Some different method is used to fulfill the bezier and nurbs surface fitting
This thesis studies the problems of geometric continuity in nurbs surfaces reconstruction
These results are more useful to improve the smoothness of nurbs models
The main algorithms are applied in the practical system - and received sound effects
Secondly , the genetic algorithm is employed to calculate the minimum distance between two general nurbs surfaces
Most importantly , it brings together all these techniques in an effective procedure automatically reconstruct nurbs surfaces of arbitrary topological type
In this paper we also present a procedure for automatically reconstructing a nurbs surface of arbitrary topological type from an unorganized set of points
Since a single nurbs patch can only represent surfaces of simple topological type , a complex product surface must be defined as a network of nurbs patchs
The object ' s surface often possesses some particular continuities , so it is indispensable to be able to control the desired continuities between adjacent nurbs patches
The problems on parameterization of implicit algebraic surfaces and inversion of parametric surfaces are discussed and the inversion equations for some nurbs surfaces are derived in detail
用nurbs曲面造句挺难的，這是一个万能造句的方法
Firstly , based upon the technique of splitting the nurbs surfaces and bounding containers , a split algorithm is applied to calculate the minimum distance between two general nurbs surfaces
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
Secondly , based on nurbs curves approximation algorithm , a nurbs surface approximation algorithm on discrete data sets is given . thirdly , a shape - preserving parametric surface interpolation to data set is given
This makes it possible to approach the global optimal value with less number of units . in comparison with the standard genetic algorithm , this enhanced genetic algorithm is more quickly and reliably
This thesis , from different analytical points of view , proposes three algorithms for the minimum distances between convex nurbs surfaces and general nurbs surfaces respectively
Another important achievement of thesis work is a nurbs curve ans surface display software based on microsoft windows . it adapts object based programming ( obp ) conception and has lots of interactive function
To the bezier surface fitting , skimming is used after the cross - section line is fitted . optimal design is brought to the modeling of nurbs surfaces to resolve practical problems . lastly taking a specific example in this paper
The paper studies the smoothness and fairness of nurbs curves and surfaces , gives a practical and efficient global fairing method of nurbs curves , then introduces the criterion of minimum energy to deal with the smoothness of nurbs surfaces
In the fields of reserve engineering , cad / cam , computer aided geometric design , computer graphics , etc . , the key problems are the reconstruction of complicated surfaces and the standard tools are nurbs curves and surfaces
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
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