简介:RationalBéziersurfaceisawidelyusedsurfacefittingtoolinCAD.WhenalltheweightsofarationalBéziersurfacegotoinfinityintheformofpowerfunction,thelimitofsurfaceistheregularcontrolsurfaceinducedbysomeliftingfunction,whichiscalledtoricdegenerationsofrationalBéziersurfaces.Inthispaper,westudyonthedegenerationsoftherationalBéziersurfacewithweightsintheexponentialfunctionandindicatethedifferenceofourresultandtheworkofGarc′?a-Puenteetal.Throughthetransformationofweightsintheformofexponentialfunctionandpowerfunction,theregularcontrolsurfaceofrationalBéziersurfacewithweightsintheexponentialfunctionisdefined,whichisjustthelimitofthesurface.Comparedwiththepowerfunction,theexponentialfunctionapproachesinfinityfaster,whichleadstosurfacewiththeweightsintheformofexponentialfunctiondegeneratesfaster.
简介:传统的建模方法不能精确表示曲面体的弯曲度,针对这些不足,本文采用有理Bezier方法构建曲面模型,给出了椭球体标准型有理二次Bezier控制点和权因子的求解算法;利用非有理Bezier的升阶算法将有理二次Bezier升阶为有理三次Bezier,给出了标准型有理三次Bezier曲线控制点和权因子的求解算法,构建了有理双三次Bezier椭球体曲面模型,通过调整控制点或权因子参数可生成如葫芦、青椒、鸡蛋等光滑的曲面模型.实验表明,该算法具有很好的设计灵活性和交互性,为构建曲面模型提供了新的技术支持.
简介:摘要在地铁线路中,小半径曲线是经常发生病害的地段,如果没有做好适当处理,将可能因此导致安全隐患的出现。对此,在本文中对地铁小半径曲线轨道常见病害进行分析,并对地铁小半径曲线养护与维修进行一定的研究。