简介:AnewmethodisproposedforsurfaceconstructiononirregularquadmeshesasextensionstouniformB-splinesurfaces.Givenanumberofcontrolpoints,whichformaregularorirregularquadmesh,aweightfunctionisconstructedforeachcontrolpoint.TheweightfunctionisdefinedonalocaldomainandisC1continuous.Thenthewholesurfaceisconstructedbytheweightedcombinationofallthecontrolpoints.ThepropertyofthenewmethodisthatthesurfaceisdefinedbypiecewiseC1bi-cubicrationalparametricpolynomialwitheachquadface.ItisanextensiontouniformB-splinesurfacesinthesensethatitsdefinitionisananalogyoftheB-splinesurface,anditproducesauniformbi-cubicB-splinesurfaceifthecontrolmeshisaregularquadmesh.Examplesproducedbythenewmethodarealsoincluded.
简介:Inthispaper,thesmoothconnectionbetweentwoB-splinesurfacesisdiscussed.First,abriefproofofsomesimplesufficientconditionsofG~0andG~1continuityisgiven.Onthisbasis,anovelmethodforG~0orG~1connectionbetweentwoadjacentB-splinesurfacesispresented.Areparameterizationstepisfirstlytakenforoneofthesurfacessuchthattheyhavethesameparameterizationinvdirection,then,adjusttheirboundarycontrolverticestomakethemG~0orG~1connected.TheG~1connectionparameterisdeterminedbyanoptimizationproblem.Comparedwiththeexistedmethods,ourmethodissimpleandeasytobeusedinpractice.