Tradigital Blender: A CG Animator's Guide to Applying the Classic Principles of Animation

304 Pages·2011·38.82 MB·English

by  Roland Hess

Tradigital Blender
Tradigital Blender
’
A CG Animator s Guide to Applying
the Classic Principles of Animation
Roland Hess
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CHAPTER 1
An Introduction to Character
Animation in Blender
Animation asboth an artformand popular entertainment hasexistedfor
almost a century now.Theearly attempts werereceived enthusiastically
more fortheir novelty thanforthequality of theircraft. Thatevenholds
true today: animatedmovies often makeitthrough thestudio process not
because of theirtrue entertainmentvalue, butbased on thenovelty ofthe
technological innovation oftheday. Itturnsout thatthe truecoreof
quality animation asboth artand entertainment lies inthejoining oftwo
elements: acompellingstory andsuperior character animation.
Before wegettoo lofty though,let’stake alittle test.
Are you ananimator at heart?Answer“True”of“False”tothese questions!
1. Ithink Icould have beenan actor ifonlymyface didn’tlook likethis.
2. My techiefriends think I’ma littletoo artsy.
TradigitalBlender.DOI:10.1016/B978-0-240-81757-6.00001-X
©2011ElsevierInc.Allrightsreserved. 1
Tradigital Blender
3. Myartsy friends thinkI’ma littletoo techie.
4. Icanspend longhours pouring intenselyfocused attention into a single
thing.
Ifyouanswered “True”to allofthosequestions, or simplyfound yourself
noddingindepressed silence,then youprobablyhave whatittakes. Ifnot,
youcanfake it,and Ipromise not totell anyone.
Character Animation
To put it as simply as possible, character animation in computer graphics
(CG) consists of posing a digital puppet, recording those poses along a
time line, and then playing them back in real time as the computer
interpolates between the poses. Later in this chapter, we’ll take a look at
the tools you can use to do this. Beyond the simple mechanics though,
where do you begin? How do you know what pose to use, and when to
use it?
The good news is that over the last hundred years, and particularly
beginning with the 1950s, professional animators learned a lot about the
language of character animation: what you can do, what you can’t (or at
least shouldn’t) do, and what looks like life on the screen. A curious
thing happens if you take real footage of a person engaged in some
kind of action and trace over it, creating a kind of animation called
rotoscoping. You would think that something traced from real life and
motion would make the best animation, because all of its actions and
reactions are perfectly true to life. The balance. The physics. The
velocities.
Tothecontrary, rotoscoping gives youa fairlydeadresult. Itlooks okay, but
there’s clearly something missing, eventhough everyline and jotistaken
exactlyfromreal life. Thepoint is that, likewith so manyother art forms,
thegoalof an animatorisnot toexactly duplicatethereal world, but to
implementtools andtechniques that givetheillusion ofrealitywhen
observed. Infact, onceyoulearnthe techniquesand rulesof animation,
youcanpushthe boundaries ofrealityquite abit and getyour viewer to
accept asbelievablethingsthat simply aren’t possible.
Fortunately for allof us,thepreceding generations ofanimators have
alreadycracked thisparticular code.Through research,hard work, and alot
oftrial and error, theydetermineda setof rulesand tricksthat when
followedcan helpto giveyour ownanimationsthefeeling oflife. Notall
animators(or books, for that matter) agreeonexactly whatthese rulesare,
orexactlyhowmuchemphasis you should puton oneover theother.
However, thereisan acknowledged“core”set ofrules that aregenerally
used whenteaching, and these arereferred to asthe “Twelve Principles of
Animation.”
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An Introduction to Character Animation in Blender
The Twelve Principles
Throughout therest ofthebook, we’ll beanimating asingle shotusing
these principles. As wedothat, you’llseeexactly whereand howtheyfit
into the animationwork flow. Fornowthough,let’sgetan overviewof the
principles themselves.Inorder todemonstrate them, weneedamodel. The
animation puppet that’sincluded with this book will do.Sayhito “Junot”
(Fig.1.1). Thecharacter hasfour different skins, two femaleand two male,
one each witha full skin (like inthefigure) andanother made ofseparate
parts. Youcan see“Meyer” (theguy)in “tincan”modein theother halfof
Fig. 1.1.Looking good,Meyer. Looking reallygood.
Squash and Stretch
In real life,when youjump fromyour porch and landontheground, your
knees and spine bendtoabsorb theimpact. Theyonlybendat thejoints
though, obviously. Thebonesthemselves don’t compress orflex inany
noticeable fashion. Ifthey did,itwouldbe…bad. Likewise,if youwereto
slice your handquickly through theair (kiya!),your handwouldstaythe
same shape, no matterhowfastyou didit. Intheworld ofanimation, this
is not thecase.Depending onhowstylized your animation will be,and
howdrastic themotions involved, actuallysquashingand stretching the
otherwise rigid structures of thebodycan addlife tothefinal result.
In Fig.1.2,youcan seeJunot flying(or falling). Boththeextended armand
the bodyitself have beenstretcheda bit.The effect isn’t drastic, and inthis
case, youmightnot have evennoticed due totheforeshortening
FIG1.1(a–c) Junot Strikes a Pose. Meyer Does the Same.
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Tradigital Blender
FIG1.2 Junot Stretching as She
Flies.
introduced by thecamera angle. But it’s inthere,and ifused for abrief
momentinthemiddle of afastaction, itwould addlifeto theanimation,
helpingtoemphasize herhighforward velocity.
Let’smeet one morecharacter: Smith. Smithis thesame basic puppetas
Meyerand Junot,but hehasbeengiven cartoon-like proportions. A
character likeSmith canendure a lotmore squashand stretch during
animationthanhis more realistically proportioned siblings. Fig. 1.3 shows
Smithlanding froma leap,withand without squashand stretch.
Therulesare this: thefaster theaction, themoresquash andstretch you
need.Themore realisticthe character,theless youshould use.So, a
character likeSmith whoisbouncing around theroom like DaffyDuck will
mostlikely exhibit some extremesquash andstretch. IfJunot and Meyer
weresittingon apark benchplaying agame ofchess, theywouldhave
almostnone.
Anticipation
InFig.1.4,Meyerisabouttothrowadevastatingpunch.What’sthatyousay?
Heisn’t?Clearly,Meyerdoesnotlooklikesomeonewhoisabouttostrike.
MythsaboutBruceLeebeingabletodeliveradevastatingblowfrommere
inchesawaywithoutanykindofwindupaside,whenoneperson—andthus,
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An Introduction to Character Animation in Blender
FIG1.3(a,b) Smith Just Fell Off
the Roof. Don’t Worry. He’s Okay.
FIG1.4 Are You Gonna Do
Something, or Just Stand There and
Bleed?
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Tradigital Blender
a character—does something, one almost always anticipates the action.
The larger or more forceful the final action, the correspondingly big the
anticipation must be to make it feel right.
Anticipationhelpstobringbalancetoyouranimation,notinthesenseofleft-
to-rightorinmakingsurethatthecharacter’sweightmakessenseoverits
pointsofsupport,butbalanceintime.Whatcomesafternecessitatesthat
somethingcomesbefore.Wedon’tthinkaboutitinthosetermswhenwego
aboutourdailylives,butthatisonlybecauseourbodiesaresogoodabout
planningaheadforus.Almostconstantly,ourbodiesareonestepaheadofus,
preparingthemselvesforthenextthingthattheyalreadyknowwearegoing
todo.Whathappenswhenourbodiesdon’tplanproperlyandthat
anticipationdoesn’thappen?Weturnaroundandwalkintothedoor(orflying
ball,orcar)wedidn’tseeandawholedifferentbranchofphysicstakesover.
Additionally, anticipation can beused to graband direct theviewer’s
attention.Notonlydoes itprovide theproperphysics, butitalso shouts
“LookwhatI’mabout to do!”(Fig.1.5).
FIG1.5 Meyer Now Actually Ready
to Heave-ho.
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