At its core, Magnetosphere is a physics system which plays opposing forces against each other. Some elements in the scene have an attractive force, others have a repulsive force, and over time these elements create dynamic compositions.
Since each particle is assigned a charge (positive or negative float values), it was easy to turn the system into an audio visualization. If you break up the incoming audio using FFT spectral analysis, it is a simple matter to assign each particle a specific frequency to pay attention to. This audio data can then influence the particles' charge and strength of the forces applied.
The earliest versions of this project were originally built in Processing. They were very graphic flat shapes with no lighting. I pulled colors procedurally from input photography.
Three images from an early version made with Processing in 2004-2005, and the amazing Magnetoquilt made by my mom.
As I got more comfortable with graphics coding, I began to abuse additive blending in OpenGL so that I could make things glow. And I made everything glow because it was must easier than making only a few things glow. No pesky occlusion and depth sorting to worry about. This began my additive blending phase which lasted over a year.
Magnetosphere in full glowing trippiness.
Stills from a presentation at UCLA showcasing the inner logic of the system.
Due to the success of this project, The Barbarian Group was asked by Apple to turn Magnetosphere into an iTunes visualizer. Friend and Rare Volume co-founder Andrew Bell was in charge of porting it from Processing to C++ and together we worked on making it run at interactive framerates.
In 2007, Magnetosphere became the default visualizer for iTunes.
Screenshots from the iTunes visualizer