1. A method comprising: spatially partitioning bodies in a multi-body system to a plurality of computational nodes, each computational node including a processor and associated with memory for maintaining data; at each of the plurality of computational nodes, maintaining data for a different subset of the bodies in the memory associated with said node; at a first node of the computational nodes, importing body data from a set of one or more spatially neighboring nodes of the plurality of computational nodes; and at the first node, computing data characterizing interactions between bodies using the processor of said node, including: computing data characterizing a first set of interactions among groups of bodies, each group including at least one body for which the first node maintains data and at least one body for which data is imported from the set of spatially neighboring nodes, and computing data characterizing a second set of interactions among groups of bodies, each group including only bodies for which data is imported from the set of spatially neighboring nodes.