计算机辅助设计与图形学学报
計算機輔助設計與圖形學學報
계산궤보조설계여도형학학보
JOURNAL OF COMPUTER-AIDED DESIGN & COMPUTER GRAPHICS
2015年
6期
1091-1098
,共8页
双奇次%非均匀代数双曲T样条%局部细分%调配函数%线性无关
雙奇次%非均勻代數雙麯T樣條%跼部細分%調配函數%線性無關
쌍기차%비균균대수쌍곡T양조%국부세분%조배함수%선성무관
odd bi-degree%non-uniform algebraic hyperbolic T-splines%local refinement%blending functions%linear inde-pendence
针对 T 样条无法精确表示双曲超越曲面的问题,构造了一种样条曲面——双奇次代数双曲 T 样条曲面(NUAH T样条),探讨了其细分算法和调配函数的线性无关性。通过将非均匀代数双曲B样条曲面(NUAH B样条曲面)定义在T网上,给出了双奇次NUAH T样条的定义;基于NUAH B样条的节点插入公式,提出NUAH T样条的一种局部细分算法;并证明了NUAH T样条的调配函数线性无关的充要条件,即由NUAH T样条转化为NUAH B样条曲面的过渡矩阵是满秩矩阵。最后,通过实例验证了曲面构建和细分算法的有效性。
針對 T 樣條無法精確錶示雙麯超越麯麵的問題,構造瞭一種樣條麯麵——雙奇次代數雙麯 T 樣條麯麵(NUAH T樣條),探討瞭其細分算法和調配函數的線性無關性。通過將非均勻代數雙麯B樣條麯麵(NUAH B樣條麯麵)定義在T網上,給齣瞭雙奇次NUAH T樣條的定義;基于NUAH B樣條的節點插入公式,提齣NUAH T樣條的一種跼部細分算法;併證明瞭NUAH T樣條的調配函數線性無關的充要條件,即由NUAH T樣條轉化為NUAH B樣條麯麵的過渡矩陣是滿秩矩陣。最後,通過實例驗證瞭麯麵構建和細分算法的有效性。
침대 T 양조무법정학표시쌍곡초월곡면적문제,구조료일충양조곡면——쌍기차대수쌍곡 T 양조곡면(NUAH T양조),탐토료기세분산법화조배함수적선성무관성。통과장비균균대수쌍곡B양조곡면(NUAH B양조곡면)정의재T망상,급출료쌍기차NUAH T양조적정의;기우NUAH B양조적절점삽입공식,제출NUAH T양조적일충국부세분산법;병증명료NUAH T양조적조배함수선성무관적충요조건,즉유NUAH T양조전화위NUAH B양조곡면적과도구진시만질구진。최후,통과실례험증료곡면구건화세분산법적유효성。
Since T-splines cannot represent hyperbolic spline surfaces exactly, this paper presents a kind of spline surfaces, called non-uniform algebraic hyperbolic T-spline surfaces (NUAH T-splines for short) of odd bi-degree. The NUAH T-splines are defined by applying the T-spline framework to the non-uniform al-gebraic hyperbolic B-spline surfaces (NUAH B-spline surfaces). Based on the knot insertion of NUAH B-splines, a local refinement algorithm for NUAH T-splines of odd bi-degree is shown. This paper proves that, for any NUAH T-spline of odd bi-degree, the linear independence of its blending functions can be de-termined by computing the rank of the NUAH T-spline-to-NUAH B-spline transformation matrix. Finally, the examples verify the effectiveness of the local refinement algorithm of NUAH T-splines.