Each cell is a bucket of game objects and a unique hash id. It’s a simple premise really, any item in bucket 3 for example, cannot possibly collide with something in bucket 9.
If we imagine the bucket as a list of 16 buckets, 0-15 cells and placed the game objects in that bucket. This reduces the amount of times we need to cycle the nearby objects but also dramatically reduce the amount of times we need to check if a collision is happening.
Due to my brute force nature if I had 10 monsters in the world there would be 10*10 = 100 collision checks in every update.
Now ramp the number up to 100 to be a bit excessive and we end up with 100*100=10,000 collision checks.
I then populate a List We create a new class to store the grid data in including the buckets.
June 13, 2009 at pm (Other Stuff, XNA) (2D, C#, COl LISION DETECTION, SPATIAL HASHING, XNA) This is a sample prototype I wrote to fix a performance limitation with collision checking in SBARG. Here is a good 1 liner I will borrow from the source material i used.
“Spatial hashing is a process by which a 3D or 2D domain space is projected into a 1D hash table.” Optimization of Large-Scale, Real-Time Simulations by Spatial Hashing So why do we need it?
The general form of the nearest neighbor query is: “”; this is the query pattern used by location-aware applications to find POIs close to the user’s current location, for example.
However, another pattern of which I’ve seen much fewer examples is how to update an entire table of records in order to determine and populate the nearest neighbour for each row in the table (indeed, this very question came up on the MSDN spatial forum just last week).
If we were just checking the position of the game object the calculation would be. This uses the Get Id For Obj method and populates a list of Game Object’s and returns once complete.