Abstract: An example system includes: a field arrangement unit for positioning a field object in a three-dimensional virtual space; a viewpoint setting unit for setting a viewpoint in the virtual space so as to have an overhead viewpoint with respect to the field object; a scrolling unit for moving the viewpoint or the field object so as to change an area of the field object included in a range of vision on the basis of the viewpoint set by the viewpoint setting unit; a field deformation unit for deforming a shape of the field object such that a front side of the range of vision becomes flat while a back side of the range of vision is curved in a direction away from the viewpoint in accordance with a movement performed by the scrolling unit; and an image processing unit for generating a two-dimensional image displayed on a display unit.

Abstract: An X-Y direction input device includes a ball, a switchboard carrying push switches, first and second follower rollers rotated by the ball having axes perpendicular to each other, and rotation detecting means which all are enveloped by an outer shell. The push switches are activated by switch activating members exposed on the outer surface of the outer shell. The axes of the first and second follower rollers may be rotated by a desired angle with respect to an orientation of the outer shell.