Neural radiance fields (NeRFs) is a technique to create models of complex 3d geometry from a set of photo/camera pose pairs. The way it usually works is that the 3d geometry you're interested in (a car, a tree, etc.) exists within a static, bounded space (e.g. a unit cube). This research changes that requirement, allowing you to create larger spaces without the memory and computational drawbacks of "just making the bounded space bigger."