How do I find hash value of a 3D vector?

Question

I am trying to perform broad-phase collision detection with a fixed-grid size approach. Thus, for each entity\'s position: (x,y,z) (each of type float), I need to find which cel

Answer 1

here are a few references you could look at. Warren's papers discuss the hash algorithm in detail:

A parallel hashed Oct-Tree N-body algorithm

A portable parallel particle program

Answer 2

The grid approach is going to have problems near the boundaries of the grid boxes. Why not use BSP trees instead?

Answer 3

If someone is still interested in this, I figured out a solution that works over here:

http://www.gamedev.net/community/forums/topic.asp?topic_id=567378

Answer 4

My preferred hashing function for this kind of vector is to rotate the bits of each component by a different constant and XOR them together.

It's very fast, and the bit rotations are helpful to reduce collisions and ensure as much of the key space as possible is used.