When spheres touch each other or the boxes, they become more red. The spheres gather to make the outline of a bullet and then are shot into the pile of boxes. Once the boxes are touched by a sphere, they become deactivated, not glowing any longer. The spheres then form the letters ‘OF’ toward the end of the video.
Runs in real time without the glow filter, which is not very apparent in this video. With the glow filter shown in this video, it stays around 50 fps.
Created with OpenFrameworks http://www.openframeworks.cc/
using the Bullet 3d physics library http://bulletphysics.org/wordpress/