摘要
定义了曲面的Ｇ２连续性，利用Ｂｅｔａ样条函数构造出了Ｇ２连续的Ｃｏｏｎｓ双三次曲面片，它克服了传统Ｃｏｏｎｓ曲面的两个缺点，它的特点是连续阶高及有两个可以控制曲面形状的自由参数，它特别适合于自由型曲面的设计。
To date CAD designers have found the frequently used bicubic Coons patches inconvenient in two respects: (1) local modifications not convenient and (2) C 2 continuity too restrictive. In order to help CAD designers to reduce greatly the abovementioned inconveniences, I used βsplines as blending functions to construct a new kind of bicubic Coons patches. I derived Eqs.(4) through(9). Because two parameters β 1 and β 2 in Eqs.(4) through (9) can be freely selected by the designers, the shapes of the patches can be changed without changing the boundary information of the patches, and if we let β 1=1 and β 2=0, my G 2 bicubic Coons patches become C 2 bicubic Coons patches. Both local modifications without affecting adjacent patches (Fig.1) and design of triangular surface (Fig.2) are possible with my bicubic Coons patches.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1997年第1期145-150,共6页
Journal of Northwestern Polytechnical University
