三維建模外文資料翻譯人體動(dòng)畫基礎(chǔ)

FundamentalsofHumanAnimation(FromPeterRatner.3DHumanModelingandAnimation[M].America:Wiley,2003:243~249)Ifyouarereadingthispart,thenyouhavemostlikelyfinishedbuildingyourhumancharacter,createdtexturesforit,setupitsskeleton,mademorphtargetsforfacialexpressions,andarrangedlightsaroundthemodel.Youhavethenarrivedatperhapsthemostexcitingpartof3-Ddesign,whichisanimatingacharacter.Uptonowtheworkhasbeensomewhatcreative,sometimestedious,andoftendifficult.Itisverygratifyingwhenallyourpreviouseffortsstarttopayoffasyouenlivenyourcharacter.Whenanimating,thereisacreativeflowthatincreasesgraduallyovertime.Youarenowatthephasewhereyoubecomeboththeactorandthedirectorofamovieorplay.Althoughanimationappearstobeamorespontaneousact,itisneverthelessjustaschallenging,ifnotmoreso,thanallthepreviousstepsthatleduptoit.Youranimationswilllookpitifulifyoudonotunderstandsomebasicfundamentalsandprinciples.Thefollowingpointersaremeanttogiveyousomedirection.Feelfreetoexperimentwiththem.Bendandbreaktheruleswheneveryouthinkitwillimprovetheanimation.SOMEANIMATIONPOINTERS1.Tryisolatingparts.Sometimesthisisreferredtoasanimatinginstages.Ratherthantryingtomoveeverypartofabodyatthesametime,concentrateonspecificareas.Onlyonesectionofthebodyismovedforthedurationoftheanimation.Thenreturningtothebeginningofthetimeline,anothersectionisanimated.Bysuccessivelyreturningtothebeginningandanimatingadifferentparteachtime,theentireprocessislessconfusing.2.Putinsomelagtime.Differentpartsofthebodyshouldnotstartandstopatthesametime.Whenanarmswings,thelowerarmshouldfollowafewframesafterthat.Thehandswingsafterthelowerarm.Itislikeachainreactionthatworksitswaythroughtheentirelengthofthelimb.3.Nothingevercomestoatotalstop.Inlife,onlymachinesappeartocometoadeadstop.Muscles,tendons,force,andgravityallaffectthemovementofahuman.Youcanprovethistoyourself.Trypunchingtheairwithafullextension.Noticethatyourfisthasabounceattheend.Ifapartcomestoastopsuchasamotionhold,keyframeitonceandthenagainafterthreetoeightormorekeyframes.Yourmotiongraphwillthenhaveacurvebetweenthetwoidenticalkeyframes.Thiswillmakethepartappeartobounceratherthancometoadeadstop.4.Addfacialexpressionsandfingermovements.Yourdigitalhumanshouldexhibitsignsoflifebyblinkingandbreathing.Ablinkwillnormallyoccurevery60seconds.Atypicalblinkmightbeasfollows:Frame60:Botheyesareopen.Frame61:Therighteyecloseshalfway.Frame62:Therighteyeclosesallthewayandthelefteyecloseshalfway.Frame63:Therighteyeopenshalfwayandthelefteyeclosesalltheway.Frame64:Therighteyeopensallthewayandlefteyeopenshalfway.Frame65:Thelefteyeopensalltheway.Closingtheeyesatslightlydifferenttimesmakestheblinklessmechanical.Changingfacialexpressionscouldbejustusingeyemovementstoindicatethoughtsrunningthroughyourmodel'shead.Thehandswillappearstiffifyoudonotaddfingermovements.Toomanystudentsaretoolazytotakethetimetoaddfacialandhandmovements.Ifyoumaketheextraeffortforthesedetailsyouwillfindthatyouranimationsbecomemuchmoreinteresting.5.Whatisnotseenbythecameraisunimportant.Ifanarmgoesthroughalegbutisnotseeninthecameraview,thendonotbothertofixit.Ifyouwantahandtoappearclosetothebodyandthecameraviewmakesitseemtobecloseeventhoughitisnot,thenwhymoveitanycloser?Thisalsoappliestosets.Thereisnoneedtobuildanentirehouseifalltheactiontakesplaceinthelivingroom.Considerpaintingbackdropsratherthanmodelingeverypartofascene.6.Useaminimumamountofkeyframes.Toomanykeyframescanmakethecharacterappeartomoveinspasticmotions.Sharp,cartoonlikemovementsarecreatedwithcloselyspacedkeyframes.Floatyorsoft,languidmotionsaretheresultofwidelyspacedkeyframes.Ananimationwilloftenbeamixtureofboth.Trytolookforwaysthatwillabbreviatethemotions.Youcanretaintheessentialelementsofananimationwhilereducingtheamountofkeyframesnecessarytocreateagesture.7.Anchorapartofthebody.Unlessyourcharacterisintheair,itshouldhavesomepartofitselflockedtotheground.Thiscouldbeafoot,ahand,orboth.Whicheverportionisonthegroundshouldbeheldinthesamespotforanumberofframes.Thispreventsunwantedslidingmotions.Whenthemodelshiftsitsweight,thefootthattouchesdownbecomeslockedinplace.Thisisespeciallytruewithwalkingmotions.Thereareanumberofwaystolockpartsofamodeltotheground.Onemethodistouseinversekinematics.Thegoalobject,whichcouldbeanull,automaticallylocksafootorhandtothebottomsurface.Anothermethodistomanuallykeyframethepartthatneedstobemotionlessinthesamespot.Thecharacteroritslimbswillhavetobemovedandrotated,sothatfootorhandstaysinthesameplace.Ifyouareusingforwardkinematics,thenthiscouldmeankeyframingpracticallyeveryframeuntilitistimetounlockthatfootorhand.8.Acharactershouldexhibitweight.Oneofthemostchallengingtasksin3-Danimationistohaveadigitalactorappeartohaveweightandmass.Youcanuseseveraltechniquestoachievethis.Squashandstretch,orweightandrecoil,oneofthe12principlesofanimationdiscussedinChapter12,isanexcellentwaytogiveyourcharacterweight.Byaddingalittlebouncetoyourhuman,heorshewillappeartorespondtotheforceofgravity.Forexample,ifyourcharacterjumpsupandlands,liftthebodyupalittleafteritmakescontact.Foraheavycharacter,youcandothisseveraltimesandhaveitdecreaseovertime.Thiswillmakeitseemasiftheforceofthecontactcausesthebodytovibratealittle.Secondaryactions,anotheroneofthe12principlesofanimationdiscussedinChapter12,areanimportantwaytoshowtheeffectsofgravityandmass.Usingthepreviousexampleofajumpingcharacter,whenheorshelands,thebellycouldbounceupanddown,thearmscouldhavesomespringtothem,theheadcouldtiltforward,andsoon.Movingorvibratingtheobjectthatcomesincontactwiththetravelingentityisanothermethodforshowingtheforceofmassandgravity.Afloorcouldvibrateorachairthatapersonsitsinrespondtotheweightbytheseatgoingdownandrecoveringbackupalittle.Sometimesananimatorwillshakethecameratoindicatetheeffectsofaforce.Itisimportanttotakeintoconsiderationthesizeandweightofacharacter.Heavyobjectssuchasanelephantwillspendmoretimeontheground,whilealightcharacterlikearabbitwillspendmoretimeintheair.Thehoppingrabbithardlyshowstheeffectsofgravityandmass.9.Takethetimetoactouttheaction.Sooften,itistooeasytojustsitatthecomputerandtrytosolvealltheproblemsofanimatingahuman.Putsomelifeintotheperformancebygettingupandactingoutthemotions.Thiswillmakethecharacter'sactionsmoreuniqueandalsosolvemanytimingandpositioningproblems.Thebestanimatorsarealsoexcellentactors.Amirrorisanindispensabletoolfortheanimator.Videotapingyourselfcanalsobeagreathelp.10.DecidewhethertouseIK,FK,orablendofboth.Forwardkinematicsandinversekinematicshavetheiradvantagesanddisadvantages.FKallowsfullcontroloverthemotionsofdifferentbodyparts.Abonecanberotatedandmovedtotheexactdegreeandlocationonedesires.ThedisadvantagetousingFKisthatwhenyourpersonhastointeractwithinanenvironment,simplemovementsbecomedifficult.Anchoringafoottothegroundsoitdoesnotmoveischallengingbecausewheneveryoumovethebody,thefeetslide.Ahandrestingonadeskhasthesameproblem.IKmovestheskeletonwithgoalobjectssuchasanull.UsingIK,thetaskofanchoringfeetandhandsbecomesverysimple.ThedisadvantagetoIKisthatagreatamountofcontrolispackedtogetherintothegoalobjects.Certainposesbecomeverydifficulttoachieve.Iftheupperbodydoesnotrequireanyinteractionwithitsenvironment,thenconsiderablendofbothIKandFK.IKcanbesetupforthelowerhalfofthebodytoanchorthefeettotheground,whileFKontheupperbodyallowsgreaterfreedomandprecisionofmovements.Everysituationinvolvesadifferentapproach.Useyourjudgmenttodecidewhichsetupfitstheanimationmostreliably.11.Adddialogue.Ithasbeensaidthatmorethan90%ofstudentanimationsthataresubmittedtocompanieslackdialogue.Thefewthatincorporatespeechintheiranimationsmaketheirworkhighlynoticeable.Iftheanimationanddialoguearewelldone,thenthosefewhaveagreateradvantagethantheircompetition.Companiesunderstandthatittakesextraeffortandskilltocreateanimationwithdialogue.Whenyouplanyourstory,thinkaboutcreatinginteractionbetweencharactersnotonlyonaphysicallevelbutthroughdialogueaswell.Thereareseveraltechniques,discussedinthischapter,thatcanbeusedtomakedialoguemanageable.12.Usethegrapheditortocleanupyouranimations.Thegrapheditorisausefultoolthatall3-Danimatorsshouldbecomefamiliarwith.Itisbasicallyarepresentationofalltheobjects,lights,andcamerasinyourscene.Itkeepstrackofalltheiractivitiesandproperties.Agooduseofthegrapheditoristocleanupmorphtargetsafteranimatingfacialexpressions.Ifthedefaultincomingcurveinyourgrapheditorissettoarcsratherthanstraightlines,youwillmostlikelyfindthatsometimessplinesinthegrapheditorwillcurvebelowavalueofzero.Thiscanyieldsomeunpredictableresults.Thefacialmorphtargetsbegintotakeonnegativevaluesthatleadtoundesirablefacialexpressions.Wheneveryouseeacurvebendbelowavalueofzero,selectthefirstkeyframepointtotherightofthearcandsetitscurvetolinear.Amoredetaileddiscussionofthegrapheditorwillbefoundinalaterpartofthischapter.ANIMATINGINSTAGESAllthevariouscomponentsthatcanbemovedonahumanmodeloftenbecomeconfusingifyoutrytochangethematthesametime.Theperformancequicklydeterioratesintoamechanicalroutineifyoutrytoalterallthesepartsatthesamekeyframes.Remember,youaretryingtocreatehumanqualities,notroboticones.Isolatingareastobemovedmeansthatyoucanlookforthepartsofthebodythathavemotionovertimeandconcentrateonjustafewofthose.Forexample,thefirstthingyoucanmoveisthebodyandlegs.Whenyouaredonemovingthemaroundovertheentiretimeline,thentryrotatingthespine.Youmightdothisbymovingindividualspinebonesorusinganinversekinematicschain.Nowthatyouhavethebodymovingaroundandbending,concentrateonthearms.IfyouarenotusinganIKchaintomovethearms,hands,andfingers,thenrotatethebonesfortheupperandlowerarm.Donotforgetthewrist.Fingermovementscanbeanimatedasoneofthelastparts.Facialexpressionscanalsobeanimatedlast.ExamplemoviesshowingthesamecharacteranimatedinstagescanbeviewedontheCD-ROMasCD11-1AnimationStagesMovies.SomesampleimagesfromtheanimationscanalsobeseeninFigure11-1.Thefirstmovieshowsmovementonlyinthebodyandlegs.Duringthesecondstage,thespineandheadwereanimated.Thethirdtime,thearmsweremoved.Finally,inthefourthandfinalstage,facialexpressionsandfingermovementswereadded.Animatinginsuccessivepassesshouldsimplifytheprocess.Somefinalstageswouldbeusedtocleanuporedittheanimation.Sometimestheanimationswitchesfromonepartofthebodyleadingtoanother.Forexample,somewhereduringthemiddleofananimationtheupperbodybeginstoleadthelowerone.Inacaselikethis,youwouldthenswitchfromanimatingthelowerbodyfirsttomovingtheupperpartbeforethelowerone.Theorderinwhichoneanimatescanbeamatterofpersonalchoice.Somepeoplemayprefertodofacialanimationfirstorperhapstheyliketomovethearmsbeforeanythingelse.Followingisasummaryofhowsomeonemightanimateahuman.1.Firstpass:Movethebodyandlegs.2.Secondpass:Moveorrotatethespinalbones,neck,andhead.3.Thirdpass:Moveorrotatethearmsandhands.4.Fourthpass:Animatethefingers.5.Fifthpass:Animatetheeyesblinking.6.Sixthpass:Animateeyemovements.7.Seventhpass:Animatethemouth,eyebrows,nose,jaw,andcheeks(youcanbreaktheseupintoseparatepasses).Mostmovementstartsatthehips.Athletesoftenbeginwithawindupactioninthepelvicareathatworksitswayoutwardtotheextremepartsofthebody.Thiswhiplikeactivitycanevenbeobservedinjustaboutanymundaneact.Itisinterestingtonotethatpeoplewhostudymartialartslearnthatmostoftheirpowercomesfromthelowertorso.Studentsareoftentoolazytomakefingermovementsapartoftheiranimation.Thereareseveralmethodsthatcanmaketheprocesslesstimeconsuming.Onewayistocreatemorphtargetsofthefingerpositionsandthenuseshapeshiftingtomovethevariousdigits.Eachfingerispositionedinanopenandfistlikeclosedposture.Forexample,thesectionsoftheindexfingerareclosed,whiletheothersareleftinanopen,relaxedpositionforonemorphtarget.Thenextmorphtargetwouldhaveonlytheringfingerclosedwhilekeepingtheothersopen.Duringtheanimation,slidersarethenusedtoopenandclosethefingersand/orthumbs.Anothermethodtocreatefingermovementsistoanimatetheminbothclosedandopenpositionsandthensavethemotionfilesforeachdigit.Anytimeyouanimatethesamecharacter,youcanloadthemotionsintoyournewscenefile.Itthenbecomesasimpleprocessofselectingeithertheclosedortheopenpositionforeachfingerandthumbandkeyframingthemwhereveryoudesire.DIALOGUEKnowinghowtomakeyourhumanstalkisacrucialpartofcharacteranimation.Onceyouadddialogue,youshouldnoticealivelierperformanceandagreaterpersonalityinyourcharacter.Atfirst,dialoguemayseemtoogreatachallengetoattempt.Actually,ifyoufollowsomesimplerules,youwillfindthataddingspeechtoyouranimationsisnotasdauntingataskasonewouldthink.Thefollowingsuggestionsshouldhelp.DIALOGUEESSENTIALS1.Lookinthemirror.Beforeanimating,useamirrororareflectivesurfacesuchasthatonaCDtofollowlipmovementsandfacialexpressions.2.Theeyes,mouth,andbrowschangethemost.Thepartsofthefacethatcontainthegreatestamountofmusclegroupsaretheeyes,brows,andmouth.Therefore,thesearetheareasthatchangethemostwhencreatingexpressions.3.Theheadconstantlymovesduringdialogue.Animaterandomheadmovements,nomatterhowsmall,duringtheentireanimation.Involuntarymotionsoftheheadmakeapointwithouthavingtostateitoutright.Forexample,noddingandshakingtheheadcommunicate,respectively,positiveandnegativeresponses.Leaningtheheadforwardcanshowanger,whileadownwardmovementcommunicatessadness.Movetheheadtoaccentuateandemphasizecertainstatements.Listentothewordsthatarestressedandaddextraheadmovementstothem.4.Communicateemotions.Therearesixrecognizableuniversalemotions:sadness,anger,joy,fear,disgust,andsurprise.Other,moreambiguousstatesarepain,sleepiness,passion,physicalexertion,shyness,embarrassment,worry,disdain,sternness,skepticism,laughter,yelling,vanity,impatience,andawe.5.Usephonemesandvisemes.Phonemesaretheindividualsoundswehearinspeech.Ratherthantryingtospelloutaword,recreatethewordasaphoneme.Forexample,thewordcomputerisphoneticallyspelled"cumpewtrr."Visemesarethemouthshapesandtonguepositionsemployedduringspeech.Ithelpstremendouslytodrawachartthatrecreatesspeechasphonemescombinedwithmouthshapes(visemes)aboveorbelowatimelinewiththeframesmarkedandthesoundandvolumeindicated.6.Neveranimatebehindthedialogue.Itisbettertomakethemouthshapesoneortwoframesbeforethedialogue.7.Don'toverstate.Realisticfacialmovementsarefairlylimited.Themouthdoesnotopenthatmuchwhentalking.8.Blinkingisalwaysapartoffacialanimation.Itoccursabouteverytwoseconds.Differentemotionalstatesaffecttherateofblinking.Nervousnessincreasestherateofblinking,whileangerdecreasesit.9.Movetheeyes.Tomakethecharacterappeartobealive,besuretoaddeyemotions.About80%ofthetimeisspentwatchingtheeyesandmouth,whileabout20%isfocusedonthehandsandbody.10.Breathingshouldbeapartoffacialanimation.Openingthemouthandmovingtheheadbackslightlywillshowanintakeofair,whileflaringthenostrilsandhavingtheheadnodforwardalittlecanshowexhalation.Breathingmovementsshouldbeverysubtleandhardlynoticeable...外文資料翻譯—譯文部分人體動(dòng)畫基礎(chǔ)(引自PeterRatner.3DHumanModelingandAnimation[M].America:Wiley,2003:243~249)如果你讀到了這部分，說明你很可能已構(gòu)建好了人物角色，為它創(chuàng)建了紋理，建立起了人體骨骼，為面部表情制作了morph修改器并在模型周圍安排好了燈光。接下來就是三維設(shè)計(jì)中最精彩的部分，即制作角色動(dòng)畫。到目前為止有些工作極富創(chuàng)意，有些枯燥乏味，但都困難重重。在經(jīng)過了前期的努力后，角色已顯示出了活力，這是非常令人高興的。在制作動(dòng)畫時(shí)，創(chuàng)意會(huì)隨著時(shí)間的推移不斷涌現(xiàn)?，F(xiàn)在你既是電影和戲劇的演員又是導(dǎo)演。雖然動(dòng)作是很自然的表演，但它即使不比之前的準(zhǔn)備步驟更復(fù)雜，也極具挑戰(zhàn)。如果你不懂一些基礎(chǔ)知識(shí)和基本原理，制作出的動(dòng)畫會(huì)很可笑。以下幾點(diǎn)為你提供一些指導(dǎo)。盡管拿它們做實(shí)驗(yàn)。只要你認(rèn)為能改進(jìn)動(dòng)畫，可隨意遵守或打破這些規(guī)則。動(dòng)畫指南：嘗試分離各部分。有時(shí)指的是分階段制作動(dòng)畫。不要試圖同時(shí)移動(dòng)身體的每個(gè)部位，應(yīng)集中精力制作具體部位的動(dòng)畫。在動(dòng)畫的持續(xù)時(shí)間內(nèi)只移動(dòng)身體的一部分。然后返回時(shí)間軸的起始位置，制作另一部分的動(dòng)畫。通過不斷回到起始位置，每次制作一個(gè)不同部位的動(dòng)畫，能使整個(gè)過程變得清晰明了。添加一些延遲。身體的不同部位不應(yīng)該同時(shí)開始和停止動(dòng)作。當(dāng)胳膊擺動(dòng)時(shí)，下臂應(yīng)該在其隨后擺動(dòng)幾幀。在下臂停止擺動(dòng)后手再擺動(dòng)。整個(gè)手臂的活動(dòng)就像是一邊連串的連鎖反應(yīng)。任何一個(gè)動(dòng)作都不會(huì)戛然而止。生活中，只有機(jī)器會(huì)突然停止。肌肉，腱，壓力和引力都會(huì)影響人體的移動(dòng)。你可以親自證明這一點(diǎn)。用力向前推拳直到完全舒展開手臂。注意最終你的拳頭會(huì)回彈一下。如果一個(gè)部位要停止，例如要保持動(dòng)作，首先把它設(shè)置為關(guān)鍵幀，然后在3到8個(gè)或更多關(guān)鍵幀后再設(shè)置一次關(guān)鍵幀。動(dòng)作圖形會(huì)在兩個(gè)相同的關(guān)鍵幀中間產(chǎn)生一條曲線。這會(huì)使動(dòng)作有一個(gè)回彈而不是馬上停止。添加面部表情和手指動(dòng)作。數(shù)字人體應(yīng)當(dāng)通過眨眼和呼吸來呈現(xiàn)生命的氣息。通常每隔60秒會(huì)眨一下眼睛。典型的眨眼應(yīng)該如下所述：第60幀：兩眼都睜開。第61幀：右眼半合。第62幀：右眼緊閉，左眼半合。第63幀：右眼半睜，左眼緊閉。第64幀：右眼完全睜開，左眼半睜。第65幀：左眼完全睜開。在不同時(shí)間閉上眼睛會(huì)讓眨眼顯得更為自然。面部表情的改變可通過眼睛的轉(zhuǎn)動(dòng)來表明模型腦海中的想法。如果你不添加手指動(dòng)作，手會(huì)顯得過于僵硬。很多同學(xué)懶得花時(shí)間去添加面部和手部動(dòng)作。如果你花額外的努力在這些細(xì)節(jié)上，你的動(dòng)畫會(huì)變得更有趣。攝像機(jī)沒有拍到的內(nèi)容不用關(guān)注。如果胳膊叉到了腿里但攝像機(jī)視圖中看不到，就不用費(fèi)心去更正。如果你希望一只手看上去靠近身體并且攝像機(jī)視角看上去也是如此，即使實(shí)際并不靠近，也沒必要再做調(diào)整。這也適用于布景。如果所有的表演都發(fā)生在起居室，就沒必要建造整幢房子。考慮繪制背景而不是做出場(chǎng)景每一部分的模型。盡量少使用關(guān)鍵幀。過多的關(guān)鍵幀會(huì)讓角色動(dòng)作看上去有痙攣的感覺。劇烈，類似于卡通的動(dòng)作是使用分布密集的關(guān)鍵幀制作的。飄逸或柔和、沒精打采的動(dòng)作是通過分布稀疏的關(guān)鍵幀制作的。動(dòng)畫中通常結(jié)合使用二者。試著尋找可以簡(jiǎn)化動(dòng)作的方法。你可以在保留動(dòng)畫基本元素的同時(shí)減少構(gòu)成姿勢(shì)所需的關(guān)鍵幀數(shù)量。通過鎖定位置錨定身體的某個(gè)部位。除非你的角色在空中，否則它身體的一些部位應(yīng)該被鎖定在地面上?？梢允且恢荒_，一只手或二者。處于地面的部分應(yīng)該在好幾幀上保持在同一位置。這樣可阻止不必要的滑動(dòng)。當(dāng)模型移動(dòng)重量時(shí)，落下的腳被鎖定在適當(dāng)?shù)奈恢?。?duì)于行走動(dòng)作這點(diǎn)特別適用。有很多方法將模型的部位鎖定在地面上。除了直接把一只腳或一只手鎖定在地面外，另一種方法是把需要保持在相同位置的部位手動(dòng)變成關(guān)鍵幀。角色或其四肢必須移動(dòng)或旋轉(zhuǎn)，只有這樣，腳可手才能保持在相同位置。角色應(yīng)該顯示重量。三維動(dòng)畫中最富挑戰(zhàn)性的一項(xiàng)任務(wù)是讓一個(gè)數(shù)字演員顯得擁有重量和質(zhì)量?？梢允褂脦追N方法來實(shí)現(xiàn)。第12章中討論的動(dòng)畫的12個(gè)原理之一的擠壓與拉伸（或者重量與反彈）是為角色提供重量的好方法。通過為人體添加一些反彈動(dòng)作，可以展示角色受到重力影響的效果。比如，如果角色跳起后落下，腳觸地后身體要稍微向上抬一下。對(duì)于一個(gè)比較重的角色，可以讓這個(gè)動(dòng)作重復(fù)幾次，一次比一次弱。這顯示出接觸的力量似乎讓身體微微有些振動(dòng)。第12章中討論的動(dòng)畫的12個(gè)原理中的另外一個(gè)——輔助動(dòng)作是顯示重量和質(zhì)量效果的一種重要方法。就用前面跳躍的角色例子，角色著地時(shí)，腹部可以上下顫動(dòng)，胳膊可以微微彈起，頭可以向前傾斜等。移動(dòng)與正在移動(dòng)的實(shí)體接觸的物體或讓其振動(dòng)是另一種顯示質(zhì)量和重力的方法。地板可以振動(dòng)，有人坐進(jìn)去的椅子通過下陷再稍微彈回也可以顯示出對(duì)重量的反應(yīng)。有時(shí)動(dòng)畫師可以晃動(dòng)攝像機(jī)來表明力量的效果?？紤]角色的大小和重量很重要。較重的物體如大象大部分時(shí)間都在地面上，而較輕的角色如兔子大部分時(shí)間在空中。忙碌的兔子很難顯示出重力和質(zhì)量的效果?；〞r(shí)間表演動(dòng)作。我們很容易只是坐在電腦前，努力解決人體動(dòng)畫的所有問題。站起來，實(shí)際表演一下動(dòng)作，會(huì)給動(dòng)畫注入活力。這會(huì)讓角色的動(dòng)作顯得更為獨(dú)特，也可以解決許多時(shí)間和位置安排問題。最好的動(dòng)畫師也是最優(yōu)秀的演員。對(duì)于動(dòng)畫師來說，鏡子是不可或缺的工具。錄制自己的表演也有很大的用處。決定是否使用IK，F(xiàn)K，或兩者都用。正向運(yùn)動(dòng)和逆向運(yùn)動(dòng)各有其優(yōu)缺點(diǎn)。FK能控制不同身體部位的運(yùn)動(dòng)。一個(gè)骨骼可被旋轉(zhuǎn)移動(dòng)到想要的精確位置和程度。使用FK的缺點(diǎn)是當(dāng)你的角色處在一個(gè)互動(dòng)的環(huán)境內(nèi)，簡(jiǎn)單的移動(dòng)也會(huì)變得困難。當(dāng)你把腳固定在地面上讓它不