| 摘要 |
PURPOSE:To prevent the redundant definition or processing of the apexes of an approximate polyhedron by evolving a polyhedron which approximates a display object or is equal to this object itself and defining a display 3-dimensional graphic with the apex information and the information on the evolving way to display the graphic. CONSTITUTION:A part of a broken line can be regenerated for a cube shown in a figure (a) as long as a part shown by a sold line of a figure (c) and the evolving way are known in a development (b). That is, the apexes V5 and V6 follow the apexes V8 and V7 at a part of a side face and a square is formed by the upper apexes V5, V1, V4 and V8 at the upper part of a square train on the side face together with a square formed by the apexes V6, V2, V3 and V7 formed at the lower part. Thus a polyhedron is approximated so that a display cube is evolved by a prescribed evolving way, and the cube is evolved in a due way. Then the redundant apexes are deleted by a rule decided in response to the evolving way in an obtained development, and the apexes are defined in the order subject to the rule. Thus an approximate polyhedron can be restored as long as the evolving way and the apex definition are known. Furthermore the processes including the conversion of coordinates, etc., can be minimized. |
