rockabit

Check out the new website started by Rick Companje: www.flexotic.nl

It contains thoughts, experiments, tutorials, components and other stuff, all concerning Flex. Keep an eye out for interesting stuff on this website.

These patterns I made with the l-system application from the previous post, just by experimenting with one rule and changing the angle of rotation! The rule was F -> F+F-F+F and apparently it gives a lot of spirograph-like effects. I also really like the last one, it looks like the pink panther (including the body)

As always, click the images to see them at full size.

I’ve made a small application in Flex to draw l-systems with.
The previous post explains what l-systems are exactly, but here are the rules again in short:

L-systems is a grammar describing the growth of plant-like structures. It is made up of simple drawing commands and rules how these change during growth. For example, you start out with the command ‘F’ meaning draw one unit. You add a rule that says ‘change F to F+F-F’ where ‘+’ and ‘-’ mean turn left and right, respectively, with a predefined angle. Then, as it grows, the sequence of commands grows longer and more complex, as every time each ‘F’ is replaced by ‘F+F-F’ until you end up with a long sequence of simple commands that make up a complex shape. Add branching with the ‘[' (start branch) and ']‘ (end branch) characters and you can quickly create nice plant structures.

Try out the application here. It’s a small first version with some limitations, such as a maximum amount of drawing commands to prevent slow processing times, the possibility to define only one rule, and the fact that it always starts out with ‘F’. You can define your own rule of how ‘F’ changes (using F, +, -, [ and ]), you can set the angle of rotation and the amount of iterations to define the complexity of the resulting shape. If responses are too slow, you can turn off ‘update realtime’ and hit the ‘go’ button to calculate your l-system.

The Interactive Morphogenesis project, which I made a while ago with Rick Companje and Irad Lee, has been accepted for the Areas of Conlu(x)ence conference in Rumania.

Areas of conflu(x)ence proposes an international debate on the relationship between art and technology in the present digital era, focusing on the impact of the new media in our lives.

The project has to do with l-systems, which are mostly used to model plant growth. As Wikipedia puts it:

An L-system or Lindenmayer system is a formal grammar (a set of rules and symbols) most famously used to model the growth processes of plant development, but also able to model the morphology of a variety of organisms. L-systems can also be used to generate self-similar fractals such as iterated function systems.

To explain it in a bit more detail: take a string, say “F” and define a rule saying how this “F” changes, for example “F->F+F-F”. This has the effect that you can iterate over the string, each time replacing each “F” with “F+F-F”. After three iterations the string would have become “F+F-F+F+F-F-F+F-F+F+F-F+F+F-F-F+F-F-F+F-F+F+F-F-F+F-F”. Now imagine these different characters to represent drawing commands, where in this case F means draw a line in the current direction and + and - mean turn left or right by, say, 45 degrees. These few simple rules can lead to very complex and very beautiful structures being drawn, such as the famous Koch Curve, which is not exactly plant-shaped but does convey the complexity and beauty hidden within the simple grammar of l-systems:

We used this grammar to create a generative art piece which uses sound input to generate an l-system, visualize it, and convert it to sound output as well. We also customized it a bit to make it 3D and we let it move to environmental sounds as well. There’s an active demo where you can simulate the influence of sound by moving you mouse cursor to make the shape move. Also be sure to check out the website

(article in Dutch)

Noorderlicht Nieuws: Gekkotape overtreft gekkovoet
“Haartjes op de uiteinden van haartjes, dat blijkt het geheim van de gekkopoot. Daarmee kan de hagedis tegen muren op lopen en zelfs ondersteboven bijven hangen. Synthetische gekkopoottape met zulke haren-op-haren blijkt zelfs beter te plakken dan de gekko zelf.”
(lees het volledige artikel)

Geweldig! Ik kan niet wachten tot ik elke willekeurige wolkenkrabber kan beklimmen met mijn eigen gekkopak.

Wednesday we came back from Salzburg, after having spent two days on the PerGames conference with our ShameStation project. It was a lot of fun, Salzburg is a nice town, great for spending a weekend in
The conference was a lot of fun as well. Many interesting projects, posters and talks and everyone liked our ShameStation. Even though we didn’t get too much sleep with all the driving to Austria and back and the getting up early, it was still a great little mini-vacation and a nice experience.

I’m very excited about going to Austria this weekend. Nicolette and I are going to PerGames, a conference on pervasive gaming, and the ShameStation project we created together with Jeroen (who sadly can’t join us) is going to be there as a live demo. Needless to say, we wanted to upgrade it a bit to look its best and I think it turned out great with our new helmet. It’s a fireman’s helmet with a wireless camera and wireless headphones integrated and it will give you optimal control over another person when you’re having him spray water onto innocent and unsuspecting bystanders (muhahaha)!

before: after:

If you want to know more about the ShameStation, just check the ShameStation website.

So here’s the story: for my graduation project I need, amongst lots of other things, to drive a DC motor, which anyone who has some experience with building circuitry will tell you is not so big a deal. Except this motor is, because it typically requires around 4 amps to operate, which can go up to 6A when it’s moving a heavy load. Now this is not so much the problem, because I have the power supply required, but I just need to lower the voltage to make it go slower. Oh, and did I mention it’s reversible? I’m sure many hardware gurus will be scratching their chins right about now, going “hmmm”. I know I was, but then again I’m far from being a hardware guru, I’m just learning.
Anyway, back to the story. Apparently, lowering the voltage for a reversible DC motor whilst delivering 4 to 6 amps is not something that’s easily done. It needs a bunch of circuitry. Long story short: I meet this guy (Daniel, you rule) who likes to build circuitry in his spare time and he agrees to help me with this. So finally, after struggling on this problem for months (well, maybe not months and maybe not just this problem, but a long time anyway) I end up with a schematic of a circuit that simulates great in software and I build it on my breadboard (see pictures). I check, I double check, I measure with low voltage, I measure with the power supply I’ll be using, and it works. Woohoo, it works! And then I plug in the motor…
First, the motor starts moving hesitantly. Then it picks up a bit of speed and does what I want it to. It moves, and at exactly the right speed. I remember thinking: “Thank god, I’m done with this whole motor driving circuit thing”. But then I hear the nerve-wrecking *POOF!*. A lot of smoke, a vile smell and the sound of electrical sparks. I immediately pull the plug, but needless to say it was too late (as is often the case when you’ve witnessed your chip explode). Turns out I should have been cooling the chip…

circuit on the left, cracked chip with melt spots on the right (click to enlarge)

The PerGames conference in Austria is approaching rapidly, so I’ve renewed the website for the ShameStation project. If you want to know what I’m talking about, just check out the website at www.rockabit.com/shamestation. Enjoy

I gotta say: wow! I had a great experience this week, because I’m a subject in a research for which I have to play a computer game with my thoughts!
It’s called BCI, for Brain-Computer Interface, and you have to wear a really silly-looking cap stuffed with electrodes. Using the signals from the electrodes, your thoughts are read. Not the words, thank god, but your intention to move. The theory is like this: when you are commanded to move say your finger and you move your finger, a certain area of your brain activates. When you decide on your own to move a finger, this same area in your brain activates, along with another area concerning your decision to move that finger. This can be read through EEG and can therefore be used to control, in this case, a computer game!

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