Common misconception. It is not related to space-filling curves. Space-filling curves are for linearizing points but have limited utility for interval data types. Technically though, all binary space decompositions can be described in terms of space-filling curves. However, for most kinds of space decomposition it is a mistake to use something describable on a fixed curve (e.g. Hilbert); the curve definitions are dynamically constructed and expressed in terms of a simple algebra. In extremely adaptive representations that squeeze as much information theoretic locality as possible out of the data model, those expressions can be pretty long but from a software standpoint you only need to reason about a local fragment of the expression at any point in the processing.<p>In SpaceCurve, all points are represented as hyper-rectangles. Literally everything is a hyper-rectangle. It is the most unusual part of the whole thing. There is no linearization on a space-filling curve.