1. In a computer-based system having a display and a controller device for interfacing with an interactive program, a method for determining the position of the controller device, the method comprising: (a) initializing the computer-based system to establish a starting position of the controller device relative to the display, the initializing including, (i) capturing an image of the display using a camera integrated in the controller device; (ii) capturing an image of a radiation pattern projected by the controller device; and (iii) analyzing the captured image of the display and the image of the radiation pattern projected by the controller device to determine a size of the display in the captured image at a distance of the controller device as determined by the image of the projected radiation pattern; (b) capturing successive images of the display at the controller device; (c) determining a position of the controller device relative to the display based on a perspective distortion of the display in the captured successive images of the display; (d) providing the determined position of the controller to the computer-based system to interface with the interactive program to cause an action by the interactive program.