A simple GC-friendly three-dimensional Bin (aka Spatial Grid) implementation.
When you’re done with the Bin, you should call Dispose() so its resources can be freed in their object pool. If you forget this, no harm will be done but memory will be GC’ed.
If you’re doing 3D, take a look at Bin2D<T>.
int gridWidth = 25; int gridHeight = 20; int gridDepth = 10; float cellWidth = 1; float cellHeight = 1; float cellDepth = 1; Bin3D<object> bin = new Bin3D<object>(gridWidth, gridHeight, gridDepth, cellWidth, cellHeight, cellDepth);
When you no longer need the Bin3D, you should call Dispose() on it:
Retrieving potential matches¶
You can retrieve a set of objects that potentially intersects an axis-aligned bounding box.
HashSet<object> results = new HashSet<object>(); var center = new Vector3(5, 5, 3); var size = new Vector3(2, 2, 1); Bounds queryBounds = new Bounds(center, size); bin.Retrieve(queryBounds, results);
You should recycle the results HashSet for future calls to avoid GC allocations. Remember to clear it before you reuse it.
object item = new object(); var center = new Vector3(4, 4, 4); var size = new Vector3(1, 2, 1); Bounds itemBounds = new Bounds(center, size); bin.Insert(item, itemBounds);
To remove an item you need to know the bounds that was used to add it.
In case you don’t know the previous bounds you can use Remove(item) which goes through every cell and removes the item. It’s much cheaper if you cache the bounds instead, but it’s there if you need it.
Updating an item’s bounds in the bin is easy. Just like when removing an item, you have to know the bounds that was used when adding it.
bin.Update(item, oldItemBounds, newItemBounds);
You can clear all items from the bin with Clear().