1. A program product for generating an image of a virtual three-dimensional space viewed from a virtual camera, wherein said program product causes a computer to function as: a model arrangement unit for arranging a model configured by intersecting a plurality of plate-shaped polygons in said virtual three-dimensional space; a parameter calculation unit for calculating a parameter dependent on an angle formed from a first vector set in association with said model and a second vector set in association with the line of sight of said virtual camera; a polygon selection unit for selecting as a display target one among said plurality of plate-shaped polygons configuring said model according to said parameter; a mapping unit for mapping a prescribed texture to said plate shaped polygon selected with said polygon selection unit; and an image generation unit for generating a two-dimensional image obtained by performing perspective projection to the inside of said virtual three-dimensional space, in which said model mapped with said texture is arranged, on a perspective projection plane set in correspondence with a visual point of said virtual camera.