1. A method of three-dimensional (3D) vision for determining at least one of a position and orientation of an object in three dimensions, the method comprising A. calibrating multiple cameras that are disposed to acquire images of the object from different respective viewpoints to discern a mapping function that identifies rays in 3D space emanating from each respective camera's lens that correspond to pixel locations in that camera's field of view, wherein the calibrating step includes determining, from images acquired substantially simultaneously by the multiple cameras, correlations between positions in 3D space and pixel locations in each respective camera's field of view, B. training functionality associated with the multiple cameras to recognize expected patterns in images of the object acquired by different ones of the multiple cameras, and training that functionality in regard to reference points of those expected patterns, such that training as to those expected patterns facilitates insuring that the reference points for those patterns coincide as between images obtained by those cameras, and C. triangulating locations in 3D space of one or more of the patterns from pixel-wise positions of those patterns in images of the object and from the mappings discerned during step (A).