| 摘要 |
PURPOSE:To shorten time necessary for calculating a sectional graphic obtained by a solid and a plane by decreasing the number of partition surfaces for which a intersection check is to be executed. CONSTITUTION:A plan 10 is set, the intersection between a surface 102 to partition a solid 101 first and a finite surface 112 is checked, and a node 110 is made into a black point. Finite surfaces 113 and 114 are assigned to areas 115 and 116. After that, the above-mentioned processing is repeated in the same manner up to a low-order node. As the result, lastly, a graphic, which is composed of plural finite surfaces and reflects the all the intersections between the finite surfaces and the partition surfaces, is completed. For example, when the finite surface 114 never intersects with a partition surface 117, this finite surface is included in one area partitioned by the partition surface, the finite surface is assigned to a node to indicate the area at a finite surface existing side, and while processing is continued in the assigned area, the processing is stopped in another area to which the finite surface is not assigned. For a node 120, namely, for a partition surface 108, the intersection check is not executed. As the result, the number of intersection checks can be decreased, and sectional graphic calculating time cna be shortened. |
