| 摘要 |
PROBLEM TO BE SOLVED: To fast and accurately decide a hit with a three-dimensional model composed of a plurality of polygons. SOLUTION: The vertex coordinates of a partial model constituting the three-dimensional model are represented by center coordinates being the average value between the maximum value and the minimum value of each coordinate component, an enlargement/reduction ratio for being a prescribed value by being multiplied by the difference between the maximum value and the minimum value of the each coordinate component and a converted vertex coordinates obtained by multiplying a matter obtained by subtracting the center coordinates from each vertex coordinates by the enlargement/reduction ratio, the center coordinates and the enlargement/reduction ratio are stored in a floating decimal fraction type, and the converted vertex coordinates are stored in an integral type (ST3). A decision object partial model being a partial model defined as the object of hit decision is selected among partial models constituting the three-dimensional model (ST1), and the decision object partial model is subjected to hit decision (ST7 to ST11). |
