Quad trees are popular because they're fairly easy to understand and implement, but they don't actually perform that well in practice for broadphase. (Its reall

Quad trees are popular because they're fairly easy to understand and implement, but they don't actually perform that well in practice for broadphase. (Its really more for LOD) If you want a tree that does perform well and is similarly easy to understand, a dynamic AABB tree is much better.