简介:AnewmethodtotheproblemoffairingplanarcubicB-splinecurvesisintroducedinthispaper.Themethodisbasedonweightedprogressiveiterativeapproximation(WPIAforshort)andconsistsoffollowingsteps:findingthebadpointwhichneedstofair,deletingthebadpoint,re-insertinganewdatapointtokeepthestructureofthecurveandapplyingWPIAmethodwiththenewsetofthedatapointstoobtainthefairedcurve.Thenewsetofthedatapointsisformedbytherestoftheoriginaldatapointsandthenewinsertedpoint.Themethodcanbeusedforshapedesignanddataprocessing.Numericalexamplesareprovidedtodemonstratetheeffectivenessofthemethod.
简介:Inthispaper,wepresentanalgorithmforreconstructionofB-splinesurfacesuchthatitinterpolatesthefourgivenboundarycurvesandsimultaneouslyapproximatessomegiveninnerpoints.Themainideaofourmethodis:first,weconstructaninitialsurfacewhichinterpolatesthefourgivenboundarycurves;then,whilekeepingtheboundarycontrolpointsoftheinitialsurfaceunchanged,werepositiontheinnercontrolpointsofthesurfacewithenergyoptimizationmethod.Examplesshowthatouralgorithmispracticableandeffective.
简介:Resortingtocubicsplinefunctioninsteadofparametricsplinerepresentation,anexplicitfairnessindicatorandanefficientfairingalgorithmfor2Dcurvesarepresented.Theinputpointsequenceisfirstlypartitionedintoseveraloverlappedfunctionsegments.Foreachsegment,acubicsplinefunctionisusedastherepresentationtoolwhichentailsapolylineapproximationofcurvatureplot.Basedontheextrinsicrelationshipbetweenthepolylineandthepositionsofdatapoints,acoarse-to-finefaringmethodisproposedwhichefficientlyidentifiesandeliminatestheunnecessaryinflectionpoints.Ouralgorithmgeneratesthebestresultstodate,whichisvalidatedbynumerouspracticalexamples.