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1、Compositing3DImageswithAntialiasingandVariousShadingEffectsEihachiroNakamaeHiroshimaUniversityTakaoIshizakiDaikinIndustries,Ltd.TomoyukiNishitaFukuyamaUniversityShinichiTakitaKagawaUniversityAdvancesin3Drenderingtechniqueshavegivenriseandastheamountofdatabecomeslarge,itbecomestoavar
2、ietyofgeometricmodelsandshadingmodels:troublesometocheck.Subdividingtheprocessingsothatpolygonalobjects,curvedsurfaces,andfractalfaces,itisperformedbyacollectionofseparateprogramscanreflection,refraction,transparency,texturemapping,leadtoamoreflexibleandmoreeasilymaintainedbump-mapp
3、ing,fogeffect,andvarioustypesoflightsystem.sources.ToprocessallthesemodelsinasingleprogramToaddressthisproblem,WhittedandWeimer’pro-isusuallydifficult.Thatis,theprogrambecomeslargeposedaflexiblescan-conversionprocessorthatcanandcomplex,itrequirestremendoustimetodevelop,simultaneousl
4、ydisplayseveraldifferentsurfacetypesonMarchISRS0272.1716/89/0300-0021$01.001989IEEE:!1capabilitiesinadditiontothoseavailableinpreviouslydevelopedsystems:1.Antialiasedimageswithscaling:Zoomingissome-timesusedinanimation.InCADsystems,scalingofdo=116ageneratedimageisusefulfordisplaying
5、detailsofshapes.Forshapedesign,independentstretchingind,=1/3theverticalandhorizontaldirectionsisuseful.alscanlineTherefore,itisdesirablenotonlytocomposited,=1/3imagesbuttobeabletoscalethecompositedimages.d,=1/6Whitted’smethoddisplayshigh-qualityimagesbyusinganantialiasingtilersuchas
6、Catmull’s,’buttheantialiasingprocessiscomplicated.Methodsuiingalpha-channelaresimplebecauseofthepixel-by-pixelnatureoftheprocessing.However,noneofthesemethodscancompositeimageswithscaling.Figure1.DensitycalculationforpixelABDC,usingInthisarticleweperformantialiasingbasedonthethemult
7、iscanningmethod.multiscanningmethod,’withvisiblefacesstoredforeachsub-scanline.Thatis,sufficientdataisstoredtodisplayantialiasedimageswitharbitraryscalingfactors.2.Varietyoflightsources:Forlightingdesign,itisanimage.Thisisdesignedtobea“test-bed”thatcaneas-necessarytodisplaymanytypes
8、oflightsourcesinily
