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本科生毕业设计（论文）第1页翻译部分英文原文SKETCHINGANDDIRECTCADMODELLINGINAUTOMOTIVEDESIGNMICHAELTOVEYANDJOHNOWENCOVENTRYSCHOOLOFARTANDDESIGN,COVENTRYUNIVERSITY,PRIORYSTREET,COVENTRYCV15FB,UKACCEPTED13MAY1999AVAILABLEONLINE30NOVEMBER2000ABSTRACTTHISPAPEREXAMINESTWOMETHODSOFCOMPUTERBASEDCARSTYLINGTEXTUREMAPPINGANDDIRECTCOMPUTERMODELLINGANOVERVIEWOFCURRENTACTIVITYINTHEFIELDPRECEDESACOMPARISONANDEVALUATIONOFTHEMETHODSWITHINATYPICALFRAMEWORKFORAUTOMOBILECONCEPTDESIGNTHREECASESTUDIESILLUSTRATETHEDIRECTMODELLINGMETHOD,SHOWINGDIFFERENCESOFCOMPUTERUSEINEACHCASEFURTHERDEVELOPMENTSOFTEXTUREMAPPINGAREREPORTED,WITHAPROPOSALFORITERATIVECOMBININGOFTEXTUREMAPPINGANDDIRECTMODELLINGAUTHORKEYWORDSCOMPUTERAIDEDDESIGNSTYLINGAUTOMOTIVEDESIGNACKNOWLEDGEMENTSREFERENCESMOSTSTAGESOFTHEAUTOMOTIVEDESIGNPROCESSUSECOMPUTERAIDEDDESIGNTOSOMEDEGREE,ANDSOMENOWRELYWHOLLYONITINCONCEPTDESIGN,HOWEVER,ATTHESTARTOFTHEPROCESS,THEREISRELUCTANCETOCOMMITWHOLEHEARTEDLYTOCOMPUTERUSEDESIGNSTUDIOSTHATDOUSECOMPUTERSINCONCEPTDESIGNDIFFERINHOWTHEYUSETHEMSOMEALLOWSTYLISTSTOMODELDIRECTLYUSINGCAD,ANDOTHERSONLYUSEELECTRONICPAINTBOXSYSTEMSFORSKETCHINGREASONSFORTHISRELUCTANCEAREOBVIOUSCONCEPTDESIGNDEPENDSONRAPIDPRODUCTIONOFDESIGNIDEAS,USUALLYINTHEFORMOFSKETCHES,ANDMOSTCADTECHNIQUESARECOMPARATIVELYTIMECONSUMINGVANDIJK1ASSERTSTHATTHEREARECURRENTLYNOCADSYSTEMSTHATLIVEUPTOTHEREQUIREMENTSOFCONCEPTDESIGNMANYCOMMERCIALSOFTWAREPRODUCERSANDRESEARCHERSHAVEATTEMPTEDTOREMEDYTHATTHISPAPEREXAMINESWHETHERCOMBININGSKETCHESWITHCOMPUTERMODELSMADEBYASTYLISTCOULDQUICKLYPROVIDEANAPPROPRIATESOLIDMODELASPARTOFTHECONCEPTDESIGNSTAGE1CURRENTDESIGNPROCESSESINTHECARINDUSTRYTHEINDUSTRYISLARGE,HIGHLYSTRUCTURED,ANDTRADITIONALLYMINDEDMANYLONGESTABLISHEDDECISIONMAKINGMETHODSARESTILLCONSIDEREDVALIDCRUCIALLY,THEHANDOVERFROMSTYLISTTO本科生毕业设计（论文）第2页ENGINEERISSEENASANIMPORTANTDEMARCATIONBECAUSEPRODUCTDEVELOPMENTREQUIRESHIGHLEVELSOFINVESTMENT,DESIGNCHANGESTENDTOBEEVOLUTIONARY,WITHNEWMODELSDEVELOPEDFROMCURRENTONESTHISALLOWSSPECIALISATIONWITHINDESIGNTEAMSANDDEMARCATIONBETWEENVARIOUSTYPESOFSTYLISTANDENGINEERTOPERSISTINTHETRADITIONALPROCESSA3DMODEL,FULLYPAINTEDANDSHOWINGGENERALSURFACES,ISCONSIDEREDVITALINDETERMININGWHICHCONCEPTSAREWORTHDEVELOPMENT,ANDASMALLNUMBEROFQUARTERSCALEMODELSAREMADEBYCLAYMODELLERSTOSUPPORTTHIS11HISTORICALOVERVIEWOFDESIGNCONVENTIONALLY,THEAUTOMOTIVEDESIGNPROCESSISSTRUCTUREDTOEMPHASISETHEDEMARCATIONBETWEENSTYLINGANDENGINEERINGSTYLISTSARERESPONSIBLEFOR,ANDCONTROL,THEEARLYSTAGESOFTHEPROCESSANDTHENHANDOVERTHEDESIGNTOENGINEERSFORANALYSISANDMAKINGITREADYFORPRODUCTIONTHESTRUCTUREOFTHESTYLINGPHASEISMOSTEASILYDESCRIBEDASITEXISTEDBEFORETHEINTRODUCTIONOFCADDESIGNSTUDIOSEMPLOYDIFFERINGAPPROACHESTOTHECONCEPTDESIGNPHASE,BUTATYPICALARRANGEMENTISSHOWNINTABLE1,ASDESCRIBEDINTOVEY2TABLE1THESTAGESOFTHESTYLINGPROCESSVIEWWITHINARTICLE12COMPUTERUSEINDESIGNTHESTYLINGPROCESSFALLSNATURALLYINTOTWOPARTSCONCEPTDESIGNUPTOWEEK4ANDDESIGNDEVELOPMENTTHEREAFTERCOMPUTERSTENDTOBEUSEDMOREASSTYLINGPROCEEDS,WITHGREATESTUSEAFTERWEEK7SURFACEPROVINGANDFINITEELEMENTANALYSISARETYPICALAREASWHERECOMPUTERASSISTANCEISALREADYWELLDEVELOPEDANDISUNDERFURTHERDEVELOPMENTDESIGNDEVELOPMENTISAMORECONSIDEREDPROCESSWITHTHEDESIGNLESSSUBJECTTORADICALCHANGETHANINCONCEPTDESIGNWHERERAPIDCHANGESAREFREELYTOLERATEDITISCONCERNEDWITHOPTIMISATIONANDCONFORMITYTOENGINEERINGANDERGONOMICPRINCIPLESINIT,DESIGNCONCEPTSDEVELOPFROMILLDEFINEDPROPOSALSTOFULLYDETAILEDDESIGNS,ANDARETHENHANDEDOVERTOENGINEERSTHISSTAGEISINCREASINGLYSUPPORTEDBYCADTECHNIQUES13CADFORSTYLISTSSEVERALATTEMPTSATCOMPUTERAIDEDCONCEPTDESIGNHAVEBEENMADEINDEPENDENTLYOFCOMMERCIAL本科生毕业设计（论文）第3页SOFTWAREPROVIDERSVANDIJK1DEVELOPEDAFASTSHAPEDESIGNPROTOTYPETOINTRODUCEDESIGNERSTOCOMPUTERAIDEDCONCEPTDESIGNTHISCONCENTRATESONPROVIDINGTOOLSFORDESIGNERSTHATRESEMBLECONVENTIONAL2DDRAWINGUSINGINPUTDEVICESTHATMIMICHANDMOVEMENT,USERSAREABLETOREVIEWALTERNATIVECONCEPTSANDTOSWITCHBETWEENVIEWSOFTHEMTHEDESIGNERSKETCHESCURVESONTOAPERSPECTIVEPLANE,ORBRINGSTHEMINFROMALIBRARY,ANDMANIPULATESTHEMINTO3DPOSITIONSURFACESARETHENQUICKLYBUILTBETWEENTHEMMODIFYINGACURVEUPDATESTHESURFACESATTACHEDTOITMOSTOFTHEDESIGNERSWHOUSEDTHISPROTOTYPESAIDTHATITCOULDHELPTHEIRCONCEPTDESIGNPROCESS,THOUGHITNEEDEDFURTHERREFINEMENTVANELSASANDVERGEEST3DESCRIBEAPROGRAMFORQUICKLYCREATINGDETAILFEATURESFROMANEXISTINGSURFACEBYDISPLACINGACONSTRAINEDPORTIONOFITTHEIRINTENTIONWASTOENABLEDESIGNERSTOALTERQUICKLYGENERATEDSURFACESBYDRAWINGCURVESDIRECTLYONTOTHEMANDCONSTRUCTINGEITHERDEPRESSIONSORPROTRUSIONSBYDEFORMINGTHESURFACEWITHTHECURVEDISPLACEMENTSMADEINTHISWAYHAVEFLATTOPSPARALLELTOTHESURFACE,WITHAZONEOFTRANSITIONROUNDINGOFFTHEFORMTHEIRPROTOTYPEINTERFACEUSESSLIDINGCONTROLSTOVARYTHEDISPLACEMENTCHARACTERISTICSTHECURRENTAUTHORSHAVEALSOWORKEDONRAPIDSHAPECREATIONSEEOWEN,TOVEYANDDEKKER4,WHEREAGREYSCALEIMAGEGENERATESCONTINUOUSVARIATIONINDISPLACEMENTOFTHESURFACEMOTORCARFORMSANDHUMANFACESHAVEBEENRAPIDLYPRODUCEDINTHISWAYALTHOUGHCARSCANBEMODELLEDQUICKLYBYAPPLYINGASIMPLIFIEDANDLOCALLYSHADEDCUTOUTIMAGETOASURFACE,ITISHARDERTOSHADEADEPTHMAPFORFACESRESEARCHTODETERMINEIFSTYLISTSCANHANDSHADEACCURATELYENOUGHFORDISPLACINGAVEHICLESURFACEISPLANNEDDEPTHMAPPEDSURFACESAREALSOUSABLEASBASEMODELSFORTEXTUREMAPPING,ASDESCRIBEDLATERINTHISPAPERFIG1ANDFIG2FIG1SURFACEGENERATEDBYDISPLACEMENTMAPPINGAGREYSCALEIMAGEONTOAPLANESURFACEVIEWWITHINARTICLEFIG2TEXTUREMAPPEDFACEREPRESENTATIONSVIEWWITHINARTICLE本科生毕业设计（论文）第4页HUMMELSANDOVERBEEKE5DEVELOPEDCOMPUTERMODELLINGTOOLSFORATWOHANDEDGESTUREBASEDCARSTYLINGMETHODTHESTYLISTWEARSONEACHHANDGLOVESCONNECTEDTOAVIRTUALSPACEHANDMOVEMENTSSKETCHOUTSURFACESINTHEVIRTUALSPACEVARYINGTENSIONINTHEHANDMOVEMENTSCONTROLSTHEINTENSITY,ANDTHUSTHECOMMITTEDNESS,OFTHEFORMADDINGCALIBRATEDFEEDBACKWITHADAMPEDANDSPRUNGDEVICESIMILARTOTHATDESCRIBEDBYGALYEANANDHUGHES6MAYBEOFBENEFITHEREAVOXELMODELISSHAPEDUSINGFORCEFEEDBACKARRAYSAROUNDAFREEMOVINGPOLHEMUSISOTRAKDEVICETHEISOTRAK,WHICHPROVIDESCONSTANTPOSITIONALINFORMATION,ISSUSPENDEDBYEIGHTELASTICBANDSWITHINACUBESOTHATRESISTANCECANBEFELTWHILEMOVINGINSPACEANDINTOTHEVIRTUALVOXELSRELATEDWORKINCLUDESOVERBEEKE,KEHLER,HUMMELSANDSTAPPERS7,ANDDIJK,VERGEESTANDHORVTH82CONCEPTMODELLINGWHETHERCONCEPTDESIGNSHOULDBECADBASEDISANOTHERMATTERTOVEY9IDENTIFIESTHEPRESENTATIONREQUIREMENTSOFCONCEPTDESIGN,WHICHISTHEINFORMATIONTHATTHEMANAGEMENTPROCESSUSESTOTAKETHEDESIGNFURTHERTHISINFORMATIONISPROVIDEDINTWOWAYSADISPLAYOFTWOA0SIZEDILLUSTRATIONSOFTHEDESIGNINFLUENCES,ANDADISPLAYOFUPTOFIFTYA3ORA4CONCEPTSKETCHESTHEREAREATLEASTTWOPROBLEMSTHATTHISCAUSESWITHATTEMPTSTOUSECOMPUTERSFORCONCEPTDESIGNFIRSTLY,COMPUTERDRAWINGANDPAINTINGPACKAGESLACKTHEFLUENCYOFPAPER,PENCILANDPASTELTOWHICHSTYLISTSAREACCUSTOMEDTHISGREATLYSLOWSTHEEASEANDSPEEDWITHWHICHSKETCHESCANBECREATEDSECONDLY,THELIMITEDSIZEANDRESOLUTIONOFCOMPUTERDISPLAYSPERMITSFARFEWERTHANFIFTYIMAGESTOBEDISPLAYEDSIMULTANEOUSLYWITHANYDEGREEOFFIDELITYWHILEDEVELOPMENTSINBOTHSOFTWAREANDHARDWAREPROCEED,ITISHARDTOIMAGINETHATTHESEPROBLEMSWILLBEOVERCOMEINTHENEARFUTUREGIVENTHESELIMITATIONS,INWHATWAYSMAYCADBEUSEFULFORCONCEPTDESIGNONEREASONFORUSINGCADISCOMPUTERMODELLINGDESPITETHEIMPORTANCEOFSKETCHESTOCONCEPTDESIGN,THEYARETWODIMENSIONALREPRESENTATIONSOFWHATISHOPEDWILLBECOMETHREEDIMENSIONALFORMSINTHETRADITIONALSTYLINGPROCESS,ATHREEDIMENSIONALVISUALISATIONOFADESIGNISUNAVAILABLEUNTILATLEASTWEEK3,WHENAROUGHCLAYORFOAMMODELMAYHAVEBEENMADEPRODUCTIONOFEVENSUCHROUGHMODELSISRELATIVELYEXPENSIVEANDTIMECONSUMING,LIMITINGTHENUMBEROFDESIGNCONCEPTSTHATCANBEVISUALISEDIFASKETCHORSETOFSKETCHESCOULDBETURNEDQUICKLYINTOA3DCADMODEL,THISNUMBERMAYINCREASEDRAMATICALLYOURINTENTIONINTHISPAPERISTODESCRIBETWOMETHODSFORPRODUCINGEVALUABLECONCEPTMODELSBASEDONSKETCHES,ANDTOSHOWHOWTHEYCONFORMTOMANAGEMENTDECISIONREQUIREMENTSTHESEMETHODSAREFIRSTLY,DIRECTMODELLING,ORWORKINGDIRECTLYFROMINITIALCONCEPTSKETCHESTOPRODUCE3DCOMPUTERMODELSANDSECONDLY,SKETCHMAPPING,ORATTACHINGCONCEPTSKETCHESTO本科生毕业设计（论文）第5页SIMPLECADMODELSTOPRODUCE3DIMENSIONALSKETCHESWETHENPROPOSEAHYBRIDMETHODTHATALLOWSTHESTYLISTARANGEOFPOSSIBLEOUTCOMES21DIRECTMODELLINGFROMCONCEPTSKETCHESWEREPORTHERETHREECASESTUDIESOFSTUDENTSONTHEBATRANSPORTDESIGNCOURSEATCOVENTRYUNIVERSITYALLSHOWTHEDIRECTCOMPUTERMODELLINGMETHOD,THOUGHEACHAPPROACHESITDIFFERENTLYALLTHREESTUDENTSHADUSEDTHEALIAS|WAVEFRONTMODELLERBEFORETHEIRPROJECTTWOSTUDIEDPARTTIMEWHILECONTINUINGTOWORKINSTYLINGSTUDIOSNEARCOVENTRYTHETHIRDWASAFULLTIMESTUDENTBOTHTHEPARTTIMERSWERETRAINEDAUTOMOTIVECLAYMODELLERSWITHFOURTEENYEARSEXPERIENCEBETWEENTHEMTHEFULLTIMESTUDENTHADWORKEDINASTYLINGSTUDIOONAPLACEMENTINTERNSHIPDURINGHISSTUDIESTHETECHNIQUESUSEDVARYFROMACOMPLETERELIANCEONTHESCREENIMAGETOASIMULTANEOUSCLAYANDCOMPUTERMODELAPPROACHINALLTHREECASES,ASTYLINGLINESMETHODWASUSEDFORCOMPUTERMODELCREATIONSEEOWEN,TOVEYANDDEKKER4BSPLINESAREPLACEDINTHETHREEORTHOGRAPHICWINDOWS,ANDMANIPULATEDUSINGCONTROLPOINTSTOPRODUCEANETWORKOFLINESINSPACETHESELINESREPRESENTMAJORVISUALCUESSUCHASSHUTLINESANDFEATURELINESSURFACESARETHENPRODUCEDBETWEENTHISNETWORKOFLINESANDCONSTRAINTSSUCHASCONTINUITY,TANGENCYANDIMPLIEDCURVATUREADDEDSUCHMODELSMAYBEUSEDASFINISHEDPRODUCTS,ORLINESFROMTHEEXISTINGNETORFROMPROJECTIONSONTOSURFACESCANBEUSEDASANUNDERLAYFORITERATEDDEVELOPMENT211CASE1ASIMULTANEOUSAPPROACHCOMPUTINGANDCLAYMODELLINGFACILITIESATTHEUNIVERSITYAREAVAILABLETHROUGHOUTTHEDAYTHEFIRSTSTUDENTCHOSETOMODELUSINGTHECOMPUTERDURINGTHEDAYANDUSINGCLAYINTHEEVENINGHETREATEDTHEMODELLINGPROCESSASAFULLYINTEGRATEDTASK,WITHDESIGNDECISIONSMADEINEITHERFORMATINFORMINGTHEWHOLEDEVELOPMENTHISEXPERIENCEOFBOTHCLAYANDCOMPUTERMODELLINGLEDDIRECTLYTOTHISWAYOFWORKINGHEBUILTONECLAYMODELANDARANGEOFCOMPUTERMODELSTHATDESCRIBEDTHEWHOLEFORMATFIRST,HISCONCEPTSKETCHINGTECHNIQUESSTRONGLYINFLUENCEDBOTHMODELTYPESHEMADEPAPERSKETCHESWITHMARKERSANDPASTELSANDELECTRONICSKETCHESWITHTHEALIAS|WAVEFRONTPAINTPACKAGELATERHEMADEADHOCREFINEMENTSTOTHECLAYANDCOMPUTERMODELSASTHEDESIGNDEVELOPEDHEBASEDBOTHMODELTYPESONHISSEATINGANDENGINEERINGPACKAGE,WHICHALSOINFORMEDTHEUNDERSTRUCTUREOFHISCLAYBUCKTHEOPENTOPPEDDESIGNMEANTTHATTHEBUCKHADTOACCOMMODATEAFULLYFORMEDINTERIOR,SOTHATBOTHINTERIORANDEXTERIORCOULDBESEENANDJUDGEDTOGETHERBECAUSEHEDEVELOPEDTHEDESIGNINTWOFORMATS,HECOULDUNDERTAKESOMENORMALLYTROUBLESOME本科生毕业设计（论文）第6页ASPECTSOFSURFACEPRODUCTIONTHATNORMALLYREQUIREMORETHANASTYLISTSLEVELOFUNDERSTANDINGHERESOLVEDEACHPROBLEMINTHEMOREAPPROPRIATEMEDIUM,ANDTHENAPPLIEDTHESOLUTIONINTHEOTHERASTIMEALLOWEDFOREXAMPLE,PROVINGCONTINUITYOVERADOUBLYCURVEDSURFACEISEASIERINCAD,BUTSURFACEINTERSECTIONANDRADIUSINGISMORESUITEDTOWORKINGINCLAYBECAUSEOFTACTILEFEEDBACKROUGHSOLUTIONSINCLAYCANBECROSSSECTIONEDANDREIMPORTEDTOCADFORSMOOTHINGFIG3ANDFIG4FIG3SNAPSHOTFROMCOMPUTER3DMODELINTHESIMULTANEOUSAPPROACHVIEWWITHINARTICLEFIG4PHOTOGRAPHOFFINISHEDMODELVIEWWITHINARTICLE212CASESTWOANDTHREEADIRECTMODELLINGBACKGROUNDBOTHSTUDENTSFOLLOWEDASPECIALLYORGANISEDPARTTIMEVERSIONOFTHECOURSEINCONJUNCTIONWITHTHEIREMPLOYERS,JAGUARANDROVERINTHISCOURSE,STUDENTSAREASKEDTOMAKEASMUCHUSEASPOSSIBLEOFTHEFACILITIESATTHEIRWORKPLACESBOTHOFTHEMHADACCESSTOADESIGNSTUDIO,ALIAS|WAVEFRONTSOFTWARE,ACLAYMODELLINGSTUDIO,3DMEASURINGEQUIPMENT,FIVEAXISMILLINGANDAFULLYWORKINGMODELSHOPDESPITETHEIRWORKINGINAPROFESSIONALENVIRONMENT,WEASSESSEDTHEIRWORKAGAINSTTHENORMALUNIVERSITYCOURSECRITERIA,TESTINGTHEIRABILITYTOTHINKACROSSPRACTICEDEMARCATIONSANDCONCEPTUALBARRIERSTHOUGHTHEYHADEXTENSIVEEXPERIENCEOFCLAYMODELLING,BOTHSTUDENTSINDEPENDENTLYEXPRESSEDINTERESTINCOMPUTERMODELLINGFORCAREERDEVELOPMENTANDFORTESTINGTHEIR3DTHINKINGSKILLSWITHINTHEIRPROJECTSTHEYFELTTHATBECAUSETHEIRSKILLSEXCEEDEDTRADITIONALSTYLINGCAPABILITIESTHEYCOULDPROVETHATTHEYCOULDWORKSUCCESSFULLYWITHOUTHEAVYRELIANCEONSKETCHES,SHORTENINGTHEDEVELOPMENTCYCLEBYCROSSINGBOUNDARIESTHEMSELVESTHESEAIMSREFLECTTHEMOVEBYSOMESTYLISTSINTODIRECTMODELLING,WHEREAMOREDEVELOPEDCONCEPTISAVAILABLEFASTER本科生毕业设计（论文）第7页DEBATESINDESIGNEDUCATIONANDINSTYLINGSTUDIOSREFLECTCONFLICTWITHINTHEINDUSTRYABOUTHOWMUCHTIMESTYLISTSSHOULDSPENDINDEVELOPINGSURFACES,ANDWHETHERTHEYSHOULDBEATTEMPTINGTODOSOASREPORTEDINOWEN10,AFEWSTYLISTSPREFERINITIALCLAYMODELLING,THOUGHMOSTPREFERINITIAL2DSKETCHINGBECAUSEBOTHSTUDENTSUSEDTHISCOMPUTERBASEDSTRATEGY,DIRECTCOMPARISONISPOSSIBLEBETWEENCLAYMODELSASSKETCHESANDWORKINGENTIRELYATTHETUBEFORCONCEPTDESIGN213CASETWONOGOINGBACKTHISSTUDENTWASCONFIDENTTHATHISCLAYANDCOMPUTERMODELLINGSKILLSWEREFULLYDEVELOPEDHECHOSETOMAKEONLYAFEW2DSKETCHESTOSHOWOTHERSHISINTENTIONS,ANDNOINTERIORDIALOGUEONESHEASSIGNEDTWODAYSAWEEKTOTHEPROJECT,THOUGHEVENTUALLYHISPROFESSIONALCOMMITMENTSLEFTHIMONLYENOUGHTIMETOPRODUCEONEFINISHED3DCOMPUTERMODELBEFOREFIVEAXISMILLINGHEMADETHEBASICCOMPUTERMODELWITHTHESTYLINGLINESMETHODANDTHENBUILTSURFACESWITHATOOLTHATENFORCEDCONTINUITYOFCURVATUREHECHECKEDTHESURFACESANDTHEINTERSECTIONSWITHTHEMODELLERSVERIFICATIONTOOLSWHENHEHADCHECKEDTHEMODEL,HEHADITMILLEDINPOLYURETHANEFOAMEXCEPTWHERETHECUTTERWASTOOLARGE,AROUNDTHEBASEOFTHEAPOST,THEMODELWASACCEPTABLYMILLEDINONEPASSTHEOCCLUDEDAPOSTINTERSECTIONWASREPAIREDWITHPOLYESTERFILLERANDTHEMODELLIGHTLYSANDEDTOREMOVEEVIDENCEOFTHECUTTERPATHITWASTHENREADYFORPAINTINGANDPRESENTATIONWHENTHEMODELHADONLYPRIMERPAINTONITHEJUDGEDTHESURFACESBYEYEANDFOUNDTHEMCOMPARABLETOANEQUIVALENTCLAYMODELHEWASSLIGHTLYUNHAPPYWITHTHEDIRECTIONANDSHAPEOFHIGHLIGHTSONONESMALLAREAOFTHEREARCPOST,ANDTHISWASCORRECTEDBYHANDSANDINGANDREPAINTINGHETHENMADEANANIMATIONTOSHOWTHEVEHICLEINCONTEXTTHISUSEDBOTHLIVEANDCOMPUTERGENERATEDIMAGESOFHISVEHICLEBEINGDRIVENAROUNDTHEJAGUARCOMPOUNDINCONVOYWITHREALCARSFIG5ANDFIG6FIG5FINISHEDMODELMILLEDDIRECTLYON5AXISMILLINGSETUPVIEWWITHINARTICLE本科生毕业设计（论文）第8页FIG6MILLINGINPROGRESSVIEWWITHINARTICLE214CASETHREEASAFEAPPROACHTHISSTUDENTSWORKINGCIRCUMSTANCESWERESIMILARTOTHOSEINCASETWOHESKETCHEDMORECONVENTIONALLY,MAKINGSKETCHESBOTHTOGENERATEIDEASANDTOSHOWOTHERSHISINTENTIONSFROMTHEBEGINNING,HEINTENDEDTOMILLHISMODELINCLAYSOTHATANYPROBLEMSWITHITCOULDBEAMENDEDWITHCONVENTIONALMODELLINGMETHODS,ANDHEALLOTTEDTIMETODOTHISHEDIDMOSTOFHISMODELLINGWITHTHECOMPUTER,SUPPORTINGITWITHCONCURRENTDETAILSKETCHINGWHENNECESSARYHISDESIGNHADCUTOUTSECTIONSAROUNDTHEROOFLINE,ANDHEFOUNDAGOODSOLUTIONBYMAKINGACOMPLETEPRIMARYSURFACEFROMWHICHTHECUTOUTSWOULDBEREMOVEDAFTERMILLINGTHEMODELWASMILLEDINCLAY,AGAININONEPASS,ANDHEJUDGEDTHESURFACESTOBEUPTOSTANDARDASHEWASMORETHANHAPPYWITHTHEFINISHEDMODELBEFOREDOINGTHECUTOUTS,HECONTINUEDWITHTHECASTINGANDPAINTINGPROCESSANDFINISHEDWITHOUTMAKINGMAJORCHANGESFIG7ANDFIG8FIG7SAFEAPPROACHCOMPUTERMODELVIEWWITHINARTICLEFIG8SAFEAPPROACHFINISHEDMODELVIEWWITHINARTICLE22EVALUATIONOFDIRECTMODELLINGINALLTHREECASESTUDIES,THEMETHODSUSEDPRODUCEFEWERCONCEPTIDEASTHANTHETRADITIONAL本科生毕业设计（论文）第9页STYLINGMETHODTHISDOESNOTPERSEINVALIDATETHEDIRECTMODELLINGAPPROACHTHEREMAYBESCOPETOINCLUDEDIRECTCOMPUTERMODELLINGATTHECONCEPTSTAGEIFTHETRADITIONALQUANTITYOFSKETCHINGISREQUIRED,THEDIRECTMODELLINGMETHODMAYBEUSEDAFTERWEEKTHREEWHENAPPROPRIATECONCEPTSFORDEVELOPMENTARECHOSENTHISISTHEPOINTINTHECONVENTIONALPROCESSWHEREROUGHCLAYORFOAMMODELSMAYHAVEBEENPRODUCEDFORINITIAL3DEVALUATIONINCASESTUDYONE,THESIMULTANEOUSAPPROACHHASCLEARADVANTAGESIFAPPLIEDAFTERTHEINITIALGENERATIONOFCONCEPTSONPAPERROUGHFORMRESOLUTIONINTHESTYLINGSTUDIOOFFERSSOMEVERIFICATIONTHOUGHSTILLALLOWINGDEVELOPMENTOFRELATEDCONCEPTDESIGNSCHOOSINGTOADVANCEWITHEITHERCOMPUTINGORCLAYDEPENDSONTHEAPPEARANCECHOSENFOREXAMPLE,CROSSSECTIONALINFORMATIONFROMTHECLAYCANFORMAFRAMEWORKFORANIMPROVEDCOMPUTERMODELINTHESECONDCASESTUDY,THENOGOINGBACKAPPROACHPRODUCESONLYONECONCEPTDESIGNONLYAFEWDESIGNERSWORKENTIRELYINCLAYORWITHTHECOMPUTER,ANDTHENONLYTOSOLVEPROBLEMSBEYONDTHESCOPEOFSKETCHINGMOSTSTYLISTSFINDWORKINGENTIRELYINCLAYTOODIFFICULTORINCONVENIENTPRESENTINGDESIGNSINTHISWAYMAYENCOURAGEINDIVIDUALSTOFORCETHEIRDESIGNFORWARDWHENINCOMPETITIONFORFURTHERDEVELOPMENTBYPRESENTINGAMOREFINISHEDDESIGNTHESAFEAPPROACHCASETHREEALLOWSRAPIDPRODUCTIONOFSOLIDMODELSAFTERTHEINITIALCONCEPTDRAWINGPHASEMAJORSURFACESCANBEESTABLISHEDQUICKLYINTHECOMPUTERTHISRESULTSINMILLED,BUTINTENTIONALLYUNFINISHEDMODELSTHATARELATERREFINEDBYHANDINCLAYFORWARDPLANNINGANDASTRUCTUREDBUTMUTABLEAPPROACHTOEACHSHAPEARENEEDEDINTHISMETHOD3SKETCHMAPPINGRESEARCHONTHISMETHODSTARTEDATCOVENTRYUNIVERSITYIN1994ITHADTOUSE,TOTHEMAXIMUMPRACTICALEXTENT,CONVENTIONALSTYLINGSKETCHESTHEINTENTIONWASTHATMODELSCOULDBEBUILTDIRECTLYFROMTHEMASQUICKLYANDASEFFICIENTLYASTHESKETCHESTHEMSELVESAREMADETHEMETHODHADTORETAINTHESPONTANEOUSVISUALCREATIVITYANDVITALITYOFTHESKETCHINGPROCESSITWOULDALSOOVERCOMETHELIMITATIONSOFA2DIMENSIONALREPRESENTATIONSEENFROMASINGLEVIEWPOINTBYADDINGTHETHIRDDIMENSIONINANANIMATEDPRESENTATIONTHEINITIALVERSIONOFTHEPROCESSUSEDELEVATIONALDRAWINGSTOMAKETHEBASEMODELINTERSECTINGTHEELEVATIONALOUTLINESGAVEACOARSEGRAPHICREPRESENTATIONOFTHEFORMITWASIMMEDIATELYOBVIOUSTHATTHISHADLITTLERESEMBLANCETOACONCEPTSKETCH,ANDWOULDBEANINADEQUATESUBSTITUTEFORONE31TEXTUREMAPPINGTHENEXTDEVELOPMENTOFTHEPROCESSWASTHEUSEOFTEXTUREMAPPINGTHISATTACHESTHESTYLISTSCONCEPTSKETCHESTOTHEBASEMODELBYRENDERINGTHEMONTOTHEMODELANDTHENFIXINGTHEMTOIT,SOTHATWHENTHEFORMISROTATEDTHESKETCHSTAYSATTACHEDTHECLAYANALOGYWOULDBEPROJECTINGTRANSPARENCIESOFTHESKETCHESONTOACLAYANDPAINTINGTHESURFACETOMATCHTHERESULTISA本科生毕业设计（论文）第10页SIMPLE3DIMENSIONALSKETCHTHATCANBEROTATEDSEETOVEY11FORAMOREDETAILEDTREATMENTTHISISAFAMILIARIDEATODESIGNEDUCATORSDESIGNSTUDENTSOFTENCUTANDPASTETHEIRDRAWINGSANDATTACHTHEMTOMODELSTOEVALUATETHEIR3DCHARACTERISTICSTHETEXTUREMAPPINGPROCESSGIVESBETTERRESULTS,HOWEVERTHETECHNIQUEHASOTHERUSESITCANBEUSEDTOCREATERECOGNISABLEREPRESENTATIONSOFPEOPLEBYTEXTUREMAPPINGAPHOTOGRAPHOFAFACEONTOASTANDARDHEADFORM,ASDESCRIBEDINOWEN,TOVEY,ANDDEKKER4FIG9FIG9ORTHOGRAPHICSKETCHESMAPPEDONTOABASEMODELVIEWWITHINARTICLE32THEDEMONSTRATORTHESEINITIALDEVELOPMENTSOFTHEPROCESSWEREASSEMBLEDINTOADEMONSTRATORTHISCOVEREDTHEPROCESSINTHREEPHASESORTHOGRAPHICPASTINGPERSPECTIVEPASTINGMODELREFINEMENT321ORTHOGRAPHICPASTINGLINEINFORMATIONFROMELEVATIONALSKETCHESISUSEDTOCREATEAWIREMODELONLYPACKAGERELATEDSKETCHESAREGENERALLYUSEFULBECAUSETHEYHADSUFFICIENTDIMENSIONALRIGOURSURFACEPATCHESAREBUILTBETWEENTHELINES,GIVINGACRUDEBUTEFFECTIVE3DMODELTHESKETCHESARETHENTEXTUREMAPPEDONTOTHEMODELTHISRETAINSTHEGRAPHICCHARACTERISTICSANDMANNERISMSOFTHESKETCHES,ANDTHUSTHEESSENTIALTHEMATICELEMENTSOFTHEDESIGNTHERESULTISA3DORTHOGRAPHICSKETCHMAPPEDMODELWHICHCANBEANIMATED,ROTATEDANDSCALEDTHEMAJORPROBLEMWITH