Custom software (color, silent), computer, projector, wooden discs
Position a circle at the center of a rectangular surface. Set its diameter to larger than the longest edge. Set the center of the circle as the origin for a large group of Element 1. When each element moves beyond the edge of the circle, move its position back to the origin. Draw a line from the centers of Elements that are touching. Set the value of the shortest possible line to white and the longest to black, with varying grays between.