| 摘要 |
PURPOSE:To improve the value in use of a bounding box to quickly judge an intersection by decomposing the space, where an object exists, to generate the bounding box and disjudging the intersection to the ray. CONSTITUTION:An object condensation point calculating part (for example, an object centroid calculating part 26, a modeling coordinate origin calculating part 27, or an object apex calculating part 28) 22 calculates condensation points of objects generated in the space. A space subdividing part 23 divides the space, and division is repeated if the object number density obtained by dividing the number of objects by the volume (or the area) is lower than a division allowable value (except in the case of (the number of objects) = 0). A bounding box calculating part 24 stores a rectangular parallelepiped (or a rectangle), which includes objects in the space where the object number density is made higher than the division allowable value, as the bounding box in a bounding box list 25. |
