Boids

Back in 1987 Craig Reynolds wrote his seminal paper Flocks, Herds, and Schools: A Distributed Behavioral Model. From applying a series of simple rules to a group of virtual birds (or Boids as Reynolds named them) the emergent behaviour of flocking arises.

The rules that update the birds (Boids) positions the virtual 3D world are as follows. (These images and descriptions come from Craig’s boids page).

Separation: steer to avoid crowding local flockmates

Alignment: steer towards the average heading of local flockmates

Cohesion: steer to move toward the average position of local flockmates

The “local flockmates” are a smaller group within the flock surrounding the current boid. Each boid only sees a small subset of the entire flock, yet when the rules are applied the entire flock acts as a whole. This is essentially what emergent behaviour means.

I have attempted boids simulations in the past, but the results never seemed to work out exactly as I wanted. Over the last few days I rewrote the boids code in Visions Of Chaos from scratch and am now getting some more realistic flocking behaviour emerging from only using the above rules.

Here is a quick sample with 2,500 boids. The “world” they live in is a cube with wrap-around edges, so you will see flocks exit one side and reappear at the other side. Must be watched full HD to see all the details.

Here is a more recent test run with 5,000 boids. Also a must see in HD.

And a final example with the boids confined to a rectangular room. The boids also leave fading trails behind them.

Jason.

The Sun and Saturn

NASA’s Astronomy Picture Of The Day always has interesting space related images and movies and is worth checking out on a regular basis. Here are two incredible recent movies APOD pointed to.

First up is this incredible HD solar prominence.

“When a rather large-sized (M 3.6 class) flare occurred near the edge of the Sun, it blew out a gorgeous, waving mass of erupting plasma that swirled and twisted over a 90-minute period (Feb. 24, 2011). This event was captured in extreme ultraviolet light by NASA’s Solar Dynamics Observatory spacecraft . Some of the material blew out into space and other portions fell back to the surface. Because SDO images are super-HD, we can zoom in on the action and still see exquisite details. And using a cadence of a frame taken every 24 seconds, the sense of motion is, by all appearances, seamless. Sit back and enjoy the jaw-dropping solar show.”

Make sure you click the fullscreen icon and select the full HD resolution to see this in all its glory.

Next is this footage of Saturn from the Cassini spacecraft. As Cassini was approaching and orbiting Saturn it took thousands of images. A bunch of those images have now been carefully cropped, rotated, digitally tweaked etc to create this awesome movie. Again, make sure you watch this in full screen mode.

Jason.

Fractal Flames reignited

After the recent updates I made to the flame mode I had planned to work on other new modes for Visions Of Chaos but instead I got hooked and kept working on the fractal flame mode. The latest version now has more variations and improved search and mutation features.

Here are a few recent renderings using the new version.

I have also updated the Fractal Flame Tutorial to help newcomers get to grips with creating their own fractal flames using Visions Of Chaos.

Jason.

GBK

A while back (actually a year and a half since the latest update) Ray Dulski (ArtCom) and I combined efforts to write a program called GBK to help people who use the guitar, bass or keyboard (hence the name) learn chords.

This was an interesting project. Ray spent much more time than I did on the database behind it that contains all the info for the what scale/key/variation/voicings each chord contains. The end result is not bad at all and has received good feedback from the musical community.

If you are a beginner who is learning the guitar (or bass or keyboard), GBK will save you having to use endless chord books or printouts of chords.

I have occassionally tried to write music myself (seems so easy when you hear a good song and think “I can do that”) and GBK has been a great help. At least it is a great help to allow me to make correct in tune sounding chords. Writing the actual music/tune is not simple. I am still searching for the holy grail of getting a program to write pleasing sounding music automatically.

Ray is much more the muso than I am.

Jason.