Printing Photorealistic Images On 3D Objects

May 13, 2015 by Theodora Fabio 36 Comments

Hydrographic Printing is a technique of transferring colored inks on a film to the surface of an object. The film is placed on water and activated with a chemical that allows it to adhere to an object being physically pushed onto it. Researchers at Zhejiang University and Columbia University have taken hydrographic printing to the next level (pdf link). In a technical paper to be presented at ACM SIGGRAPH 2015 in August, they explain how they developed a computational method to create complex patterns that are precisely aligned to the object.

Typically, repetitive patterns are used because the object stretches the adhesive film; anything complex would distort during this subjective process. It’s commonly used to decorate car parts, especially rims and grills. If you’ve ever seen a carbon-fiber pattern without the actual fiber, it’s probably been applied with hydrographic printing.

The physical setup for this hack is fairly simple: a vat of water, a linear motor attached to a gripper, and a Kinect. The object is attached to the gripper. The Kinect measures its location and orientation. This data is applied to a 3D-scan of the object along with the desired texture map to be printed onto it. A program creates a virtual simulation of the printing process, outputting a specific pattern onto the film that accounts for the warping inherent to the process. The pattern is then printed onto the film using an ordinary inkjet printer.

The tiger mask is our personal favorite, along with the leopard cat. They illustrate just how complex the surface patterns can get using single or multiple immersions, respectively. This system also accounts for objects of a variety of shapes and sizes, though the researchers admit there is a physical limit to how concave the parts of an object can be. Colors will fade or the film will split if stretched too thin. Texture mapping can now be physically realized in a simple yet effective way, with amazing results.

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Racing The Beam With Super Hexagon

May 13, 2015 by Brian Benchoff 24 Comments

Early game consoles like the Atari 2600 had a very, very limited amount of RAM. There wasn’t even enough RAM for all the pixels on the screen; instead, pixels were generated by the CPU as they were being drawn. It’s playing with scanlines and colorbusts with code, something we’re now calling. ‘racing the beam’ for some reason.

[Sam] is in the middle of an EE degree right now, and for a digital design class he needed to write some Verilog. At the time he was addicted to the game Super Hexagon, and the game mechanics are simple enough for an FPGA. He built his own implementation, but not one with framebuffers. He’s using a pipelined approach where each pixel’s value is calculated just a few clock cycles before it’s displayed. It vastly reduces the memory requirements, on his Altera DE1 board compared to the framebuffer approach.

Video below.

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Hackaday Prize Entry: A Pic32 Game Console

May 12, 2015 by Brian Benchoff 5 Comments

The official theme of the 2015 Hackaday Prize is to build something that matters. Solving the challenges facing the world is hard, and retro video games, despite what you read on Hackaday, do not matter.

That doesn’t mean there’s not space for the weird, esoteric builds out there; we have a best product prize that will dump $100k, a six month residency in the Hackaday Design Lab, and contacts with a lot of engineers with expertise in manufacturing. [Alex]’s extremely ow cost game console on a Pic32 is exactly what this prize category is looking for.

[Alex]’s project – XORYA – is based on the Pic32MX170F256, a chip that runs up to 50MHz, has 256kB of flash, and a full 64k of RAM. This is far beyond what the guys at Atari imagined back in the 70s, allowing the XORYA to have some amazing graphics.

Right now most of the build is dedicated to fleshing out the video system, and [Alex] has a great demo: rendering the Mandelbrot set in real time in 16 colors on an NTSC display with a resolution of 160×100. That’s a single-chip game console that’s right up there with the Uzebox, and a great example of the potential of the best product category for this year’s Hackaday Prize.

The 2015 Hackaday Prize is sponsored by:

Super Simple Cat Feeder

May 12, 2015 by Anool Mahidharia 24 Comments

Sometimes, along comes a hack that is just that. A kludged collection of parts thrown together quickly to solve some problem. [mightysinetheta]’s Upcycled Cat Feeder is just that – no pretensions.

It’s a cat feeder built out of a drill, wall switch and mechanical clock timer for under $10. Pretty much the simplest electric cat feeder you can make. Survives power outages just fine, is single serving, but due to the noise and motion it makes, it is a perfect Pavlovian trainer for the cat. The best way to describe it is as a Rube Goldberg machine.

Set the timer for the planned feed time (up to 12 hours in advance). At the appointed time, the timer triggers, the drill rotates, the old, broken screwdriver chucked in the drill turns. The cord tied to the screwdriver winds up like a winch. This pulls up the lid covering the cat’s dinner plate. The noisy drill announces it’s dinner time. When fully raised, the lid pushes up a short piece of PCV pipe. This flips a switch, that shuts off the drill. If you need build instructions, fear not. [mightysinetheta] has detailed build instructions although the pictures are probably all you’ll need.

Check the video after the break.

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Inside The Amazon Dash Button

May 12, 2015 by Brian Benchoff 155 Comments

The Amazon Dash Button is a tiny WiFi-enabled device that’s a simple button with a logo on the front. If you get the Tide-branded version, simply press the button and a bottle of laundry detergent will show up at your door in a few days. Get the Huggies-branded version, and a box of diapers will show up. Get the sugar-free Haribo gummi bear-branded version, and horrible evil will be at your doorstep shortly.

[Matt] picked up one of these Dash Buttons for 99 cents, and since a button completely dedicated to buying detergent wasn’t a priority, he decided to tear it apart.

The FCC ID reveals the Amazon Dash Button is a WiFi device, despite rumors of it having a Bluetooth radio. It’s powered by a single AA battery, and [Matt] posted pictures of the entire board.

Since this piece of Amazon electronics is being sold for 99 cents, whatever WiFi radio chip is inside the Dash Button could be used for some very interesting applications. If you have an idea of what chips are being used in [Matt]’s pictures, leave a note in the comments.

Retrotechtacular: Gone Fission

May 12, 2015 by Kristina Panos 18 Comments

This week’s film begins as abruptly as the Atomic Age itself, though it wasn’t produced by General Electric until 1952. No time is wasted in getting to the point of the thing, which is to explain the frightening force of nuclear physics clearly and simply through friendly animations.

[Dr. Atom] from the Bohr Modeling Agency describes what’s going on in his head—the elementary physics of protons, neutrons, and electrons. He explains that atoms can be categorized into families, with uranium weighing in as the heaviest element at the time. While most atoms are stable, some, like radium, are radioactive. This evidently means it stays up all night doing the Charleston and throwing off neutrons and protons in the process of jumping between atomic families. [Dr. Atom] calls this behavior natural transmutation.

Artificial transmutation became a thing in the 1930s after scientists converted nitrogen into oxygen. After a couple of celebratory beers, they decided to fire a neutron at a uranium nucleus just to see what happened. The result is known as nuclear fission. This experiment revealed more about the binding force present in nuclei and the chain reaction of atomic explosions that takes place. It seemed only natural to weaponize this technology. But under the right conditions, a reactor pile made from graphite blocks interspersed with U-235 and -238 rods is a powerful and effective source of energy. Furthermore, radioactive isotopes have advanced the fields of agriculture, industry, medicine, and biochemistry.

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Xilinx Borrows Code For Their Own Devices

May 12, 2015 by Brian Benchoff 55 Comments

Back in 2012, [tmbinc] discovered a neat little undocumented feature in the Xilinx ISE: the ability to use TCP/IP instead of JTAG cables. [tmbinc] was working on an Open Hardware USB analyzer and discovered the nearly undocumented Xilinx Virtual Cable, a single ‘shift’ command that opens up a TCP connection and sends JTAG data out to another computer on the network. It’s extraordinarily useful, [tmbinc] wrote a daemon for this tool, and everything was right with the world.

Yesterday, [tmbinc] discovered the Xilinx Virtual Cable again, this time in one of Xilinx’s Github repos. The code was extraordinarily familiar, and looking closer at a few of the revisions, he saw it was very similar to code he had written three years ago.

The offending revision in the Xilinx repo is nearly identical to [tmbinc]’s Xilinx Virtual Cable Driver daemon. Variable names are the same, the variables are declared in the same order, and apart from whitespace, code conventions are the same. This is not to say someone at Xilinx stole code from [tmbinc], but if this were a computer science lab, there would be an academic disciplinary hearing. What’s worse, Xilinx plastered their copyright notice at the top of the code.

In an issue [tmbinc] raised, he said he was flattered, but clarified that his code was developed entirely from scratch. He believes the Xilinx code was derived from his own code written three years ago. Since [tmbinc]’s code was uploaded without a license, it defaulted to All Rights Reserved. This does not bode well for the Xilinx legal department.

In any event, you really, really have to wonder what Xilinx’s internal documentation looks like if a random person on the Internet can discover a barely-documented protocol, write a daemon, put it on the Internet, and have someone at Xilinx use that code.

Thanks to the anonymous tipster for sending this into the Hackaday tip jar.