| 摘要: |
| 研究了调节凸Bézier曲面、B-样条曲面及NURBS曲面(BBN曲面)一个控制点以后,曲面形状变化的规律.通过将BBN曲面分解成一张凸曲面与具有特殊形状曲面的叠加,建立了曲面变形前后一些几何量与变形位移量之间的数量关系,得到了凸BBN曲面失去凸性的充分条件和判据.相应的结果可应用于调节与控制BBN曲面形状的算法设计. |
| 关键词: CAD造型 参数曲面 形状控制 算法设计 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(50175106);湖南省自然科学基金资助项目(99YJJ20051) |
|
| Analysis and Control of Shape Variation of BBN Surfaces |
|
WANG Xing-bo
|
| Abstract: |
| In this paper, the shape variation law of Bezier surfaces, B-spline surfaces and NURBS surfaces (BBN surfaces) is investigated under the modification of a control point of the surfaces. The relationship between the geometric elements of the surface before and after deformation and the deforming displacement is built up by decomposition a BBN surface into the summation of a convex surface and a surface with special shape. The law of a convex BBN surface losing its convexity is also obtained. The achievements in this paper can guide the algorithm design and shape control in CAD modeling. |
| Key words: CAD modeling parametric surface shape control algorithm design |
