I wrote a general-purpose octree recently for my game Scraps. I was going to put in on the Unify Wiki but I'm waiting for them to approve my account, so I've put it up on GitHub: https://github.com/Nition/UnityOctree Before making this, I was looking for octree implementations and couldn't find anything that wasn't super basic or ancient, so maybe this can help to fill the gap a little. This is a dynamic, loose, general-purpose octree implementation. Someone can probably make it faster and better than I managed, but it may be useful to some. It's easy to use and pretty efficient.