Motion-based control of an electronic device uses an array of at least three reference elements forming a triangle. An image sensor (e.g., a video camera), which may be located on a user-manipulated device, captures an image of the array. The array image has a pattern formed by a nonparallel projection of the reference triangle onto the image sensor. The pattern carries information of the relative position between the image sensor and the reference element array, and changes as the relative position changes. The pattern is identified and used for generating position information, which may express a multidimensional position of the user-manipulated device with respect to three axes describing a translational position, and three rotational axes describing pitch, roll and yaw motions. The control system and method are particularly suitable for videogames.