Quadtree for 2D collision detection

Question

I\'m trying to use a quadtree for 2D collision detection, but I\'m a little stumped on how to implement it. First of all, I\'d have a quadtree which contains four subtrees (

Answer 1

Quad trees are not always the best data structure for collision detection. The overhead of a quadtree can potentially be unbounded (if you don't limit the depth of the tree), and in the worst case don't give any speed up at all. Instead, you might want to consider using a sparse grid, which gives better performance than a quadtree only without the extra overhead of traversing multiple tree levels.

There are also other completely different approaches which might be even better. For example, you could try implementing Zomorodian and Edelsbrunner's algorithm, as I did in the following module:

• https://github.com/mikolalysenko/box-intersect

Here are also some articles which I wrote that discuss these issues in more detail:

• http://0fps.net/2015/01/07/collision-detection-part-1/
• http://0fps.net/2015/01/18/collision-detection-part-2/
• http://0fps.net/2015/01/23/collision-detection-part-3-benchmarks/

In particular, if you look at the benchmarks in the last section you will see that of all the libraries surveyed, quadtrees tended to perform quite poorly compared to other collision detection methods like R-Trees, grids or segment trees.