quadtree != 2d tree

[browles]

Hey Drew, long time no see. This is my first time hearing about this meetup. Its been too long since I was last at HR.

Just want to point out that quadtrees are not k-d trees. The difference is pretty pronounced: quadtrees in 2D split cells into 4 quadrants (and octrees in 3D into 8 octants) whereas k-d trees split divisions into only 2 regions regardless of dimension (i.e. a Binary Space Partition). This property suggests that k-d trees scale much better than generalizations of quadtrees in higher dimensions (not that I have any experience doing that).