| 摘要 |
PURPOSE:To easily execute hidden line processing by simple operation restricted only to the specification of front and rear elements by forming a closed area by outermost side elements out of front side elements and changing rear side elements included in the closed area to hidden line expression. CONSTITUTION:A closed area is stored by extracting front side elements and sorting the outermost side elements and a part shown by a slash part in Fig.(a) corresponds to the closed area on a two-dimensional plane. Then, a line of rear side elements is divided by the closed area. The state of this case is shown in Fig.(b) and the line of the rear side elements (2) is divided by the closed graphic (1). In the case of processing the inside of the closed area in the counter- clockwise direction e.g., the left side elements of respective intersecting points are deleted. The above processing is continued until the rear side elements disappear to easily complete hidden line processing. |
