You have a lot of objects in your game and it is becoming costly to check each object against the rest for collisions. You want to answers to more complex physical queries than “Does A intersect B”. You would like a to perform some sort of path finding.

The grid pattern describes a way to partition objects according to their position in space. This allows you to quickly identify when two objects could not possibly be intersecting. Once in place, it's possible to leverage the grid for additional physical queries such as ray casting.

• Ray Casting
• Path Finding

For more information about the grid as well as example implementations please see the following:

• Physical Queries for the Math Challenged
• The N Tutorials