Particles Collision Detection (QuadTree) HD

A demo shows how collisions between big number of particles can be detected efficiently using simple dynamic data structure "quad tree". Red circles indicate where the collisions occurred, the particles are moving randomly around the scene. Using this algorithm there is no need to calculate the distance between each single particle and other particles, it detects the collision just when 2 particles share the same node in particular predefined level in the tree. The more iteration, the more accurate the detection is, lower fps though. Without the collision indicator it can handle more than 1000 particles together with a good fps. I made this demo using C# and Unity3D. Thanks for watching