帶多幾何參數(shù)的細分造型方法研究.pdf

1、中南大學(xué)碩士學(xué)位論文帶多幾何參數(shù)的細分造型方法研究姓名：丘夏申請學(xué)位級別：碩士專業(yè)：計算機軟件與理論指導(dǎo)教師：趙歡喜20090519ABSTRACTSubdivisioniSoneimportanttechnologyincurvesandsurfacesmodeling，andsubdivisionhasbeenwidelyusedinComputerAidedGeometricDesignandComputerGraphicsAcl

2、assofsubdivisionschemeswithmulti。geometricparametersiSdiscussedinthisthesisComparedwiththeotherexistingmethods，theproposedschemescanexactlyreproduceconicsectionarcsofarbitrarylength，andcreateav撕etyofshapelikebumpsandfiat

3、edgesAndinthisthesiswealsoproposeanewsubdivisionschemewhichiSdifferentfromthetraditionalinterpolatingsubdivisionschemeinwhichallthepointsateachrefinementlevelarechangedbutinourschemethegeneratedlimitcurveonlypassesthroug

4、htheinitialdatapointsThenumericalexperimentsshowourapproachcombinestheadvantagesofapproximatingschemeswiththeprecisecontrolofinterpolatingschemesThisthesisiSstructuredasfollows：Firstofa11athree—pointschemewitha10caltensi

5、onparameteralocalbiasparameterandaglobaltensionparametertocontrolthetightnessandoffsetofthelimitcurve，respectivelyBychoosingappropriateparameters，thesubdivisionschemeisshape—preserving，suchas，flatedgespreserving，convexit

6、y—preservingAndthenweproposeanonstationarysubdivisionschemecanreproducecirclesorconicsectionsbychoosingappropriateparametersAtlast，inthisarticleweproposetwofourpointinterpolatingsubdivisionschemeswhichiSdesignedintraditi

7、onalwayFirstlyastationarysubdivisionschemewhichwithaglobaltensionparameterandalocalbiasparameteriSpresentedFurthermore，basedonthestationarysubdivisionscheme，weproposeanonstationarysubdivisionscheme，whichiSmuchmoresmoothK