This is a demo of creating and visualizing magnetic (kind of) fields in Processing and controlling with a tangible multitouch table and Quartz Composer. It gets more interesting after the 1 minute mark :P

The demo came about as a digression off the Roots project I'm working on with Jordan & Owen - makers of the Bricktable (bricktable.wordpress.com/). You can read more about the Roots project at memo.tv/roots_creating_and_visualising_generative_music_on_a_tangible_multi_touch_table and bricktable.wordpress.com/about/what-is-roots/ .

The visuals you see here, are created by placing fiducial markers on an interactive surface. You can see when the marker is pointing right (green) it acts as an attractor, and when it is pointing left (red) it acts as a repeller, with the amount of rotation determining how much it attracts or repels - and its physical size. Varying configurations of layout and rotation creates interesting patterns in the force field.

In addition, on the right you can see a Quartz Composer window. I use QC to quickly knock up a control interface, and control parameters in Processing, sending the slider info over to Processing via OSC. Being able to change things like maximum force, drag, size etc in realtime without cluttering the Processing render window is quite useful.

In the Roots project, this visualization is secondary to the main purpose of the app. By placing and playing with the fiducial markers you can control the force field in the environment. The heroes of the app - the Roots - move around affected by those forces and ultimately control the fate of the music. For the finished Roots app I'm not sure if the force field visualization will be like this as its early days yet... but I'm looking forward to the evolution of what it will become :P

Written in Processing 0135 using the reactivision library.

Stay tuned for more info and footage of the actual Roots...

More info at memo.tv/magnetic_force_fields_in_processing_controlled_by_multitouch_quartz_composer