1. A method for automatic toolpath generation, comprising: receiving a first virtual part from a user account, the first virtual part comprising a first plurality of part features; receiving a second virtual part comprising a second plurality of part features; selecting the first and second virtual parts for concurrent manufacturing; determining a relative arrangement of the first virtual part with respect to the second virtual part; for each part feature of the first and second pluralities, determining a feature class for the part feature, wherein the determined feature class is one of a predetermined set of feature classes; for each part feature of the first and second pluralities, determining an ordered series of tactics based on the respective feature class, wherein each successive tactic within an ordered series is dependent upon a preceding tactic within the ordered series; ordering the tactics from all part features of the first and second pluralities into a master series while preserving the tactic dependencies; determining a toolpath primitive for each tactic based on the respective tactic and geometry of the respective part feature; combining the toolpath primitives for the tactics based on the master series and the relative arrangement to generate a master toolpath, the master toolpath comprising: a first toolpath primitive for a part feature of the first plurality; a second toolpath primitive for a part feature of the second plurality, immediately following the first toolpath primitive; and a third toolpath primitive for the part feature of the first plurality, following the second toolpath primitive; translating the master toolpath into machine code; and concurrently manufacturing a first and second physical part by controlling a machine according to the machine code, wherein: the first physical part is associated with the first virtual part; the second physical part is associated with the second virtual part; the first and second physical parts are each of unitary construction; during manufacturing, the first physical part is arranged in the relative arrangement with respect to the second physical part; and after manufacturing, the first physical part is physically distinct and separate from the second physical part.