1. A non-transitory computer-readable medium having computer-executable instructions for causing a computer system to perform a method comprising: providing a binary tree comprising a plurality of leaf nodes and a plurality of internal nodes, wherein each of said plurality of internal nodes is uniquely associated with two child nodes each comprising either an internal node or leaf node; and determining a plurality of bounding volumes for nodes in said binary tree by traversing said binary tree from said plurality of leaf nodes upwards toward a root node, wherein a plurality of paths from said plurality of leaf nodes to said root node are processed in parallel, and wherein each parent node is processed once by a later arriving corresponding child node.