I'm a big fan of spatial grid hashes to simplify situations like this. Nice to see other approaches. Iterative Insertion sorting would be easier to port to a compute shader than a spatial grid hash, so maybe this method is better if we get into the millions of objects range?
Isn't spatial hashing most suited to colliding objects of similar sizes, and with similar dimensions in each axis? (So you can match the grid size accordingly)
If you've got a mix of very different sizes and shapes, I think sweep and prune can be a better choice
Who specifically mentions what? Unless I'm missing something, nether TFA or the comment I replied to specifically mentioned the objects being similar size.
