A method includes: receiving, in a first device, a relative description file for physical markers that are positioned at locations, the relative description file defining relative positions for each of the physical markers with regard to at least another one of the physical markers; initially localizing a position of the first device among the physical markers by visually capturing any first physical marker of the physical markers using an image sensor of the first device; and recognizing a second physical marker of the physical markers and a location of the second physical marker without a line of sight, the second physical marker recognized using the relative description file.