Interactive Visual Programming With Vvvv

Did you ever feel the urge to turn the power of image processing and OCR into music? Maybe you wanted to use motion capture to illustrate the dynamic movement of a kung-fu master in stunning images like the one above?  Both projects were created with the same software.

vvvv -pronounced ‘four vee’, ‘vee four’ and sometimes even ‘veeveeveevee’- calls itself ‘a multi purpose framework’, which is as vague and correct as calling a computer ‘a device that performs calculations’. What can it do, and what does the framework look like? I’d like to show you.

Since its first release in 1998 the project has never officially left beta stage. This doesn’t mean the recent beta releases are unstable, it’s just that the people behind vvvv refrain from declaring their software ‘finished’. It also provides an excuse for some quirks, such as requiring 7-zip to unpack the binaries and the UI that takes some getting used to. vvvv requires DirectX and as such is limited to Windows.

With the bad stuff out of the way, let’s take a look what vvvv can do. First, as implied by the close relationship with DirectX, it’s really good at producing graphics. An example for interactive video is embedded below the break. With its data flow/ visual programming approach it also lends itself to rapid prototyping or live coding. Modifications to a patch, as programs are called in this context, immediately affect the output.

The name ‘patch’ harkens back to the times of analog synthesizers and working with vvvv has indeed some similarities with signal processing that will make the DSP nerds among you feel right at home.

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Restoring A Tonka Truck With Science

The yellow Tonka Truck. Instantly recognizable by any child of decades past, that big metal beast would always make you popular around the sandbox. There were no blinking lights to dazzle, no noises to be heard (unless you count the hard plastic wheels rolling on concrete), even the dumping action is completely manual. But back then, it was a possession to be treasured indeed.

So it’s perhaps no surprise that there is a certain following for these classic trucks today, though like with most other collectibles, a specimen in good condition can be prohibitively expensive. The truck that [PoppaFixIt] found in the trash was certainly not one of those specimens, but with some patience and knowledge of basic chemistry, he was able to bring this vintage toy back to the present.

The first step was to disassemble the truck. Before they switched over to Chinese mass production, these trucks were built with actual rivets. After drilling them out and unfolding the little metal tabs that toy makers loved back in the day, he was able to separate the metal body of the truck from the plastic detail bits. The plastic parts just needed a fresh coat of paint, but the rusted metal body would need a bit more attention.

Remembering a tip he read online, [PoppaFixIt] decided to attempt electrolytic rust removal to get the metal parts back into serviceable condition. A big plastic bin, some washing soda, and old steel window weights for his sacrificial anodes was all the equipment he needed for the electrolysis tank. To power the chemical reaction he used a standard 12 volt car battery and charger wired in parallel; this step is important, as he notes most newer chargers are smart enough not to work unless they see a real battery connected.

After running the setup overnight, the collected rust and junk on the window weights was proof enough the process worked. From there, it was just a fresh coat of yellow paint, a new sticker kit from eBay, and his Tonka truck was ready to face another 30+ years of service.

If you’re looking to restore things larger than a child’s toy, you may be interested in the much larger electrolytic setup we’ve covered previously. Of course if you’re really pressed for time, you could try blasting the rust away with a laser.

Pi-Controlled Billy From The Saw Horror Flicks

[David0429] has made a very scary Raspberry Pi controlled puppet. Scary that is if you’ve seen the Saw movies where a serial killer uses one like it, called Billy, to communicate with his victims. If you haven’t, then it’s a pretty neat remote-controlled puppet-on-a-tricycle hack.

A stepper motor hidden under the front fender moves the trike by rotating the front wheel. It does this using a small 3D printed wheel that’s attached to the motor’s shaft and that presses against the trike’s wheel. Steering is done using a 3D printed gear mounted above the fender and attached to the steering column. That gear is turned by a servo motor through another gear. And another servo motor in the puppet’s head moves its mouth up and down.

All these servos and motors are wired to an Adafruit stepper motor HAT stacked on a Raspberry Pi hidden under the seat. Remote control is done from a webpage in any browser. The Flask python web framework runs on the Pi to both serve up the webpage and communicate with it in order to receive commands.

[David0429] took great care to make the puppet and tricycle look like the one in the movie. Besides cutting away excess parts of the trike and painting it, he also ran all the wires inside the tubular frame, drilling and grinding out holes where needed.  The puppet’s skeleton is made of wood, zip ties and hinges but with the clothes on, it’s pretty convincing. Interestingly, the puppet in the first movie was constructed with less sophistication, having been made out of paper towel rolls and papier-mâché. The only things [david0429] would like to do for next time are to quieten the motors for maximum creepiness, and to make it drive faster. However, the need for a drive system that could be hidden under the fender resulted one that could only work going slowly. We’re thinking maybe driving it using the rear wheels may make it possible provide both speed and stealth. Ideas anyone?

In any case, as you can see in the video below, the result is suitably creepy.

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