Circle Pile

While this video showcases the stability and scalability of the simulator, it also shows a bug - after the circles have come to rest in a large pile, they gradually but steadily compress, moving closer and closer together even though they should be rigidly colliding

This drift occurs naturally due to floating point inaccuracies and discretization errors when integrating the equations of motion. Sophisticated solutions exist, but a simple, efficient, and commonly-used technique to prevent drift is to make collision impulses stronger when objects are colliding more deeply. This can introduce artificial energy into the system and may give obstacles an unrealistic bounciness if not carefully tuned. However, in many practical cases, it works very well.

This simple form of stabilization is used in the other demos, but in this demo, it is disabled to highlight its important effect on stability.