MakingObjectsMoveinUnison:
UsingLists
ByDeborahNelson
DukeUniversity
ProfessorSusanRodgerJuly13,2008
UpdatedJune2014byYossra Hamid
EditedforAlice3usebyAnhTrinhJuly2016
Overview
•Thistutorialwillteachyouhowtouselists.Alist
isasortofholdingplaceforarowofobjects.
•Withalist,youcanmakeseveralobjectsdothe
samethingatthesametimewithouthavingto
writeoutcodeforeachone.Youcanalsohave
themdothesamethingoneobjectatatime.
•Wewillusealisttomakeagroupofstuffedtigers
toperformsomeactionsatthesametime,and
thenoneatatime.
LoadingtheWorld
• Openanewworld,withanytemplate.
• Saveitinadirectorythatyoucanfindagain.
• Afteryouhaveopenedthefilegointothe
layoutmodebyclickingontheSetupScene
button(bottomrightcornerofanimation
screen).
• ClickontheCameraMarkersmenu.ClickAdd
CameraMarker.Namethecameraview
originalPosition
AddingtheObjects
• GototheBipedclasses
thenaddfour
StuffedTiger objectsto
yourworld.
• Addtwootherpeople
toyourworld.
• I veaddedthe
SnowMan and
SnowWomanfromthe
Gallery.
Part1:MakingaList
• Wewillusealist tomakeallfourofthetigersjump
upanddowntogetherandthenkickandspinoneat
atime.
• ClickonScenetabinthetopoftheeditor,andthen
clickonAddSceneProperty… undertheunmanaged
section.
• Onceaboxappears,setthevaluetypetoGallery
Class,thenclickonBipedintheSelection columnin
themiddle.Youwillsee6checkmarksintheobject
columnontheleft.Thatmeansthelistcancontains
anybipedcharacterswehaveadded.ClickOK.
Makingalist(cont1)
• Checktheisarraybox
• Namethelistastigers.
• Clickontheinitializer ->CustomArray… ->add
thefourtigersin
ØSeethescreenshotonthenextslideforan
illustration.
Part2:Writingthemethod
• Dragaeachin_togetherintomyFirstMethod.
• Foritemtype:ChooseGalleryClassandcheck
onBipedinthemiddlecolumnlikepreviously
thenclickOK.
• Nametheitematiger
• Forarray:choosethis.characters,itwillshow
asthis.tigers
Writingthemethod(cont1)
Ø Eachin_togethermeansthatalloftheitemsinthe
listwillperformtheinstructionsthatwewilladdat
thesametime.
Eachin_together(cont 1)
• Choose atiger inthedropdownmenuontheleft,drag
turntofacetotheeachintogetherblock, andthen
selectthis.camera.
• Clickonadddetail…tochangethedurationto0.25
seconds.
• Enterinthecodebelowbyselectingthemove
command,firstup1meter,thendown1meter.Make
eachcommand sduration.25seconds.
• Playyourworld.Yourmethodshouldlooklikethis:
Step2: inorder
• Nowdragaforeachin_underneaththeeach
in_together block, chooseBiped asitemtype,
onetiger astheitemname,andthis.tigers asthe
array
Forallinorder(cont1)
ØForeachin_meansthetigerswillperformall
oftheinstructionsthatweaddinsideofit,
onerightaftertheother(intheorderthat
theywereaddedtothelist).
• Wewantthetigerstoeachturntheirleftleg
andspinoneatatime.
• However,theonetiger isjustaplaceholder,so
wecannottellonetiger toturnitsleftleg.
• Wewillhavetouseaclass-levelbuiltin
functiontoturnonlyapartoftheobject.
Foreachin_(cont 2)
• Selectonetiger intheobjecttree.
• Hoveryourmouseattherightarrowsignnext
toonetiger intheobjecttree,thenclickon
onetiger getLeftHip
• Draginturn,thenbackward,then¼
revolution.Setthedurationto.25seconds.
Ø Seethescreenshotonthenextslideforan
illustration.
• Selectonetiger fromtheobjecttreeagain.
• Drag intotheForeachin_ againbelowthe
leftHip command,andselectturn,then right,
then 1revolution.Setthedurationto.25
seconds.
Foreachin_(cont 2)
• Thenchooseonetiger andselectonetiger
getLeftHip likewedidpreviouslyanddrag
anotherturn,then forward,then ¼
revolution.Setthedurationto.25seconds.
• YourForeachin_codeshouldlooklikethisso
far:
Thecompletemethod
• Hereisthecompletemethod.Don tforgetto
commentyourcode!
Playyourworldnow
Step4:Objectswithdifferentparts
• Sofar,ourlistonlyhastigersinit.Addthetwo
otherpeopleobjectstothelist:
1) ClickonScenetabonthetopoftheeditor
2) Underunmanagedsection, clickonthebox
nexttothetigerslist
3) ClickonCustomArray… andselecttheobject
youwanttoadd.
Ø Seethescreenshotonthenextslideforan
illustration.
Warning
• Youcan’taddanon-bipedobjecttoalistof
Bipedobjects
• Addingthesnowman andsnowwoman tothe
listworksbecausetheyareBipedandboth
haveleftHip asthelabelforoneoftheirbody
parts.
• Ifyourcharacterdoesnothaveapartnamed
leftHip youmightgetanerrorbecausethe
worldissearchingforaleftHip parttomove
thatisnotthere.
Recap
• Listsareusefulforhavingmultiplecharactersperform
thesamesetofactions.
• Eachin_together meanseverythinginthelistwill
performatthesametime.
• Foreachin_meanseverythinginthelistwillperforman
actiononerightaftertheother.
• Tofindthesub-partsofanobject,clickonthearrownext
totheobjectintheobjecttree.Makesureallofthe
charactershavethesameparts,labeledthesameway.
• WARNING:Donotaddtoomanyobjectstoyourlist,
becausedoingsowillslowyourworlddownsignificantly.