1. A non-stochastic method of specifying geometric particle pathways using ray sets comprising: employing one or more paths traversing a local system of neighboring voxels relative to a reference voxel volume or surface, said ray sets comprising: a detail of the ray set traversal path through a system of voxels; a specification linking ray sets emanating from a local voxel group to ray sets of adjacent local voxel groups; a plurality of representative rays of varying length traversing a local system of neighboring voxels relative to a reference voxel volume or surface, the plurality of rays being distributed at different angles from a source; a fraction representing particles with a wave source probability distribution relative to a specified emergent particle distribution; lengths associated with the plurality of rays within each traversed voxel; and using said lengths in computation by one or more processors, and producing an output indicative of the specified particle pathways.