1. A system for a 3 dimensional (3-D) user interface, the system comprising: one or more 3-D projectors configured to display an image at a first location in a 3-D coordinate system; one or more sensors configured based on quadrilateral angle navigation to sense user interaction with the image and to provide user interaction information; and a processor configured (i) to receive the user interaction information from the one or more sensors; (ii) to correlate the user interaction with the image; and (iii) to provide one or more indications responsive to a correlation of the user interaction with the image, wherein the one or more indications comprise displaying the image at a second location in the 3-D coordinate system.