THREE-DIMENSIONAL IMAGE OUTPUT DEVICE AND BACKGROUND IMAGE GENERATION DEVICE

摘要

A projection (projected image) is drawn by perspective projection of a three-dimensional model with a background image having improved reality. When a sightline of the perspective projection looks down from above, the projected image is drawn into an object drawing area which is a lower part of an image picture. A background layer representing the stratosphere is separately generated by two-dimensionally drawing a background image, in which the stratosphere (hatched area) is opaque, while the remaining area is transparent. The boundary between the opaque portion and the transparent portion forms a curved line that is convex upward to express a curved horizon. The background layer is superimposed in front of the projected image, not behind the projected image, thereby covering an upper edge portion of the projected image including a straight-lined upper edge, so as to provide a curved boundary realizing a curved pseudo horizon in the image picture.