| 摘要 |
PURPOSE: To make sure error free in the case of generating the contour line of a saddle plane. CONSTITUTION: Two kinds of different contour lines can be obtained in accordance with whether a face laterally cutting the saddle plane is located on the upside or downside of a saddle point M. While utilizing the height of the saddle point M, a computer system can decides which contour line is correct in each case. When storing paired intersections in the computer system two by two, the contour line is decided in the form of two intersections. Through rearrangement, exchange and link or the like, the adjacent relation of these paired intersections is confirmed and adjacentness is decided for respective intersections. With support due to these adjacentness data, the computer system can show a polygon composed of contours on an image screen. |
