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, B training functionality associated with the cameras that is trained to recognize expected patterns in images to be acquired by them of the object, 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).