Study And Realize On Fairing And Smooth Joining Between Adjacent Of Bicubic Nurbs Surface

Along with the rapid improvement of modern industry and Sci-Tech, modeling technology of curve and surface are becoming more and more maturity. Non Uniform Rational B-Spline (NURBS) is becoming the most outlooks modeling technology. It has been specified as a standard of industrial products geometry description method and has been widely used and recommended.In this paper, the fairing and smoothing joining between adjacent of bicubic NURBS surfaces are studied. The main content of this paper includes the following four parts,⑴the joining between adjacent of bicubic NURBS surfaces,⑵the fairing and smoothing of bicubic NURBS surfaces,⑶the construction of interactive CAGD system based on GLUT.In the first part - the chapter 3, Joining between two bicubic NURBS surfaces which have the same boundary are studied, and a useful algorithm which satisfy G1 connectivity is introduced. Although it's based on bicubic NURBS surface, it can be easily improved to high degree which can be used widely. The algorithm is simplicity and rapidly for calculations. The realistic experiment data and the theory are referenced. An effective method of G1 connectivity of three bicubic NURBS surfaces which have the same corner is obtained. It also references the method of two NURBS surfaces joining and based on space projection of control points. It can be proved that all algorithms are feasible.In the part two - chapter 4, Focus on the boundary after the surfaces had been jointed. The curvature mapping and the line-frame map of the surfaces are produced. In terms of them the smoothing attributes of boundary is analyzed. It's explicitly, effective and subjective. As for the objective detection of smoothing, the shearing force degree is used to detect the bad point, which is known as the non-smoothing point, and a smoothing way based on it is introduced. The surface can be smoothed by means of changing the value of weight which near the bad point.The third part of paper - chapter 5, a CAGD graphic system is constructed by using GLUT. It is useful and simply, at the same time it can be merged between different computer systems. And it can be flexibly enlarged and enhanced. Each layer of system is seamless.The main conclusions of the dissertation are given in the last chapter, in addition to direction of next researches.