图学学报
圖學學報
도학학보
Journal of Graphics
2015年
3期
356-362
,共7页
刘植%李晨%谢进%费腾
劉植%李晨%謝進%費騰
류식%리신%사진%비등
Bézier曲线%奇点%拐点%曲线形状%形状参数
Bézier麯線%奇點%枴點%麯線形狀%形狀參數
Bézier곡선%기점%괴점%곡선형상%형상삼수
Bézier curve%singular points%inflection points%curve shape%shape parameter
为了分析清楚形状参数对一类双参数三次Bézier曲线形态的影响及实现其对该曲线形状的调控,利用包络理论与拓扑映射的方法对一类双参数三次Bézier曲线进行了形状分析,明确了形状参数对曲线的影响,画出了曲线的形状特征分布图,得出了曲线上有奇点、拐点和曲线为局部凸或全局凸的充分必要条件,这些条件完全由控制多边形的相对位置表示,并进一步讨论了形状参数对曲线形状的影响。
為瞭分析清楚形狀參數對一類雙參數三次Bézier麯線形態的影響及實現其對該麯線形狀的調控,利用包絡理論與拓撲映射的方法對一類雙參數三次Bézier麯線進行瞭形狀分析,明確瞭形狀參數對麯線的影響,畫齣瞭麯線的形狀特徵分佈圖,得齣瞭麯線上有奇點、枴點和麯線為跼部凸或全跼凸的充分必要條件,這些條件完全由控製多邊形的相對位置錶示,併進一步討論瞭形狀參數對麯線形狀的影響。
위료분석청초형상삼수대일류쌍삼수삼차Bézier곡선형태적영향급실현기대해곡선형상적조공,이용포락이론여탁복영사적방법대일류쌍삼수삼차Bézier곡선진행료형상분석,명학료형상삼수대곡선적영향,화출료곡선적형상특정분포도,득출료곡선상유기점、괴점화곡선위국부철혹전국철적충분필요조건,저사조건완전유공제다변형적상대위치표시,병진일보토론료형상삼수대곡선형상적영향。
The shape features of a class of Bézier curve with two shape parameters are analyzed by using the method based on the theory of envelope and topological mapping. Investigate effects of the shape parameter on the curve shape. Necessary and sufficient conditions are derived for this curve having one or two inflection points, a loop or a cusp, or be locally or globally convex. Those conditions are completely characterized by the relative position of the edge vectors of the control polygon. Furthermore we discussed the influences of shape parameter on the shape diagram and the ability for adjusting the shape of the curve.