摘要
针对由多张B-spline曲面拼接构成的曲面形状修改问题,提出了一种多张B-spline曲面变形算法。通过将曲面片控制顶点网格进行"合并"来建立多张B-spline曲面的刚架模型;以刚架节点位移为未知量,建立节点载荷最小和节点位移最小的统一优化目标函数;将曲面片之间的光滑拼接条件抽象为节点相对位置约束,结合点约束、点和法矢约束共同组成约束方程组;采用罚函数法求解得到变形后曲面新的控制顶点。变形实例表明该算法是直观有效的。
For the shape modification of surface connected by multi B--spline surfaces, a deforma- tion algorithm was presented. A uniform rigid frame model was created through merger of control mesh among the surfaces to illustrate the position of control vertexes of surfaces. The minimizations of the external load and node displacements were described in a uniform objective function with the displacement of node. Smooth connection relationship among different surfaces and geometric con- straints （point constraint, point and normal constraint） were extracted as constraint equations. The penalty function method was introduced to solve this problem. Experimental examples show that this algorithm is intuitive and accurate.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2013年第24期3355-3359,3365,共6页
China Mechanical Engineering
基金
国家自然科学基金资助项目(50805075
51075206)
江苏省高校优势学科建设工程资助项目
南京航空航天大学基本科研业务费专项科研资助项目(NS2010138
NP2011018)
关键词
计算机辅助几何设计
B样条曲面
形状修改
几何约束
computer aided geometric design
B--spline surface
shape deformation
geometric constraint
