| 1. | This thesis studies the problems of geometric continuity in nurbs surfaces reconstruction
本文研究nurbs曲面重构中的几何连续性问题。 |
| 2. | Because geometric continuity is not relative to special parametrizations , it is applied in theoretical researches and engineer applications extensively
由于几何连续与具体的参数选取无关，因此在理论研究和工程应用中被广泛采用。 |
| 3. | ( a ) it summarizes geometric modeling on its development , its new methods , and further trend , and gives the theory of geometric continuity and blending surface
在此基础上根据几何连续与过渡曲面的密切相关性，重点介绍过渡曲面模型与几何连续的理论与性质。 |
| 4. | The aims of this thesis are researching some typical nurbs surfaces " geometric continuous conditions and pointing out the effects of knot vector and the degree of surface on geometric continuities
本文的目的是研究一些典型的nurbs曲面的几何连续条件，指出节点向量和曲面片的次数对几何连续性的影响。 |
| 5. | Blending surface plays an important role in cad / cam , and the problem of blending surface with high - degree geometric continuity is a key question . the paper concerns how to construct a blending surface between two surfaces
过渡曲面在cad cam技术中具有十分重要的地位，研究高阶几何连续过渡曲面的构造理论与方法是当前的研究热点之一。 |
| 6. | Many application examples show that this local b - spline surface designing strategy cannot only guarantee the quality of the surface , but also preserve the global geometric continuity of the whole cad model
大量的实际例子和操作表明，这种基于复杂裁剪边界约束的局部b样条曲面设计方案既能保证曲面模型的表面品质，同时又能保持曲面模型的全局连续性。 |
| 7. | Moreover , this thesis offers the mothod of generate smooth nurbs surfaces over arbitrary quadragulation . this mothod overcomes the defects of adopting so called simple collinear continuous condition to deal with the problem of geometric continuity
并针对任意拓扑的四边形剖分，给出了构造光滑nurbs曲面的方法，克服了采用所谓的简单共线法处理几何光滑连接的缺陷。 |
| 8. | With energy method , we can conveniently control the precision of the objective surface and add boundary constraints for preserving the model ' s global geometric continuity , but this method is very time - consuming . stiffness adjustment is the easiest method to be implemented and the fairing result is always satisfying except that the acquired surface editing is awkward . based on wavelets decomposition , the surface model ' s data size can be compressed efficiently and this method is running fast , however , the error and boundary constraints are difficult to be considered
其中基于能量原理的光顺方法能够方便地控制目标曲面的精度和边界条件，从而能够实现曲面模型的全局连续性，但是能量法的运算速度还有待提高；刚度调整法实现简单，但是生成的曲面的可编辑性较差；小波分解方法计算速度很快，能够有效地实现数据压缩，但是其逼近误差和边界条件却难于控制。 |
| 9. | Then a high - degree geometric continuity blending surface is obtained with transfinite interpolate method . ( e ) g3 blending surface with approximation can be constructed by lofting if geometric invariant errors are given , the surface can be converted to b - spline , nurbs form for the purpose of system aggregation
最后，为满足曲面造型系统集成的需要，在保证曲率、曲率导数和挠率精度情况下，将上述研究结果应用于曲面放样逼近方法，得到参数过渡曲面转换成b样条曲面或nurbs曲面的形式。 |
