The ‘257 patent describes a system which can be used in sports games such as baseball where player movement can be tracked by a position indicator. Whenever a ball is hit off the bat the outfielder should react to the ball. If the player can move his character in position to catch the ball, then the invention enacts a sequence which allows the player to catch the ball. If the player misjudges the location of the ball, however, the character is more apt to drop the ball or miss the catch.
In order to realize the smooth display of a fielder’s ball-catching movement, determination of a collision between a batted ball and a fence by an easy method, and an accurate hidden-face treatment for polygons which are located very close to each other, virtual area producing means 31 is provided to produce a collision area for collision determination at a position away from the picture of a ball for a predetermined distance, and determining means 32 is provided to determine at which position in the collision area a fielder is located. When it is determined that the fielder is located in the collision area, picture changing means 33 gradually changes the posture of the fielder from a waiting state to a ball-catching state.
1. A picture processing device comprising: coordinate converting means for projecting a group of polygons represented in a three-dimensional coordinate system on a two-dimensional coordinate system; and hidden face treatment means for determining a display order of the polygon group relative to other polygons projected on the two-dimensional coordinate system, wherein the display order is determined based on dimensions of the depth-directional coordinate values of said three-dimensional coordinate system in a display screen and based on the depth-directional coordinate values of a representative polygon within the polygon group, and wherein the hidden face treatment means includes means for displaying polygons within the polygon group in accordance with a predetermined description order when the display order of the polygon group indicates that the polygon group is to be displayed.