1. A method, comprising: receiving a ray of a set of rays, the ray having an origin and a direction; sorting the rays into a directional group of a plurality of directional groups, each directional group having a corresponding directional range and comprising rays of the set of rays having directions within the corresponding directional range; and generating a conical boundary for the rays of a directional group of the plurality of directional groups, comprising: determining an axis for the conical boundary, the axis comprising an average direction of the rays of the directional group; determining a set of deviations of the rays of the directional group from the average direction; generating a circular boundary for the conical boundary, the circular boundary encompassing a ray having a greatest deviation from the average direction; generating an apex for the conical boundary such that the conical boundary comprising the circular boundary and the apex encloses the rays of the directional group; and generating a base of the conical boundary such that the base encircles a ray origin of a ray of the directional group that is closest to the apex in the average direction dimension.