you can’t get a sense for how good the 3D effect is.

Continue reading “New Holographic Display Hacks The Light Field”

Is Cloud Seeding Good, Bad, Or Ugly?

The Chinese Communist Party celebrated its centenary on the 1st of July, 2021. For such a celebration, clear skies and clean air would be ideal. For the capable nation-state, however, one needn’t hope against the whims of the weather. One can simply control it instead!

A recent paper released by Tsinghua University indicated that China had used cloud seeding in order to help create nicer conditions for its 100-year celebration. Weather modification techniques have been the source of some controversy, so let’s explore how they work and precisely what it was that China pulled off.

Continue reading “Is Cloud Seeding Good, Bad, Or Ugly?”