Multi-resolution hash table space. This uses an internal data structure that records how each geom overlaps cells in one of several three dimensional grids. Each grid has cubical cells of side lengths 2^i, where i is an integer that ranges from a minimum to a maximum value. The time required to do intersection testing for n objects is O(n) (as long as those objects are not clustered together too closely), as each object can be quickly paired with the objects around it.
o-+ ode o-+ dcollider o-+ dspace o-+ dspacehash