云的模拟技术综述

:2008206229;:2008208224:(60473141);(20062191);CAD&CG:(19822),,,,([e-mail]);(19672),,,,,;(19642),,,,,;(19822),,,,.31a,2,1a,1b(1.a.;b.,233012;2.,116018):,,,,,,,:;;;;:TP301.6:A:100123695(2009)0421205205CloudsimulationtechniquereviewWUJing1a,XUXiao2gang2,CHENXin2lai1a,MAOMing1b(1.a.Dept.ofInformationTechnology,b.Dept.ofElectromechanical,BengbuNavalPettyOfficerAcademy,BengbuAnhui233012,China;2.Dept.ofAutomatization,DalianNavalAcademy,DalianLiaoning116018,China)Abstract:Cloudisanaturalphenomenonexistedhereandthere.Foritsspecialcharacterinnodefinitesurface,nodefiniteboundary,andtime2changingshape,cloudrenderingisregardedasoneofthemostchallengesubjectincomputergraphics.Cloudsimulationhasgreatpotentialapplications,suchastheflightsimulation,movie,andvirtualbattlefieldetc.Thispaperdescribedanoverviewofthealgorithmaboutcloudrenderingfromshape,dynamiccharacterandlightscatteringeffectaspect.Furthermore,analyzedseveraltypicalapproachesindetail.Finally,discussedtheexistedproblemsandfuturework.Keywords:cloud;real2time;simulation;particlesystem;voxelvolumes,,,,,,,,,,,;,,,,,Harris[1,2];Umen2hoffer[3]particleblocksdepthimpostors,Wang[4],Do2bashi[5,6],Splatting,,,,:a),;b),;c)1,,,,:a)(particlesystem)Reeves[7]1983,26420094ApplicationResearchofComputersVol.26No.4Apr.2009,,,;,b)MetaballMetaballMetaball,Splatting:1996Nishita[8]Me2taball,MetaballMetaball1998Dobashi[9]Metaball,c)(voxelvolumes),,,[10,11],1984Kajiya[12],,;Dobashi[5,6](cellularautomata),Splatting;2002Overby[13];2003Harris[1],,d)(proceduralnoise),,Perlin,Ebert[1416],,,,Schpok[17]EbertGPU,e)TexturedSolids,[1820]Gardner[18],2001Elinas[19],,Vane[21],Perlin,,,f),,Roett2ger[22],,,,,Metaball,1,,,,Kajiya[12]1984,Navier2StrokesVAX11/78010102010s,1s2002Overby[13],,Stam[23]Navier2Strokes,800MHzPentium3,1550152003Harris[1],,,Mizuno[24]2FM(2fluidsmodel),2002Miyazaki[25]computationalfluiddynamics,,,Neyret[26],Dobashi[6]Nagel,500MHzPentium3,015s25625620[6],Miyazaki[27]coupledmaplat2tices(CML)CML,MiyazakiCML,,1GHzPentium3,2562564035s,10s,,(GPU),[1,17,28],1,,1982,Blinn[29],,,602126(singlescattering),,;,(multiplescattering),,,:a)SphericalharmonicsSphericalharmonics,sphericalhar2monics[12,30].1995JosStamKajiyasphericalharmonicsn,,,,[12]Kajiya,,:(a),multigridmethod;(b)b):,,,,1987Rushmeier[31],,(zonalmethod),,,,1996Nishita[8],,,,:(a),,;(b)c)DiscreteordinatesM,1994Max[32],,Max,,,d),,,,,(importancesampling),,,,Blasi[33],,,,,,,Nishita[8]referencepatternPhotonmapping,,photonmap,,[34]Photonmapping,JensenChristensenphotonmapping,e),Kajiya[12],,Harris[1]2000Dobashi[5],OpenGLAPIstexturedbillboards,,,,[5]2001Harris[2],Kniss[11](half2angleslicing),,,Dobas2hi,,,Riley[35,36],f),2003Wang[4],:,,;,,,,;,,70214,:,,[4],:;,;,;1,1),,;,,16km220200,,,,,1100,,,,,,,2),billboard,,,,,,1:a),,;,,b),;,,1,:a),,,,,,,,,,b),,,;,,,,,;,1,,,,,,,,131Reeves[7]Nishita[8]MetaballKajiya[12]Ebert[14,15]Elinas[19]Roettger[22]2Overby[13]Harris[1]Bouthors[20]Dobashi[6]Miyazaki[27]CML3Kajiya[12]Nishita[8]Blasi[33]Dobashi[5]Wang[4],:802126;;,,GPU[1,28];;;:a),[1,3,4],,,,b),,,,c),,d),,,,,e)GPU,,:[1]HARRISMJ,BAXTERWV,SCHEUERMANNNT,etal.Simula2tionofdynamicsongraphicshardware[C]//ProcofACMSIG2GRAPH/EUROGRAPHICSConferenceonGraphicsHardware.2003:922101.[2]HARRISMJ.Real2timecloudrendering[C]//ProcofEUROGRAPH2ICS.2001:76284.[3]UMENHOFFERT,SZIRMAY2KALOSL.Real2timerenderingofcloudynaturalphenomenawithhierarchicaldepthimpostors[C]//ProcofEUROGRAPHICS.2005.[4]WANGN.Realisticandfastcloudrenderin[C]//ProcofSIGGRAPH.2003.[5]DOBASHIY,KANEDAK,YAMASHITAH,etal.Asimple,effi2cientmethodforrealisticanimationofclouds[C]//Procofthe27thAnnualconferenceonComputerGraphicsandInteractiveTechniques.2000.[6]DOBASHIY,NISHITAT,OKITAT.Animationofcloudsusingcel2lularautomation[C]//ProcofComputerGraphicsandImagingCon2ference.1998:2512256.[7]REEVESWT.Particlesystems:atechniqueformodelingaclassoffuzzyobjects[J].ACMTransonGraphics,1983,2(2):912108.[8]NISHITAT,DOBASHIY,NAKAMAEE.Displayofcloudstakingintoaccountmultipleanisotropicscatteringandsky[C]//ProcofSIG2GRAPH96.1996:3792386.[9]DOBASHIY,NISHITAT,YAMASHITAH,etal.UsingMetaballstomodelingandanimatecloudsfromsatelliteimage[J].TheVisualComputer,1998,15(9):4712482.[10]WESTOVERL.Footprintevaluationforvolumerendering[C]//ProcofSIGGRAPH.1990:3672376.[11]KNISSJ,PREM8ZES,HANSENC,etal.Interactivetranslucentvolumerenderingandproceduralmodeling[C]//ProcofIEEEVisua2lization.2002:1092116.[12]KAJIYAJT,VonHERZENBP.Raytracingvolumedensities[J].ComputerGraphics,1984,18(3):1652174.[13]OVERBYDR.Interactivephysically2basedcloudsimulation[C]//Procofthe10thPacificConferenceonComputerGraphicsandAppli2cations.2002:4692470.[14]EBERTDS,PARENTRE.Renderingandanimationofgaseousphenomenabycombiningfastvolumeandscanlinea2buffertechniques[J].ComputerGraphics,1990,24(4):3572366.[15]EBERTDS.Volumetricmodelingwithimplicitfunctions:acloudisborn[C]//ProcofSIGGRAPH97.1997.[16]EBERTDS.Interactivecloudmodelingandphotorealisticatmosphe2ricrendering[C]//ProcofSIGGRAPH.2004:2382256.[17]SCHPOKJ,SIMONSJ,EBERTDS,etal.Areal2timecloudmode2ling,rendering,andanimation