| 摘要 |
PURPOSE:To reduce the burden of operation to increase the display speed by dividing a hexahedral element into plural tetrahedrons and calculating intersections between a prescribed plane and edge lines of tetrahedrons and sorting calculated intersections at need. CONSTITUTION:A cutting plane for section display is held in a cutting plane holding part 1. A hexahedron dividing part 3 divides the hexahedron held in a hexahedron holding part 2 into plural tetrahedrons. An intersection calculating part 4 calculates intersections between the cutting plane and edge lines of each tetrahedron. A sort need discriminating part 5 discriminates whether sorting is necessary or not according as the number of intersections is 4 or 3. When it is 3, it is discriminated that sorting is necessary. If sorting is necessary, intersections are sorted by a sorting part 6, and painting-out plotting accompanied with shading is performed by a painting-out plotting part 7. If sorting is unnecessary, painting-out plotting accompanied with shading is performed based on obtained intersections by the painting-out plotting part 7. |
