BlenderArt Magazine - 07 - Blender Materials

8/14/2019 BlenderArt Magazine - 07 - Blender Materials

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http://www.blenderart.org/


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Welcome to our 1st Anniversary Issue! Yes, that s right,we actually made it a whole year! When Gaurav and I

started this magazine, we had no idea how much wewould end up needing to learn. But learn we did, as wellas adding staff members to help out with proofing andwebsite maintenance.

It has been an eventful year for both BlenderArtMagazine as well as the Blender community itself. Wehave seen the creation and release of Elephant sDream, the addition of many needed and just plainwanted features in Blender. The Blender communitycontinues to grow at a phenomenal rate. BlenderArtMagazine reader numbers have continued to grow aswell. With each new issue, we gain a larger audience.And we appreciate all of you!

We have had an amazing response from thecommunity in terms of contributions to the magazine.While Gaurav and I could have still put out a magazinewithout all their help, it would not have been anywherenear as interesting. I d like to recognize all of ourcontributors at this point; they deserve a round ofapplause for their efforts on all our behalves.

Here they are, in no particular order, and I sure hope Ididn t forget anyone; if I did I apologize in advance.

Okay, now on to what you really want to know about -what s in this issue! Materials, lots and lots of material

information. Admit it, you want it and you need it. Youput enormous effort into your models and you know, aswell as I do, that you just have to add materials atsome point. With the addition of Nodes, or morecommonly called Noodles, whole new effects andmaterials are possible. First, we'll answer a s implequestion What are Materials? Then, we have severalNode tutorials, as well as a look at Vector Blur andRamp Shading. We also take a look at some currentEducational Resources available for Blender users.

So here we go, let s get our Blender world all coloredup!

Happy [email protected]

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www.blenderart.org Issue 7 November 2006

Sandra Gilbert

Managing Editor

Thank you all !

EDITORIAL

Enrico ValenzaJuan J. Pena

David LettierZsolt StefanClaudio MaleficoAndaurStefano SelleriClaas Eicke KuhnenDaniel LaBargeChristopher KullaKernon Dillon

ChristianGuckelsberger

Manuel PerezClaudio AndaurJos MauricioRodas R.Rogrio PerdizManuel BastioniAlessandro ProglioAntonio Di CeccaGiovanni Lanza

Martin MackinlayEd Cicka

Cory KingEarly EhlingerMariano HidalgoEdouard de MahieuSergey ProkhorchukRojaAndreia LealSchemid & ZagDiego Restrepo Pars
http://www.blenderart.org/http://www.blenderart.org/


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EDITOR/DESIGNERGauravNawani

[email protected]

[email protected]

[email protected]

PROOFERKernonDillonPhillipA.RyalsKevinC.Braun

DerekMarsh

WRITERSOlivierSarajaDanielLeBargeJohnAllieMichaelWach

COPYRIGHT2006BlenderArtMagazine,blenderartandblenderArtlogoarecopyrightofGauravNawani.IzzyandIzzylogoarecopyrightSandraGilbert.

Allproductsandcompanynamesfeaturedinthepublicationaretrademarkorregisteredtrademarksoftheirrespectiveowners.

COVERARTWiseMenbyMathiasPedersen

03

www.blenderart.org Issue7November2006

ArtisticGlowUsingBlender'sCompositorNodes

DOFUsingBlender'sCompositorNodes

CreatingRealisticEnvironmentforBGE

BlenderAndDisplacementMapping

BlenderandVectorBlur

6

8

11

24

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CONTENTS
http://www.mathiaspedersen.com/http://www.blenderart.org/


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Withthemultitudeof

toolsavailableinBlender,justaboutanymaterialcanbeconvincinglycreated.ButthereisasayinginCG,itsnotthetool,itstheartistthatcreatesart.

Thesamecanbesaidaboutmaterials.Allthelatest,newtoolsarentgoingtocreaterealisticoramazingmaterialsforyou.Youstillhavetoknowhowtousethemandmoreimportantly,youhavetoknowhowmaterialsarecreatedandwhatmakesthemconvincing.

So,insteadoffocusingontools,wearegoingtotakealookatwhatmaterialsareandwhatmakesagoodmaterial.Withthatinformation,youcanthenusealltheamazingtoolsmoreeffectively.Letsstartwithafewdefinitions.

Material:isthebasesubstanceofasurface(i.e.wood,metal,glass)

Texture:istheadjectiveofthematerial(i.e.rustyiron,brushedsteel,soiledcloth,frostedglass)

Anytimeyoucreateanewmaterial,youshouldgatherreferencematerials.Itcanbeanobjectwiththematerialyouaretryingtocreateoragoodphotographofit.Thesereferencematerialswillhelpyouvisualizewhatyouaretryingtocreate.Whengatheringreference,veryrarelywillyoufindpristinematerialswithoutsignsofwearandtearin

reallife.Therewillbedust,rust,scratches,dentsandamultitudeofothersignsthatthismaterialhasgonethroughovertheperiodoftime.Noticethesesignsofwearanddecideiftheyaresignsofmaterialortexture.

Textureattributes/qualitiescanbebrokendownbyansweringthefollowingquestions:

Whatareyou?Oftenthesimpleactofidentifyinganobjectcanhelpyouunderstandwhatkindofmaterialsyouwillbecreating.Example:afirehydranttellsyouitsshape;thatitismadeofthicksteelleftoutintheweather,andmostoftenpainted.

Whatisyouressence? TrytoidentifythemostimportantfeatureofthematerialExample:aradiatorsmostimportantfeaturemight

beitsrustyquality.Asyouidentifythemostimportantfeature,keeplookingdeeperandnoticingeachuniquefeatureofthematerial,itwillgiveyoualistoffeaturestoaddtothematerial;addingmorerealismanddepthwitheveryoneyouadd.

Whatareyoumadeof?Beforedissectingthemanylayersoftexturesthatmakeupamaterial,youneedtoidentifythebasematerial.Byidentifyingthebasematerial,youwillmoreeasilyseethedetails(textures)thatmakeitthatparticularmaterial.Example:anoldmetalsign;knowingthatitismetal,leadsyoutorealizethatsomemetalsare

pronetorusting,solookforsignsofrustandcorrosion.Isthesignpainted?(Oldpainthasatendencytochiporflakeaway,newpaintwilllookshinyandsomewhatreflective.)

Whatdoyousoundlike? Asoddasitmightsound,sometimesyoureyeswillfoolyou.Tapontheobject,whatdoesitsoundlike?Metal,glassplastic...

Whatdoyousmelllike?Oftenyoucanidentifyimportantcluesbynoticinghowtheobjectsmells.Leathersmellsdifferentthanplastic,differentmetalshavedifferentsmells.

HowcanIseeyou?

Identifythelightsource,lightingofthematerialwillplayanimportantpartinhowitisrecreated.Warmlightsourceswouldproducewarmhighlightsorhotspots,coollightstheopposite.Whengatheringyourreferencematerials,makesuretonoteina

journalormentallywhatthelightsourcewas,timeofday(ifoutside)soyoucanrecreatethematerialaccurately.

Whereareyou?Istheobjectinsideoroutside?Ifoutside,itwillbeexposedtoweather,heat,moisture.Thiswillaffectitsappearance.Newobjectsquicklylosetheirnewappearancebyacquiringdents,dings,

scratches,dustetc.Knowingwhereitislocatedwillhelpidentifythesequalities.

Whatdoyoulooklike?Nowcomesthepartwhereyoustartdescribingthetexturequalities.Thebetteryoucandescribewhatyousee,theeasieritwillbetorecreate.Somethingstolookfor:ColortextureReflectionsandshadowsIstheobjecttransparent?Istheobjectluminous?Withheat?Withoutheat?Fromanoutsidesource?Fromtheobjectitself?

Luminescentobjectscanhaveoneortwoofthesequalitiesandidentifiedas:TranslucentIridescentOpalescentFluorescentIncandescent


IzzyTalks

Blender Materials

04


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Whatdoyoufeellike?Howdoestheobjectfeel?Isitbumpyorsmooth,warmorcool,softorhard?

Tactilequalities:Temperature

BumpinessRoughnessSmoothness

Whatsyourstory?Trytoidentifythehistoryoftheobject,howhasusagecontributedtowearandtear?

Byansweringthesequestions,youwillbetterunderstandyourmaterialandhowtogoaboutrecreatingit.Itwill,ofcourse,takepracticeandlotsofobservationtomastertheseskills.Youneedtolearntotrainyourartisticeyetoreallyseewhatyouarelookingat.Soon,breakingmaterialsdownwillbeautomaticandyourmaterialswillimprovedramatically.

TheinformationforthisarticlewasparaphrasedfromOwenDemersbookDigitalTexturing&Painting(ISBN0-7357-0918-1).Ihighlyrecommendreadingthisbookforanyonewantingtotaketheirmaterialskillstothenextlevel.

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IzzyTalks

TonhasannouncedthatBlenderisslowlyheadedforanotherrelease.ItlookslikewemaygetanewreleaseintimeforChristmas.Ahostofnewfeatureshavebeenadded.Releaselogshavealready

beenwrittenforthefollowingfeatures;AnimationWalkCycleModifiersProxyObjects,forlocalcontroloverreferenceddatafromLibraries

RenderingRenderfeatures:tangentsandnormalmapsIrregularShadowBuffersShadowbuffer,HalfwayaverageRenderBaking

Compositing

MatteNodesMatteNodes,tutorial

Linkstothefollowingfeaturedocumentationwillbepostedassoonastheyarefinished.ModelingModifierStackupgradesSculptmodeling,multi-resolutionMeshandRetopoFluidDynamicssupportinganimatedObjectsMulti-levelUVediting

Testingbuildscanbedownloadedfromwww.blenderbuilds.com.

Anewblenderbookhasbeenannouncedandtheyarelookingforcontributorstohelpwithcompletionofthebook.Ifyouareinterestedinhelping,contactRolandHessatblenderbasicsatharkymandotcom.

EditorRolandHesswrites:Thebookcanbeusedasafullintroductionto3DartandBlender,orasareferenceforpeoplealreadyexperiencedwithotherapplications.Eachchapterconsistsofatutorialsectionandtheorysection,meanttospeaktonewusersandgivethemagroundinginthesolidbasicsneededtosucceedwithBlender.

Blender News
http://www.blenderbuilds.com/http://mediawiki.blender.org/index.php/Tutorials/Matte_nodeshttp://mediawiki.blender.org/index.php/Manual/Compositing_Nodes#Matte_Nodeshttp://www.blender.org/cms/Render_Baking.827.0.htmlhttp://www.blender.org/cms/Shadow_buffer__Halfway.786.0.htmlhttp://www.blender.org/cms/Irregular_Shadow_Buffe.785.0.htmlhttp://www.blender.org/cms/New_Render_features.774.0.htmlhttp://www.blender.org/cms/Proxy_Objects.824.0.htmlhttp://www.blender.org/cms/Walk_Cycle_Modifiers.821.0.htmlhttp://www.blender.org/cms/Newsitem.607+M51379558c2b.0.htmlhttp://www.blenderart.org/


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ArtisticGlowisaneffectthatisacomponentofalmosteverymajorphotoeditingsoftwarepackage.Blenderhastheabilitytorecreatethiseffect,butwithmorecontrolandmorefinesse,becauseoftheuniquenodebasedsysteminwhichglowcanbeapplied.Therearemanywaysofaddingglow,includingusingotherprogramssuchasGIMPorBlender'sGlowpluginforthesequencer.Wearegoingtotakealookathowto

addglowusingBlendersCompositorNodes.Prerequisites

ThisarticleassumesthatyouhaveascenewhichcontainssomeareasofcontrastandthatyouknowyourwayaroundBlender.Itissafetosaythatthisisforintermediatetoadvancedusers.

GettingStarted

TocreateGlowinBlenderweneedtodoseveralthings.First,enabletheCompositor.Todothis,pleasereferenceImage1whichshowstheDoCompositeenabled.YoucanfindtheseintheRenderButtons(F10)undertheAnimPanel.

NowwearereadytobegincompositingourscenewithGlow.OpenuptheNodeEditorWindowandbydefaultitshouldhaveaRenderLayersnodeconnectedtotwooutputnodes,ViewerandCompositor.ItisagoodideatoopenuptheUVImageEditorWindowandswitchtheimagetoViewerNodetogetalargerviewoftheVieweroutput.Thishelpswithfinetuning.

Let'sfirsttakealookattheimageasrenderedoriginally.ObviouslythesceneissetupwithareasofstrongcontrasttohelpwithapplyingrealisticSpecularGlowinsteadofjustIntensityGlow.Wewillbasetheglowonthiscolorvalue,andthenmixtheglowmaskontoptocompletetheGloweffect.

CreatingtheGlowMask

TocreatetheGlowMaskweneedtohighlightthedetailsintheimage.TodothisIliketofirstuseaSharpenFilter.AddaFilternodeandhookuptheImageinputtotheImageoutputoftheRenderLayersnode.HookingupaViewernodetotheoutputImageoftheFilternodewilldisplaytheresultsofthefiltereffect.WewillbeusingFilterTypeSharpen,astestshaveshownittobethebestforenhancingthedetailsoftheimage,althoughitcreatesmanyartifactswhichwewillhavetodealwithlater.

Nowweneedtoisolateonlythespecularareas,oratleasttheareaswiththemostintensity,whichtypicallyaretheareasofspecularity.Todothiswe

needtomodifytheRGBcolorvalues.ThenodeforthisistheRGBCurvesnode.HooktheImageoutputoftheFilternodeuptotheImageinputoftheRGBCurvesnode.

Thecurverequirestuningaccordingtoyourscene.Youwantapicturethatexhibitsthemostcontrastbetweendarknessandlightness.ToadjustthiscurveusetheCombinecurvetabandselectlocationsonthecurveandmovethem.HookingupaViewernodetotheImageoutputhelps.

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3DWorkshop-ArtisticGlowUsingBlender'sCompositorNodes

Artistic Glow Using Blender'sCompositor Nodes

-byDanielLaBarge

Image1.Enablingnodecompositor

Image2.Examplesceneindifferentsettings


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Aftertheoutputhasenoughcontrastyounowneedtoconvertthistoblackandwhite.Forthisstepwe'llneedtoaddanRGBtoBWConverternode.HookuptheImageoutputoftheRGBCurvesnodetotheImageinputoftheRGBtoBWConverternodeandthenhookuptheoutputtoa

Viewernodetoseetheresults.

We'realmostthere,butasyoucansee,themaskisverypixelatedandhaslotsofartifacts.Tofixthis,weneedtoblurit.

AddaBlurnode,connectingtheValueoutputoftheRGBtoBWConverternodetotheImageinputoftheBlurnode.UseafiltertypeofQuadraticandapixelradius(XandYsettings)appropriateforthescene.EnablingGammablurringalsohelps.HookupaViewernodetotheoutputtoseethefinalglowmask.

ApplyingtheGlowMask

ToapplytheGlowMasktotheImageweneedaMixernode.ThisnodetakestheImageinputsandthenmixesthetwoinputstogetherbasedonaFilterType.InmostcasesyouwillwanttousetheAddtype.Thiswillperformapixel-by-pixeladditionbetweenthetwocolorvaluesoftheImageinputs.

FinalTouches

YoucannowhookupaViewernodeandaCompositornodetotheImageoutputoftheMixernode.YouwillseethecombinedimageswiththeGloweffect.Ifallwentcorrectly,youshouldnow

haveapicturethathasintensityalongalloftheedgesthatexhibitspecularityorintenselightdiffusion.

YoucanusetheFactorsettingintheMixernodetocontrolthemixingofthetwoImageinputs.Finetuningmayberequired,andtheextraViewernodeswillhelpmaketuningeasy.

Belowyouwillseetheoutputsettingsforthe

differentvaluesateachstageinthecomposition.AlsoincludedistheschematicfortheGlownodesetup.

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Image3TheNoodlesfor'SoftGlow'

ThisschematicshowstheGlownodesinsideaGroupnodecalledGlow.Thisisnotrequiredforthefinal

output.YoushouldfindareferenceBlenderfileincludedwiththisissuetotrackandtraceaworkingexampleofthissetup.

Besuretovisithttp://www.idstudios.orgformore

informationoncreatingGlowandotherspecialeffect

nodes.

NOTE

NOTE:ThisarticlewascreatedusingaCVSversionofBlenderandsomefeaturesshowninscreenshotsmaynotbeavailableatthecurrentpublicationofthisarticle.ThroughthemainBlenderreleasehowever,theeffectdescribedherecanbeusedinthecurrentBlenderrelease.

NOTE
http://%20http//www.idstudios.orghttp://www.blenderart.org/


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DepthofField(DOF)isaverypopulareffecttobesimulatedincomputergeneratedimageryasitaddstotheoverallrealismofanimage.True,DOFasyoureyeperceivesitisnotyetpossiblewithBlender,butaveryclosesimulationofforegroundandbackgroundblurcanbeachieved.Wewillbelookingatonemethod,usingBlender'sbuiltinCompositorNodes.

PrerequisitesThisarticleassumesthatyouhaveascenewhichexhibitsanecessityforDOFandthatyouknowyourwayaroundBlender.Itissafetosaythatthisisforintermediatetoadvancedusers..

GettingStarted

TocreateDepthofFieldinBlenderweneedtodoseveralthings.First,enabletheCompositorandpasstheZChannel(Blender'sdepthchannel)totheCompositor.TodothispleasereferenceImage1whichshowstheDoCompositeenabledandtheZPassenabled.YoucanfindtheseintheRender

Buttons(F10)underAnimPanelandRenderLayersPanel.

NowwearereadytobegincompositingourscenewithDOF.OpenuptheNodeEditorWindow.Bydefault,itshouldhaveaRenderLayersnodeconnectedtotwooutputnodes,ViewerandCompositor.ItisprobablyagoodideatoopenuptheUVImageEditorWindowandswitchtheimagetoViewerNodetogetalargerviewoftheViewer

output.Thishelpswithfinetuning.

Let'stakealookattheimageasrenderedoriginally.Obviouslythesceneissetupandthe

elementsarearrangedtoexhibitgoodDOF.Wewillbeblurringthecolorvaluesusingthedepthchannel.

Nowlet'slookattheZChannel,deliveredintheZPasstotheCompositor.Todothis,addanewViewerandconnecttheZinputtotheZoutputoftheRenderLayernode.IntheUVImageEditorclickontheiconthatshowstheZvalue.Thisiswhatthedepthvalueslooklikeforthescene.

MappingtheZChannel

Thesevalues,althoughappearingcorrect,won'tactuallycreateaproperDOFeffectifsenttotheBlurFilternodeastheSizeinput.Tofixthis,weneedanothernodecalledMapValue.Thisnodewilltakethevaluesasinputsandadjustthem.TheValueinputshouldbeconnectedtotheZoutputoftheRenderLayernode.Thereareseveralsettings,includingclampfunctions,tosettheMinimumvaluerangeandtheMaximumvaluerange.Thetwosettingswewilluseare

OffsetandSize.Offset,inmyexperience,hasalwaysbeenanegativevalueanditappearstobetheBlendergridunitsfromthecameratothefocus.Size

appearstobeagradientfilterthatcontrolstheabruptnessofthetransitionbetweensharpnessandblurrinesswhenusedwiththeBlurnode.

Positivevalueisusedforbackgroundblurandanegativevalueisusedforforegroundblur.Thecloser

thevalueisto0,thesofterthegradient.Negativevaluesaretypicallyverysmall,usuallynomorethan-0.250.YoucantakealookatthenewZchanneloutputbyhookingupaViewernodetotheValueoutputandlookingattheZchannelintheUVImageEditor.

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3DWorkshop-DepthOfFieldUsingBlender'sCompositorNodes

DepthOfFieldUsingBlender'sCompositorNodes

-byDanielLaBarge

Image1EnablingnodecompositorandZpass

Image2.Examplesceneindifferentsettings


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CreatetwoMapValuenodesandhookthemuptotheZoutputoftheRenderLayersnode.SetOffsettoanegativevalue,approximatelythesamenumberofgridunitsfromcameratofocuspoint.TheOffsetvaluesshouldbeidenticalorveryclose.TheSizevalueforoneshouldbeanegative

valuebetween-0.050and-0.250,andtheothershouldbeapositivevaluebetween0.250and1.000.

BlurringtheImage

Nextwe'llneedtousethesevaluestoblurtheimage.ThisiswheretheBlurnodecomesintoplay.AddtwoBlurnodesandhookuptheImageinputtotheImageoutputoftheRenderLayernode.HookuptheSizeinputtotheValueoutputoftheMapValuenode.RepeatfortheotherMapValuenode.TheBlurnodehasseveralsettings.IhavefoundthatQuadraticfiltertypeandGammaenabledworkbest.TheXandYsettingscontroltheradiusoftheblureffectinpixels.Formorebluruseahighernumber.IfyouhookupaViewernodetotheImageoutputyouwillseetheresultsoftheDOFandyoucanedittheMapValuesaccordingly.TheoneViewernodewillshowtheforegroundblurandtheotherwillshowthebackgroundblur.

Nowwehavethetwoimagesblurredbutweneedtheforegroundandbackgroundblurcombined.Thereareseveralwaystodothisbuttheproperwayistouseanotherspecialtynode.ThisnodeiscalledZCombine.HookuptheImageoutputofoneBlurnodetothefirstImageinputoftheZCombinenode,andthenhookuptheother

correspondingMapValue'sValueoutputtotheZinputoftheZCombinenode.

RepeatfortheotherBlurnodeandMapValuenode.NoticethatthecorrespondingImageinputgoestotheoppositeValueoutputoftheMapValuenode.Thisisimportanttoproperlycombinethetwoimageswithoutartifacts.

FinalTouches

YoucannowhookupaViewernodeandaCompositornodetotheImageoutputoftheZCombinenodeandyouwillseethecombinedimageswhichwillshowtheDOFeffect.Ifallwentcorrectlyyoushouldnowhaveapicturethathasforegroundblurandbackgroundblurwiththecenterrangesharpandinfocus.Finetuningmayberequired,andtheextraViewernodeswillhelpmaketuningeasy.

Belowyouwillseetheoutputsettingsforthedifferentvaluesateachstageinthecomposition.AlsoincludedistheschematicfortheDOFnodesetup.

WhatAboutAnimations?

AnimatingDOFwithCompositornodesisalittletoolengthytoexplain,buttheideahitmeoneday

whiletryingtomixvalues.ThesecrettoanimatedDOFistomixkeyframedMapValuesalongaTimenode.AslongasyouhavetheDOFsetforaparticularframeyoucancontroltheMixingusingthecurveinaTimenode.ThiscangetreallybulkyandIcan'twaitfortheBlenderdeveloperstocreateaninputfortheMapValueOffset,butuntilthatfeatureisimplementedyoucanusethereferenceschematicbelow.

YoushouldfindareferenceBlenderfileincluded

withthisissuetotrackandtraceaworkingexampleofthissetup.

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Image3TheNoodlesfor'DepthOfField'

ThisschematiccontainsacustomGroupnodeforaddingDOFtothefinalcomposition,andisnotrequiredforthefinaloutput.

NOTE


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SpecialthanksgotoCehukenofBlenderArtistswhohelpedexplainthenodesetupforasimilarDOFapproachtotheBlendercommunity.

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Image4DOFNoodlesforAnimation

I'm17andhavebeenafreelancesinceIwas15doingeverythingfromwebsitedesigntographicdesign...Nothingtooimportant!Artist[www.idstudios.org]Writer[www.blendernation.com]Developer[www.monsterweb.net]
http://www.idstudios.org/http://www.blendernation.com/http://www.monsterweb.net/http://www.blenderart.org/


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Blender'sgameengineisfairlysimpleassuchthingsgo,butwithalittlehardworkonecanstillcreaterelativelyrealisticgames.Inthisarticle,ImgoingtotrytohelpyoulearnhowyoucanusethesefeaturestomakeyourBlendergamesasrealisticaspossible.

Planning

Beforeyoubeginmakingagamescene,youshouldhaveasetideainyourmindofwhatyouwantthescenetobe.Decide:Whatdoesthearealooklike?Whatistheplayermeanttoaccomplishhere?Whatisthearea'srealpurpose?(i.e.-iftheareareallyexisted,whatpurposewoulditserve?)

Onceyou'veworkedouttheanswerstothesequestions,yourereadytogettoworkonyourscene.Somepeopleprefertomakesketchesoftheirgamescenesaheadoftime,butIusuallyjustgostraighttoBlender.

Whendesigningyourscene,rememberthatthe

playerneedstobefencedinsomehow.Nomatterwhat,peoplealwaysseemtowanttogobeyondtheconfinesofyourgamemap,andyou'llneedtocomeupwithagoodexcuseastowhytheycan't.Preventingtheplayerfromleavingthemainpartofthesceneisnotenough,youmustalsoconvinceherthatshedoesnotwanttoleaveit.

Themostpopularformsofenvironmentboundsareasfollows:

Islandisusuallywhatitsoundslike.Thisisanextremelypopularmethodofdefiningsceneboundaries:simplyputinavastoceanandpeopleimmediatelyassumetheycannottraverseit.InmygameTheVoyageoftheGoldenArm,IusedtheIslandtechniqueinadesertaswell:oneofthegame'slevelstakesplaceonalargehill,whichissurroundedonallsidesbyadesertwasteland.Theeffectisthesamethoughtheoceanisanoceanofsandandnotwater.Anothervariationisthebutte,inwhichthegameareaisatopahighcliff,surroundedonallsidesbyverticaldrops.Islandscanalsobecombinedwithinvisiblewalls,topreventthemostdeterminedplayersfromwalkingtoofarintotheocean.

Canyonisanenvironmentwhichissurroundedonallsidesbyinsurmountablewalls.Preferably,theseshouldbehighwalls:shortfencestendtofrustratepeople,asinreallifetheywouldsimplystepoverthem.ThebestCanyonwallsshouldbemuchhigherthanthegamecharacter'sheight.

TunnelwaspopularizedingameslikeDoom,wherealltheactiontakesplaceinsideclosed-incorridors.Tunnelshavefallenoutoffavorbecausetheyallowforverylittlevarietyinyourgamescenery.

DeathZoneistheleastrecommendedoftheacceptableboundaries.Adeathzoneisanareaoutsidethemaingameenvironmentwhichcausesinstantdeathifentered.AnexampleisthedarkcavernsofthetextadventureZork,inwhich

waywardplayersaredevouredbygrues.Thesearenotrecommendedbecausetheyseemunfairtotheplayer,andcostlives.Ifyoudecidetouseadeathzone,makesurethattheplayeriswell-informedofthearea'sstatus.Nothingismorefrustratingthanasurprisedeathzone.

Inthisarticle,wewillbeworkingtowardarealisticIslandscene.I'mnotexpectingyoutofollowalongwiththetutorial,simplyreaditandlookatthestepsItaketoimprovetheisland'srealism.Learnthesetechniques,andyou'llhaveallthetoolsyouneedtoworkonyourowncreations.

Here'sthelittleislandwe'llbeimproving:

Inalllikelihood,yourgameartisnotasbadasthis,

butthisdoesdemonstratequiteafewoftheproblemsI'veseeninbeginnerart.We'llusetechniquesofshading,texturing,andmodelingtomakethisislandmorerealistic.

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3DWorkshop-CreatingRealisticEnvironmentForTheBlenderGameEngine

CreatingRealisticEnvironmentForTheBlenderGameEngine

-byJhonAllie

Image1Differentenvironmentbounds

Image2.TheIslandscene


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Shading

Shadingishowwesimulatelightinginthegameengine.Shadingdefineslightanddarknessonyourmodels,andisoneofthemostimportanttoolsforaddingrealism.

Theeasiestwaytoshadeyourmodelsistomakethemlight-sensitive.Selectthemodelyouwanttomakelight-sensitive,pressFtoenterUVface-selectmode,andpressWtoopentheSpecialsmenu.(It'simportanttomemorizehotkeys,especiallyunintuitiveoneslikethisone.)SelectLightfromtheSpecialsmenu.

Ourhorriblelittleislandismorerealisticalready!Realislandsaren'tfacetedlikethis,though.

Nowthatit'ssmooth,theislandlooksmuchmore real.Here'swhatitwouldlooklikeifwesetLight

foralltheobjects:

Lightsensitivityisnotagoodsolutionforinanimateobjects,though,becauseiteatsalotofprocessorpower.

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Image3EnablingLightSensitivity

Image4Light-sensitiveisland)

Image5EnablingSmoothRendering

Image6Smoothed,light-sensitiveisland

Image7Real-timeshading


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Blenderhasanotherlight-simulatingfeature,though,whichsimulatesthelightonlyonce,thenbakesittotheobject'svertexcolors.Simplyselecttheobjectyouwishtoapplytheeffectto,andclicktheVertColbakebuttonintheEditButtons.

TheVertColbakingoptionisgreatwhenyou'reinahurry,buttheresulttendstobekindofdark.Addingmorelampscanhelpremedythisproblem,asthevaluesarecalculatedfromthescene'slamps.Here'sthesamescene,withvertexcolorsbakedfromtwolamps:

Thelastshadingmethodistopaintthevertexcolorsbyhand.Thisismypreferredmethodbecauseitgivesmuchmorecontrol,butitdoestakemuchmoreeffort.Ifyoudecidetoshadeyourmodelsthisway,makesurethatyoutrytosimulatethelightcorrectly.Trytorememberwherethelightiscomingfrom,andshadeyourmodels

accordingly.

Ingeneral,whenpaintingroundedmodelslikeSuzanne,IusetheVertexPaintbrush.Withangularmodelssuchasbuildings,IselectthefacesindividuallyandfillthemusingtheSetVertColbutton.Sometimes,I'llalsoaddaslightgradientwithVertexPaint.

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Image8BakingVertexColorShading

Image10BakedShadingwithTwoLamps

Image11RememberLightDirections!

Image12SettingVertexColorsByHandImage9BakedShading


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Tolearnhowtoshadewell,payattentiontoyoursurroundings.Trytolearnwhichareasarebrightestordarkest.YoumaywanttorunsomeRadiosityorAmbientOcclusionsimulationsinBlenderforresearch.(Don'tuseRadiosityoutputinthegameengine,though-themodelsitgeneratesareextremelycomplex!)

Carefuluseofvertexcolorscandowondersforyourgameenvironment.Intherealworld,oneneverencountersanobjectwithoutshading,soit'simportanttokeepthisinmindwhenmakingyourgameenvironments.Shadeeverything,nomatterhowsmallitis!

Modeling

Nowwe'lllookathowtoimproveyourgamemodeling.Let'stakealookatthewiremeshofouruglylittleisland.

Whatappearstobeasimplesceneisnotverysimplefromtheenginespoint-of-view!TheislandismadefromacomplexUVsphere,themonkeyheadhasbeensubsurfed,andthetreesandbuildingcolumnsarebothmadefromcylindersat

thedefaultsetting,32.It'simportanttorememberherethatthoughBlendercanbeusedtomakegames,itsprimarypurposeiscreatingrenderedimagery.

ThisiswhytherearemanyBlenderfeatureswhichareincompatiblewiththegameengine,andmanymorewhichthoughcompatibleshouldnotbeused.

Subsurfisanexampleofthelatter.Thoughsubsurf

isnowcompatiblewiththeGE,itshouldnotbeusedongamemodels.Theintentionofgamemodelingistocreatelow-polymodelswhichareassimpleaspossible.Subsurfworksbyturningeveryfaceofyourmodelintomanysmallerfaces,andisthereforeanextremelycounterproductivemethodwhenitcomestothegameengine.

Whenworkinginthegameengine,yourintentionshouldbetokeepyourmodelsassimpleas

possible:avoidusinganythingwhichmakesyourmodelsmorecomplicated.

Let'sgetstartedonourgamemodelsbyimprovingthetemple.

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Image13Hand-paintedgradients

Image14Darkeningcornerscanimproverealism

Image16TempleMesh

Image15IslandMesh


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We'llfixthecolumnsfirst.Thecolumns,asyoucanseeinthisimage,appeartobealmostasolidcolor.Whenyourgamemodelslooklikethis,itsafairbetyou'veusedtoomanypolys.Thirty-two,thedefaultsettingforcylinders,isoverkillforthegameengine.Tenverticesshouldbeenough,you

canprobablygetawaywithonly7,andyoushouldneverneedmorethan15or20.

We'llcreateanewcolumnmodelandsetitto10insteadof32.Asyoucansee,acolumnwith10verticesstilllooksveryround.It'snotimportanttomakeeverythinginyourgamehaveaperfectshape.Peopleexpectgameobjectstohaveslightly

jaggedshapes,andthemindcaneasilyfilloutthemodeltoitscorrectshape.

Thetrickistofindthehappymediumbetweentoomanyverticesandnotenough.Tenisjustaboutrightforthiscolumn.Forabiggercolumn,20mightbemoreappropriate.Forverysmallobjects,youmaywanttoreducethenumbertofouroreventhree.Avoid6-or8-sidedcylinders,though:themindisfamiliarwiththeseshapesandyourplayermayhaveahardtimeignoringthem.

Low-polymodelingalsomeansremovinganythingthatisnotneeded,whichincludesfacesthatcan'tbeseen.Thiscolumnhasfacesoneitherendwhichcannotbeseen.Clickthefaceselection

button,selectthehiddenfacesatbothendswiththeB-keyselectmode,presstheDeletekey,andclickFaces.

Remembertocheckforthesefaces!They'reverycommon,andtheydotendtoaddup.Unimportant

astheymayseem,havinglargenumbersofthemcanleadtoagameslowdown.

Considerthis:Eachcolumnhas10facesoneachend,noneofwhicharevisibletotheplayer.Withallfourofthebuilding'scolumns,thereare80extrafaces!Alwaysremembertocheckforandeliminategameenginewaste.

Now,let'stakealookatthetemplesteps.

Sometimes,weneedtodividefacesintosmallerfacesinordertocreatesomething.OnewaytocreatemorefacesistousetheSubdividetool,butthistooldivideseveryfaceintolotsofsmallerfaces,creatingalotofunnecessaryextrafacesandaddingtogameenginewaste.AmuchbetteroptionistousetheKnifetool.

15



Image17SettingnumberofverticesforacylinderImage20Carelesslymadetemplesteps

Image19DeletingHiddenFacesImage18Newcolumnfrom10-vertexcylinder

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TheKnifetool'spurposeistoaddextraverticestoanedge.Thiswillallowyoutodivideupyourmodel'sfacesonlyasmuchastheyneedtobedivided,andpreventgameenginewaste.TousetheKnifetool,selecttheedgesyouwishtooperateonandpressShift+K.TheKnifemenuwill

appear.SelectExactLinefornow,andthendrawalinethroughyouredgesandpressEnter.

Ourfaceisnowcutinhalf,andreadytobeextrudedintosteps!IfwehadusedSubdivide,thefacewouldhavebeendividedintofoursections,farmorethanweactuallyneed.Nowwecanextrudethefaceandfinishcreatingourstaircase.

Theresultwillbeabaseforthetemplewithfewerthanhalfthefacesoftheoriginal.Don'tforgettodeletetheundersideofthetemple'sbase:itwillbe

underground,sothereisnoreasontosaveit.

Thetempleisprettygoodnow!Let'sleaveitaloneandtakealookatthoseobnoxious

palmtrees.

Thisisnotapalmtree.Thisisacartoonofapalmtree,andaveryhigh-polyoneatthat.Thetrunk,likethecolumnsonthebuilding,isa32-vertexcylinder.Itisabsurdlystraight:thenaturalworldsimplydoesnothavesuchstraightlines.Ourfirstorderofbusinesswillbetoimprovethistrunk.

Adda7-vertextubeandresizeituntilit'slong,straight,andnarrow.ScalingitsmallthenenlargingitontheZaxisshouldwork.(Makeahabitofusingtubesinplaceofcylinderswhenneitherendwillbevisible.Inthiscase,oneendofthetrunkwillbebelowground,andtheotherwillbeaboveplayers'heads.Neitherwillbeseen,soyoucanuseatubeinplaceofacylinderandsaveyourselfsomepolys.)Onceyourtubeisready,usetheKnifetooltosliceitupafewtimes,thengiveitasubtlebend.Scaleitdownabittowardtheupperend.

Thistrunkisnotonlymore realistic,ithasfewerpolysaswell!

Tocreatetheleaves,addaplaneandextrudeoncefromeachend:

Now,selectyourendsoneatatime,pressW,andselectMerge.

Theresultwillbeaplanewithatriangularfaceattachedateachend.NowusetheKnifetooltodividetheplaneverticallydownthe

middle.Selectthenewverticesandmovethemupsothattheleafwillcurveinthemiddle.

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Image21UsingtheKnifetool

Image25UsingtheMergetool,Step2

Image24CreatingPalmLeaves,Step1Image22PalmTree

Image23Newtreemesh

Image26CreatingPalmLeaves,Step3

Image27CompletedPalmLeafmesh

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Thisisourbasicleafmodel.Youcantweakitalittleifyoulike.Itmaynotlookverymuchlikeapalmleafyet,butthetexturewillimprovethat.Itshouldbenotedthatsinceleavesareclosetobeingflat,itisperfectlyacceptable,andrecommended,toportraythemwithplane-based

objectslikethisone.Inthegameengine,trytoportraycomplexitythroughtexturingratherthanmodeling,wheneverpossible.Thispalmleafdoesnotneedtobeverycomplex,becauseitstruerealismwillbeappliedthroughitstexture.Wewillbecoveringtexturingshortly,butI'lljumpahead

justamomenttoshowyouwhatthecompletedpalmtreelookslike.

Lookhowgrotesquetheoriginalpalmtreelooks,nowthatit'sshownbesideonethat'ssorealistic!It'salwaysworthgoingtheextrafewstepstomakeyourgamelookgood.Don'tbeafraidtoinvesttheextratime-inalllikelihood,yourgamewillnotonlylookbetter,butitmayrunfasteraswell.

ThelargeSuzanneheadIwillsimplydelete.Alwaystrytomakeyourownmodels:they'llmorecloselyresembleyourownstyle,andtheymayevenbemorecompatiblewiththegameengine.Thereisnoneedforagiantstonemonkeyheadhere,though,sothereisnoreasontoincludeit.If

youaremakingaBlender-themedgame,however,incorporatingSuzanneisencouraged!

Let'sspendsometimerebuildingtheislanditself.Atthemomentit'sjustabigroundthing.That'sfineifyourgameisaboutTheFarSide,butifyou'reaimingforsomethingmorerealistic,wehavetoimproveitabit.

ThisisonetimewhenIconsidertheuseofSubdividetobejustified.Addaplane,scaleitupabit,andsubdivideitafewtimes.

Theillustrationshowstheplaneafterfoursubdivisions.Thatshouldbeenough.Nowpress[OKey]oropenthemenutoactivateProportionalFalloffeditingmode.

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Image28Original&ImprovedPalmTrees

Image30Subdividedplane

Image29Subdividebutton Image31ProportionalFalloffMenu

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Nowselectafewverticesandbeginmovingthem.Youwillseethatnearbyverticeswillbeginfollowingthemalong.Youcanmovethemousewheeltoadjusttheextentoftheeffect.Pullupthegroundtomakesomesubtlehills.IpressedZwhiletranslatingtolockmovementtothe

verticalaxis.

Yourcompletedislandshouldlooksomethinglikethis:Notethatthehighestpointsoftheislandareinthe

middle,andtheedgesslopedownwardintotheocean.Thisisactuallyaprettygoodislandmodel,althoughthesteepslopesmightmakeitdifficulttonavigate.It'salsoworthnotingthatsomevideo

cards(manyIntelchipsets,especially)experienceastrangeproblemwhichcauseslandscapeslikethesetosquirm.Ifyouexperiencethisproblem,simplyselecttheentiremodelineditmodeandpressControl+Ttotriangulatethemesh.

Onelastthingtolookatbeforewemoveontotexturing-theSkybox.

Asyoucansee,thecloudtextureisliterally

mappedontoagiantbox.Somepeoplecanmakethistechniqueworkverywell,butI'vefoundthat

it'sextremelydifficulttodisguisethefactthatit'sahugebox.Iprefertousetubes,spheres,orplanestocreateclouds.Theroundededgeofthetubeorsphereismoresubtlethanacube'srightangles,andthereforehardertospotandeasiertohide.

Thetubeisagreatwaytomakeclouds.Itrequiresabitofextraworkonyourparttomakeitsspecialtexture,buttheresultisworththetrouble.Yousimplyneedtocreateagoodcloudtexture,andthenuseyourpaintingprogramtoaddacolor-to-transparencygradientskycoloratthetop,toachievearesultlikethis:

Thenmapthetextureontothetube,andsetBlender'sworldcolortothesameskycolorastheimage.Theresult:Prettynifty,eh?NotonlydoestheTubemethodcreatenice,

seamlesscloudsaroundthehorizon,butithidesthecornersofthegroundoroceanplaneaswell.AnicewaytoanimateTubecloudsistomakethe

tuberotateveryslowly.Theeffectissubtlebuteffective.

TheSphereskymethodworksbasicallythesameasTube,butIfindthatit'shardertomaptexturesontoasphere,andtheyhavemorepolysaswell.TheadvantageofSphereisthatitallowscloudstobeonallsidesofthescene.

ThePlanemethodisfairlysimple.Youcansimplyaddaplaneabovethesceneandcloud-textureit.

WhenIusethismethod,Ioftencreateanobjectliketheoneontheleft,andvertexpaintitasseenontheright:

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Image32UsingProportionalFallofftoMakeHills

Image36TubeClouds

Image34UglySkybox

Image35CloudTextureforTube

Image33NewIslandMesh

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I

thenmapitwithablack-and-whitecloudtexture,andsetittoAddinFace-Selectmode.Thesesettingscreatesimplecloudswhichfade

outaroundtheedges.TheyhavetheappearanceofallAdd-renderedobjects,butyoucanalwayschangethatbycreatingatexturedesignedtobeopaqueinstead.

Notethatplane-basedcloudsappearonlyabove,

whereasTubecloudsappearonlyatthehorizon.Spherecanbeconsideredthebestofboth

worlds,butit'sabithardertoworkwith.However,someperseverancecangetyouaniceeffect.

Onelastwordaboutclouds:you'llprobably

experiencesomeproblemsduetothefactthatfacesare,bydefault,visibleononesidebutnottheother.You'llhavetorecalculatethecloudobject'snormalstomakeitvisiblefromtheinside.Ineditmode,simplyselectallitsverticesandpressCtrl+Shift+N.Thisshouldfixtheproblem.

FinalthoughtsaboutgamemodelingTrytousethesmallestnumberofpolyspossible.Smallobjectscanoftengetawaywithvery,veryfew.Ahandleonadoor,forexample,mightbemadeoutofathree-sidedtube!Largeobjectsoftenneedahigher-resolutionmesh,though:don'tbeafraidtogivethemwhattheyneed.Resistthetemptationtocreatehigh-polymodelsandthendecimatethem.Decimationcreatesugly,complicatedmesheswhicharehardtotextureandextremelydifficulttoanimate.

TheDecimatedversionoftheHigh-PolySuzanneisnotequaltotheoriginal.Everythingwillbe

easierifyoustartoutmodelinglow-polyinthefirst

place.Don'ttrytocheatbymodelinghigh-polyanddecimatingitlater.

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Image37PlanarCloudObjectmeshandvertexcolors

Image41WhyDecimationisNotYourFriend

Image39PlanarClouds

Image40SphereClouds

Image38EnablingAddRendering

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TexturingThoughshadingandmodelingarebothcrucialtocreatingrealisticgameenvironments,yourmostpowerfulweaponbyfaristexturing.Itdoesnotmatterhowperfectyourmodelsareorhowwellthey'reshaded:iftheyhavebadtextures,theywill

lookterrible!Texturingisthefinalword,italonemakesorbreaksyourenvironment.

Imakenearlyallofmytexturesmyself.ItakephotographsofinterestingsurfacesandconvertthemintotexturesusingGimp.Thereisnoalternativetophotographictextureswhenonewishestoachieverealism.

Themostimportantthingtorememberwhencreatingtexturesistomakethemseamless.YoucandothisquiteeasilyinGimpbynavigatingtoFilters->Map->MakeSeamlessinthemenus.This

effectisnotperfect,butitdoeshidetheseamsinyourtexturesquitenicely.Youmaystillneedtododge/burnbyhandalittletoensureauniformshade,butforthemostpart,makingtexturesis

painless.

I'mnotgoingtogiveawholetexture-creationtutorialhere.Sufficeitto

say,texture-makingconsistsmostlyofalteringphotographsuntiltheycanberepeatedwithoutobviousrepetition.

Ifyoulookattheisland,youllseethatitstextureisobviouslyrepeating.Thegroundtexturecontainsastronglydefinedpurplespot,whichisrepeated

againandagainforacrazypolka-doteffect.

Onequickwaytoremedythisistoswitchfromthedefault1/1UVtexturingsettingtoadifferent

setting.IntheUVfaceselectmode,pressAtoselectallthefaces,andpressUtochooseamappingoption.Blender2.42adeliversahordeofnewUVmappingoptions,andI'lladmitthatI'mnotfamiliarwithallofthemyet!I'vefound,however,thatforrelativelyflatobjectslikeourisland,the

projectfromviewoptionworksnicely.Selectitwhileviewingtheislandfromabove,thensimplyscaletheentireUVmapupanddownintheUVwindowuntilyouliketheresult.

Asyoucansee,theisland'sappearanceisalready

drasticallyimproved.Thepurplespots,thoughnotgone,arenotsuchabigproblemanymore.You

maystillwanttotrytochangetheirtone,though,whichcanbeeasilyachievedthroughsomesmallGimptweaks.Theeasiest,andoftenmosteffective,methodistosimplyselectagreenishcolor,thenbrushoverthepurpleareaswiththebrushtoolsetinColormode.

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Image45ImprovedUVmapping

Image43Non-seamlessandseamlesstextures

Image44SelectingaUVmappingoptionImage42MakingatextureSeamlessinGimp

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Theislandlooksalotbetternowthattheuglypurplespotshavebeeneliminated...butbeforeitcanlookrealistic,weneedafewmoredifferent

texturesonthere!Let'sstartbyaddingabeachwhichrunsaroundtheedge.

Firstcreateasandtexture,andthencreateasecondtexturewhichblendsthesandtextureintothegrasstexture.Itshouldlooksomethinglikethis:

I'mgoingtoassumeherethatyouhavesufficientknowledgeofGimp(orPhotoshop)todothis.Thoughastep-by-stepguidetocreatingtextures

wouldbeuseful,itisbeyondthescopeofthisarticle.

Now,mapyourplainsandtexture(withoutgrass)ontothefacesaroundtheedgeoftheisland(See

Image49).

Next,isthetime-consumingpart.Maptheblendedtexturewemadetothefacesinbetweenthegrassfacesandsandfaces.Ifindthatthe1/1settingworksbestforthis.Gettingthisperfectcantakeawhile,sobepreparedtospendagooddealoftimeonit.

21



Image49IslandwithTwoTextures

Image48Grass->SandTexture

Image46EliminatingColorVariationinTextures

Image47IslandwithImprovedTexturesImage50TwoTexturesSmoothlyBlended

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3D W k h


22/46

LookathowrealistictheislandisnowcomparedtothewayitlookedattheendoftheModeling

section!Thisshowshowimportanttexturesaretoyourscenery.Wecouldcallthisfinishednow,butlet'sapplyafewmorechangesfirst.

First,let'sfixthetextureontheoceanplane.There'snothingwrongwiththetexture,butweneedtoscaleuptheUVmappingslightlytoincreasethedetailonthewatersurface.

Noticehowevenslightchangescanimprovetheoverallappearancedrastically.Ialsotweakedthesea'svertexcolorsslightlytomorecloselymatchthesky.

Nowlet'saddsomesubtlewavesthatlapattheedgesoftheisland.Addaplaneattheedgeoftheislandandbeginextrudingitsoitfollowstheedgeclosely.Keepdoingthisuntilyou'vecircumnavigatedtheisland,thenmergetheendstogethertocreateacontinuousring.

Makeaniceblack-andwhiteripplestexture,andmapit1/1tothefaces.SetallthefacestoAddrendermode,andpainttheouterverticesblack.

Thesesmallripplesintegratetheislandwiththesea,finallypullingtogethereveryaspectofourgamescene.Ifyou'dlike,youcanevenanimate

t

hemwiththeUVscrollPythonscript.

Foronefinaltouch,youmaywishtocreateshadowsforyourpalmtrees.Anicetutorialabout

creatingshadowtexturesforgameswascreatedbymastergamemakerST150,andisavailableat

http://www.blending-online.co.uk/8501/50779.html

ClosingMaybeyoudidn'twanttocreateasimpleislandlikethisone,andmaybeyoudidn'teventrytofollowalong.Itdoesn'tmatter:myhopeisthat

whilereadingthisarticle,yougainedabetterunderstandingofhowtothinklikeagamedeveloper.Whetherornotyounowhavealittleislandscenedoesnotmatter,whatmattersisthatnowyoubetterunderstandtheconceptsandapplicationofgamescenecreationinBlender.

Planaheadtocreatethebestscenepossible.Trytostartwithsomeideaofwhatyouwantthefinishedprojecttolooklike.Createconceptsketchesifyouprefer.Shadeyourmodels,eitherthroughvertexcolorsorbyusinglightsimulation.Keepyoureyesopenintherealworld,andtrytolearnhowlightbehaves.

Thinkwhileyoumodel:neveruse10facesifthreewilldo,anduseface-dividingtoolssparingly.Deleteunneededfaces,andnevermakeyour

modelsmorecomplicatedthannecessary.Trytoseehowsmallafacecountyoucanget.

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Image54CompletedIsland

Image52MakingWaves

Image51ImprovedOcean

Image53MakingWaves

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Createyourowntextureswheneverpossible.Bringyourcamerawithyouontrips,andphotographas

manydifferentsurfacesaspossible.Whenprocessingyourtextures,strivetoobscuretherepetition.Neverbeafraidtoaddrealisticdetails,especiallyoneswhichhavelittleeffectonpolycount.Asafinaltouch,youmaywanttoexperimentwithaddingmotion.Aslightswayingtothetreesoraspinningweather-vanecanaddtothegame'slookbeautifully.Theworldisfullofmotion,andalittlemotioncanbeagreatadditiontoyourgame.Trytomakesurethattheplayerisnottheonlythingmovinginyourworld.

Andthat'sthat!Ihopeyouenjoyedreadingthe

article.I'vestrivedtoincludeinthisarticleeverythingabeginninggameartistmightfinduseful.Admittedly,therearealotofthingsIdidn'tmention,butthereisenoughmaterialheretogetsomeoneontheirfeetandsolvesomecommonproblems.Withtheseskillsinplace,youllbewellonyourwaytocreatingagreatBlendergame.GostartupBlender,andgettowork!Ilookforwardtoseeingwhatyoucreate!

23



IhavebeenusingBlendersinceApril2000.Mycurrentgameprojectisanadventuregamecalled"IntotheTitan."

Website:

www.gorilla3d.com/plantperson

JohnAllie/PlantPerson

Image51ImprovedOcean

24

3D Workshop
http://www.gorilla3d.com/plantpersonhttp://www.blenderart.org/


24/46

Introduction

VectorBlurisaninterestingsolutionthatgoesbeyondthelimitationsofregularMotionBlur.ItreliesontheCompositeNodesEditortoperform.ButeveniftheNodesEditormaylookintimidatingatfirstglance,itisinfactveryeasytosetup.Thisshorttutorialwillgothroughthebasicstepsforenhancingyourrenders(bothstillsandanimations)withgoodlookingmotionblur.

Themainthingtounderstandisthattheobject,towhichtheMotionBlurwillbeapplied,shouldhavebeenanimatedbeforehand.ThismeansthattheobjectmustfollowacurveorbeanimatedusingIPOs.Infact,therenderedpicturewillbeturnedintoa3Dmodelwithdepth,andaspeedvector

willbecalculatedforeachpixelofthepicture.Asapost-process,theCompositeEditorwilladdthemotionstothefinalpicinablurredway.Thisiswhydefiningthemotionoftheobjectisabsolutelymandatory.

AverybriefexamplefileofsuchananimationcanbefoundatthefollowingURL:http://feeblemind.tuxfamily.org/dotclear/images/atelier-improbable/vector

Astep-by-stepoftheVectorBlurprocess

First,youwillneedtoturnoneofyour3DviewsintoaNodeEditorview.Thisisdonebyclickingonthegrid-likeiconattheleftendoftheHeaderoftheview.Amenuwillpopupandletyoudefinethetypeofviewneeded.ChoosetheNodeEditor.

IntheHeaderoftheNodeEditor,youwillfindamenufortheview(View,Select,Add,Node)andthentwoicons:(thegreysphereicon)enablesMaterialNodes,and(thesmallfacepictureicon)enablesCompositeNodes.ClicktheCompositeNodes..ThedefaultCompositenodesnetworkshouldbedisplayedonthescreen.Usingthe[LMB],drawaboxthatwillcrossthelinkbetweentheRenderLayernodeandtheCompositenode:thelinkshoulddisappear.Now,usetheAddmenu:Add>>Filters

>>VectorBlur.Anewnodeshouldappear,titledVectorBlur.Moveitbetweenthetwopreviousdefaultnodes,andstartthemagic:connectthe

outputImage,ZandSpeedfromtheRenderLayernodetotheinputImage,ZandSpeedfromtheVectorBlurnode,usingthe[LMB].Oncedone,connecttheoutputImagefromtheVectorBlurnodetotheImageinputoftheCompositenode.

24


3DWorkshop-BlenderAndVectorBlur

BlenderAndVectorBlur

-by Olivier Saraja

Image1AnexampleofIPOcurvesaffectingamovingobject.

Image3TurnoneoftheviewsintotheNodeEditor

Image2Here'showitwouldlookonaregularanimationrendering,withoutvector-basedmotion

blur

Image4ClickontheCompositemodeiconandthenactivatetheUseNodesbutton.

253D Workshop l d d l
http://feeblemind.tuxfamily.org/dotclear/images/atelier-improbable/vector-blur/vectorblur_example.blendhttp://www.blenderart.org/


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But,likeanythingelseinBlender,takingintoaccounttheeffectoftheVectorBlurisnothingbutanoption.YouneedtotellBlenderthatitmustdothepost-processingsimulatingthemotionblurexplicitly.ThisisdoneintheScene[F10]menu,intheRenderbuttons,intheAnimpanel.YouwillhavetoactivatetheDoCompositebutton.Asafinalpre-requisiteforVectorBlurmotions,youwillneedtoactivatetheVecoptionintheRender

Layerstab.

Youcannowrenderyourpictureintwoways:

Youobviouslyalreadyknowthe[F12]shortcutortheRENDERbuttonintheRenderpanel

YoucanalsorenderthepictureusingthetinyRendericonintheRenderLayernode

SomeexplanationsontheVectorBlurnodeThisnodeonlyhasafewsettings;mostofthemcouldworkquitewellwiththeirdefaultvalues.Butsometimes(ifnoteverytime!),youneedtogobeyonddefaultsettingstogetrealcoolresults.

Therearefoursettingstoknowabout.

Samples-Thissettingcontrolstheblureffectintensity:thehigherthesamples,themoreblurredtheobjectwilllook.MinSpeed-Ifeverythingisblurred,butsomeobjectsarealotslowerthanothers(ortotallystatic,asthebackgroundofthepic,forexample),thenthisparameterwillhelpdifferentiatehigh-velocityobjectsfromnull-velocity(orslow-

velocity)objects.Thisisreallyusefulduringcameramovementsorslightbackgroundmovements.MaxSpeed-Ifyouhaveextremelyfastobjectsinthescenebuttheblurdoesnotrenderwellenough,thenyoucanmakeuseofthisparametertobetterthevectorblur.Notethata0.0valuemeansthatnomaximumisused.BlurFac-Thisparameterwillscalethevectorspeeds,calculatingfromthemovementsoftheobject.Thevisualeffectisclosetotheshutterspeedofaregularcamera.

ConcerningtheuseofVectorBlur,agoodtipistoputfastmovingobjectsonaRenderLayer,sloworstaticobjectsonanother,andtospecifyindependentparametersforeach,forbettercontrol.

Moreover,largeobjectsnotentirelyseenfromthecamerashouldbesubdividedsothatatleast

somenormalsoftheobjectareactuallyseenfromthecamera,ortheblureffectcouldbedrawnonthewrongside,comparedtothemovement.

Therearesomelimitationsthatyoushouldknowabout.

25


3DWorkshop-BlenderAndVectorBlur

Image2Here'showwouldlookthesameanimationrendering,withvectorbasedmotion

blurenabled

Image4TheCompositenodesaresettodeliveraVectorBlurbasedrendering

Image5Donotforgettoactivatethe

DoComposite

buttonintheAnimpanelandtheVecbuttoninthe

RenderLayerstab

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SinceVectorBlurisapost-processeffect:

ifanobjectisvectorblurred,itsshadowisnotblurred!

ifavectorblurredobjectismovingbehinda(ZTransporRayTransp)glass,itwon'tappearblurredthroughtheglass

ifavectorblurredobjectismovinginfrontofa(EnvMaporRayMir)mirror,itwon'tappearblurredinthereflection

26


3DWorkshop-BLenderAndVectorBlur

OlivierSarajaisanOpenSourceenthusiastrunning

onLinuxsince1999orso.HeusesBlendersince

version1.63aandalwaysdedicatedhimselftowriting

tutorialsforthecommunity,bothinfrenchandin

english.Hehasjustwrittenafrenchbookabout

Blender:"La3DLibreavecBlender"(whichcouldbe

translatedas"Free3DwithBlender")at

EyrollesEditions:

http://www.editionseyrolles.com/Livre/9782212119596/la-3d-libre-avec-blender

HeisalsoacasualWikicontributorofBlender's

documentation.

OlivierSaraja

273D Workshop B & Di l t M i f B i
http://www.editions-eyrolles.com/Livre/9782212119596/la-3d-libre-avec-blenderhttp://www.blenderart.org/


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Introduction

BumpmappingandDisplacementmappingaretwospecialtechniquesformakinganobjectappeartohavearoughorirregularsurface.

WhatisBumpmapping?Bumpmappingtakesagrayscaleimageandreadsthelightanddarkinformationtosimulateanirregularsurface.Whenyourenderanobjectwithabump-mappedmaterial,lighter(whiter)areasofthemapappeartoberaisedanddarker(blacker)areasappeartobelowered.Notethatbump

mappingdoesnotmodifythegeometry,onlythenormals.

Thebumpsareasimulationcreatedbyperturbingfacenormalsbeforetheobjectisrendered.Therefore,bumpsdon'tappearonthesilhouetteofbump-mappedobjects.Bumpmappingisusefulforaddingdetailtoanobjectwithoutincreasingthepolygoncount.

WhatisDisplacementmapping?Displacementmappingisverysimilartobumpmapping;whereatwo-dimensionalimage'sgrayscaleinformationisusedtochangethe

appearanceofathree-dimensionalobject.Lightertonescreateraisedbumpsanddarkertonescreateloweredindentationsasusual.Unlikebumpmapping,whichonlyaffectstheobject'stexture,displacementmappingaffectstheobject'sgeometry,creatingadditionalpolygonsaccordingthedisplacementmap'sproperties.

Displacementmappingcanbeverydemandingonyourcomputer'sperformanceasittendstocreate

anextremelylargeamountofpolygons.Thishighresolutionobjectcanappearmuchmorephoto-realisticthanbumpmapping,ifusedproperly.Ascomputersarebecomingmoreandmorepowerful,displacementmappingmaysoonbeabletorenderatspeedsnecessaryforareasonablegameengine.However,currenttechnologydoesnotmeettheheavyprocessingrequirement.

BeforeyoustartBumpmapping&DisplacementmappingtechniquesareveryfastandeasytodoinBlender,evenifyouarenewtoBlender'stexturingtools.Pleasenotethatdisplacementmapsarenotdisplayedin

the3Dviewport.Bumpmapscandisplayaverybasicpreviewwithshading[Shift+Z]turnedon.

BumpmappinginBlenderForthistutorial,IwilluseoneofBlender'smanyproceduraltextures,"Musgrave".Feelfreetopickanothertype,or

evenuseyourownbumpmapimage!BeginbyopeningBlenderandcreatinganewobject.Iusedthepopular"Suzanne"(monkey)modelforthisexample.Next,createanew

materialintheMaterialShadingPanel[F5],andaddanewtexture.NowswitchtotheTexturingPanel[F6],wherewewillcreatethebumpmap.Fromthe"TextureType"box,select"Musgrave".Ileftthedefaultsettingsalone,butyoumaychoosetoplayaroundwiththem.Youcanalsoaddaramp-shaderhereifyouareplanningonaddinguniquecolorstothetexture.

Now,weneedtoconfigurethemostimportantsettingsforthebumpmap.ThesecontrolsarelocatedintheMaterialShadingPanel[F5]underthe"MapTo"tab.Youmaychoosetodisablethetexture'scolor(Col)whenmodifyingyourbumpordisplacementmaps.Thiscansometimesgiveyouabetterideaofwhat'sgoingonwitheachsetting.

Toenablebumpmapping,pressthenormal(Nor)button.Youcanadjustthestrengthofbumpinesswiththesliderbuttonlabeled"Nor".Usebumpmapswhenyouwanttotakethesmoothnessoffasurface,ortocreateanembossedlook.Keepinmind,however,thatthedeptheffectofabumpmapislimitedtothenormal(Nor)slider.

27


3DWorkshop-Bump&DisplacementMappingforBeginners

Blender&DisplacementMappingforBeginners

-by Michael Wach

Image4EnablingNorMapping

Image1RegularTexture

Image2BumpMap

Image3DisplacementMap

283D Workshop B & Di l t M i f B i


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DisplacementmappinginBlenderThewayyoucreateadisplacementmapisverysimilartothewayyoucreateabumpmap.Theonlydifferenceis,youmustenablethedisplacement(Disp)button.Youmayturnoffthenormal(Nor)buttondependingonyourdesiredeffect.

Thedisplacementslidercontrolshowfarawayfromtheoriginalmeshtheverticeswillbemoved.Thenormal(Nor)slideralsohasagreatimpactonyourdisplacementresults.Becarefulwhenusingdisplacementmapsbecausetheycanbeveryprocessordemanding.

Conclusion

Overall,bumpmappinganddisplacementmappingareveryhandytoolsifyouknowhowtousethem.Mapsthatshadebetweenwhiteandblackgenerallyworkbetterthanmapswithhardedgesbetweenthewhiteandblackareas.Ihighlyrecommendplayingaroundwiththesettingsandrenderingyourresultstohelpdeepenyourunderstandingofthemboth.

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3DWorkshop-Bump&DisplacementMappingforBeginners

Image4EnablingDisplacementMapping Isan18yearsoldfromCleveland,Ohio.CurrentlystudyingattheUniversityofAdvancingTechnology.HeworksoverinternetforaNewYorkCitybased

patentattorney,creating3DrepresentationsofhisideasusingBlender3DandYafRay.Alsomakewebsites,composedigitalaudio,recordandeditdigitalvideosandworkswithalotof2Dillustrations,textures,andphotographs.

[email protected]

MichaelWach

292D Workshop C ti A Li ht i B lt i th GIMP
http://www.mikewach.com/http://www.blenderart.org/


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IntroductionThistime,wewilllearntheprocedureforcreatingalightningboltspritefromtheGIMP.Lightningboltsfindgoodusein3DgameSFX,likezappinganitemorenemyfromanelectricweapon,denotingtensioninsci-fiscenarios,orjustanaturallightningbolttoenhancetheenvironmentalmood.

Level:NewbietoIntermediate

Step1.LaunchtheGIMPandcreateanew256x768image.GotoFilters>>Render>>SolidNoise.Inthepop-up,enterthevaluesasshowninImg1or,chooseoneofyourownbyhitting'New

Seed'button.Finally,presstheOKbuttontorenderthenoise.

Step2.Createanewlayeroverthecurrentlayer.GototheToolBoxandselectthegradienttoolandintheToolOptions,selecttheshapeofthegradientasBi-linearandenableAdaptive-

Supersampling.Createanewlayeroverthenoiselayeranddrawasmallgradientoverthenewlayer(seeImg3)).Onethingtorememberhereisthatyoushouldtrytodrawthegradientoverthepartofthesolidnoisewhichcontainsmostlywhiteanditssurroundingareasaredarker.Thatiswhereyougetgoodcontrastforthelightbolt.

Step3.GototheLayersdialogboxandchangethelayer-modeofthegradientlayertoDifferenceseeimg4.Immediately,youcanseetheformationofthebolt.Nowgo

toImage>>FlattenImagetoflattenallthelayersintoonesinglelayer.NowgotoLayer>>Color>>Inverttoinvertthecolorofthelayer.

Step4.Whatyougetisastreakoftwolightningbolts(Seeimg5),butthese

boltsarehardlyusableastheyappearvirtuallygluedtogether.GotoLayer>>Color>>Levels.ThiswillbringuptheLeveladjustdialogbox(seeimg6).Dragtheinputlevelsmid-pointertowardstheright.

Whileyoudothis,youcanalsoseetheformationoftwoneatlightningbolts(Seeimg7).Adjusttheamountofsharpnessyouwantthen,pressOK.

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2DWorkshop-CreatingALightningBoltintheGIMP

CreatingALightningBoltintheGIMP

-blenderart

Image1SolidNoisepop-up

Image2Gradientsettings

Image3DrawnGradient

Image4LayersDialog

Image5Lightningbolts

Image6Leveladjustment

302D Workshop Creating A Lightning Bolt in the GIMP


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Step5.ToseparatethelightningboltsasanAlphachannel,youwillneedtoconverttheblackcolortoalpha.Todothat,gotoLayers>>Transparency>>ColortoAlpha.IntheColortoAlphadialog,clicktheFrombuttonandchooseablackcolorthenpressOK.Younowhaveanalpha-basedversionofthelightningbolt(Seeimg8).Thelastthingtodoissaveitinafileformatthatsupportstransparency,likePNGorTGA.

ConclusionAlthoughthismethodonlygeneratesprettystraightlightningbolts,youcancomplimentitwiththenoisegenerationplug-insfortheGIMPcalledPlasma2etc.Thiswillallowyoutohave

randomnoisegenerationwhichcanresultinmorevariedlightningbolts.Ihopethishasprovidedyouwithaniceandeasywaytocreatelightningbolts.

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2DWorkshop-CreatingALightningBoltintheGIMP

Image7Renderedlightningbolts

Image8Lightningboltswithalphachannel

31Blending - A Compositor Node Overview


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SandraGilbertandIdiscussedthefactthatwithallofthenewfeaturescomingfromtheBlenderreleases,itisoftenhardtokeepupwiththem.Often,youneveractuallygettousethefeatureinaprojectbecauseyouaresimplytoobusyexploringallofthedifferentwaysofusingthenewfunctionality.Tohelpthosegetuptospeedfaster,I'llgiveaquickoverviewoftheCompositorNodesystem.

CompositorNodeSystemTheCompositorNodeSystemisanadvancedpost-productioneditorthatallowsforquickandeasyconfigurablemodifiers,callednodes,tobe

hookedtogether(usingnoodles)basedonvariousinputsandoutputs.Theconfigurationsareflexibleandtheresultscanbequitedramaticorverysubtlebasedondesignandnecessity.ThemajorfeatureoftheCompositorNodeSystem(Compositor)istheabilitytomixvariousrenderpasses(combinedRGBA,Z,Vector,andNormalvalues)withotherinputstoachieveadvancedeffects.ThesefeatureshavecomeaboutmainlythroughthedevelopmentsmadebyOrangeStudio

andjustrecentlybytheprojectPlumiferos.Althoughdesignedforanimationsandcomputer-generatedimagery,theCompositorhasfounditswayintothetoolboxofmanygraphicartistswhouse3Dand2Dprogramstocreateillustrationsandartwork.Thepossibilitiesareonlylimitedbyyourimaginationandabstractionofthenode-basedlayout!

InputsValues

InputsarevariablesettingsonallEffectandOutputnodes.Inputnodesdonotcontaininputsthemselves,theyusetheinputsfromtheactualScene.AninputcaneitherbeanRGBAvalue(Imageinputs)orarangevalue(Factor,Size,Valueinputs).ThekeydifferencebetweenRGBAvaluesandrangevaluesarethateachpixelrepresentsacolor/alphavalueoravaluerepresentinganinputamount(0-255).RGBAvaluesaretypicallythepixelsthatmakeupthefinalimagewhereasrange

valuesaretypicallyvaluesthatcontrolthetransformingofthepixelsandareusuallyZ,Vector,Normal,Alphaorotherrangevalues.

Inputscanonlyacceptoneinputchannelandrepresenttheentirepictureonaperpixelbasis.Inputsareeitherfromthesceneortakenfromtheoutputofanothernodeorasetvalue(suchasImageinputs,whichcansimplyuseanRGBAvalue).

AnRGBAvalueinputisalwaysyellowandarangevalueinputisalwaysgray.Blueinputsarespecialinputswhichonlyworkwiththeassociatedscene

data(NormalandVectorchannels).AnRGBAvalueinputmayhavetobeconvertedtobeusedasarangevalueinput.Aninputthatrepresentseachpixelinanimageisoftenreferredtoasanpixelorimagemap.

OutputValuesOutputsvaluesarevariablesettingsonallEffectandInputnodes.Outputnodesdonotcontainoutputsthemselves,theydisplaytheinputs.Just

likeInputValues,OutputValuesareeitherRGBAorrangevalues.AnRGBAvalueoutputisalwaysyellowandarangevalueoutputisalwaysgreyandspecialchannelvalues(NormalandVectorchannels)arealwaysblue.Toviewrangevalues,youmayhavetoconvertittoanRGBAvalueorusespecialfilterswhenviewing.Anoutputthatrepresentseachpixelinanimageisoftenreferredtoasapixelmaporimagemap.

Withthatquickprimeroninputsandoutputsandwhatcanandcannotbeused,letustakealookathowtheseinputsandoutputscanbeusedtogetherwithnodes.Pleasenotethatinthefollowingexplanations,anactualworkingmodelwon'tbedescribedbutratherhoweachsettingcanbeusedwithineachnodeandhow,whencombinedwithotherinputs,theywillchange.

InputNodes

RenderLayerNodesareinputsfromtheScene.CurrentlytheonlyavailableoutputsettingsforthisnodeincludeImage(RGB),Alpha,Z(depth),Normal(mapping),andSpeed(vector).TheRenderLayerNodecontainsanImagePreviewandaselectorforselectingScenesandRenderLayersfromtheselectedScene.NotethattheNormalandSpeedvalueoutputsarecoloredblue,thisisbecausetheyarespecialvalueoutputs.Theycanbetreatedthesameasanyrangevalue,butonlyworkforrelatednodes.

TheImageoutputdisplaystheRGBcolorvaluesforeachpixel.TheAlphaoutputisablackand

whiterangevaluewhichrepresentstheopacityforeachpixelwitharangefrom0(black/transparent)to255(white/solid).TheZoutputisarangevaluethatgivesdepthinformation(thedistancefromthecameratothevirtualobject)onaper-pixelbasis.

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Blending-ACompositorNodeOverview

ACompositorNodeOverview

-by Daniel LaBarge

NOTE:Thedescriptionofhoweachnodeworksisbasedonlyontheutilityandnotontheactualmathematicalorgraphicalfunctionalityofthenode.AmoreaccuratedescriptionofhoweachnodefunctionsandoperatesisbeyondthescopeofthisarticleandwillprobablyappearinfuturearticlesontheBlenderWikiathttp://mediawiki.blender.org.

http://mediawiki.blender.org/http://www.blenderart.org/


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ImageNodesareinputsfromanimagefile.Animagefilecaneitherbeavalidimagetypefile(jpg,png,bmp,etc.)orarangeimagetypefile(exr,hdri,etc.)orevenamovingimagefile(avi,mpeg,mov,etc.).CurrentlytheonlyavailableoutputsettingsforthisnodeincludeImage(RGB),Alpha,andZ(depth).ThisnodealsocontainsanImagepreview.

Whenafileisloaded,asmalliconrepresentedbyfilmtapeappears.Whenyouenablethis,moreoptionsbecomeavailable.Youcansetthenumberofframesintheanimationandsetthestartingframeandwhetherornottocyclethroughtheframes.Thismakesusingrawimageoutputfromtheanimationrendereasytoloadintothecompositorforpostproduction,sinceBlendernameseachframebasedonanumber.

Also,Blendercanreadthefilenameandgetthenextframeoftheanimation.Anothericonalso

showsupandcanbeenabled,whichwilltakeeachframefromthefileifthefileisamovingimage.Typically,onlytheImage(RGB)outputisusedbut,ifascenefileiscreated,youcanuseitasinputwhichwoulddelivertheAlphaandZvaluestobeused.

ValueNodeisaverysimplenode.Yousetanumericvalue(0.00to1.00)andthevalueoutputdeliversitasarange.Programmerscanthinkofthisaspredefinedvariable.

RGBNodeisbasicallythesamethingasaValueNodeexceptthatitoutputsanRGBAvalueinstead

ofarangevalue.Thisnodecontainsacolorpalettewhichmakesiteasytoselectthedesiredcolor.

TimeNodeisaverypracticalnodebecauseitisessentiallyavariableValueNode.Thedifferenceisthatthevariationisbasedonthenumberofframes.TheFactoroutputisarangevaluewhichissetusingacurve.YoucansettheStartandEndframeforwhichthecurverepresents.Thisnodeis

usefulforcontrollingthechangesthatoccurduringananimation,andisoftenusedasaninputforanothernode.

TextureNodeissimilartotheImageNodeexceptthatitusesinternaltexturesfromtheBlendersceneastheinputs.ThisgivesyoualotofcontrolbecauseyoucanuseNormalmappingtocontroltheOffsetandScalingdynamicallyandcanusetheRGBAvaluesaseitherarangeValueoutputoranRGBAColoroutput.ThisnodealsoincludesanImagepreviewwhichdisplaysthetextureselectedfromthescene.Thisisgoodforaddingproceduraltextureoverlaysandgradienteffects.

OfalloftheInputNodes,onlytheTextureInputactuallyhasinputsettings.ThesearelimitedtotheBlenderscenehowever,theyarestilldynamic.Overall,theInputNodesareessentialtousingtheCompositorastheyserveasthebasetowhichchangesaremade.Theyalsoallowforcontrol

overeffectsappliedtootherinputs.ThethreemostcommonlyusedInputNodesaretheRenderLayer,Image,andTimenodes.

OutputNodes

CompositorNodesoundskindofredundantbut,itisactuallytheonlywaytooutputthefinalchangestotheRenderBuffer.Currently,therecanonlybeoneCompositorpersceneanditonlyacceptsImage,Alpha,andZinputs.ThenodeusesanImagepreviewfordisplayingtheresultsintheNodeWindow.TheRenderBuffer(F11)willalsodisplaytheCompositornodeoutput.IfnoCompositornodeisfoundtherendererwill

produceanerror.

ViewerNodeisidenticaltotheCompositornodeexceptthatinsteadofdisplayingresultstotheRenderBuffer,itutilizestheUVImageEditorundertheViewerImage.ThisisadynamicimagethatdisplaysthepreviewofthecurrentlyselectedViewernode.ThismeansthatyoucanhavemultipleViewernodeswhichwilldisplaythevariousoutputsofothernodes...usefulfordebuggingandtestingdifferentattributesofthecomposition.

ColorNodes

RGBCurvesNodeisaverypowerfulnodebecauseitcancontrolthecoloroftheimagebyvaryingtheinfluenceofeachcolorseparately,andallofthecolorstogether.ThisnodehasaFactorInput(rangevalue)andanImageInput(RGBAvalue).TheImageOutputisacombinationofallof

theRGBCurveswhichincludeCombined,Red,Green,andBlue.Thereare+and-symbolswhichzoominandoutaccordinglysothatyoucanfinetunethecurveandalignitmoreeasilytothegrid.

Thewrenchiconallowsforcontroloverthegridviewandthecurvehandling(AutoandVector),anditalsoallowsyoutoresetthecurvetothelineardefault.Anorangegridiconallowsforclippingtocontrolthemaximumvalues.TheXicondeletesthecurrentlyselectedpoint.PointsareselectedusingtheLeftMouseButton(LMB).

NewpointsareaddingbyusingCtrl+LMB.Thisnodeismostcommonlyusedforcontrastcontrolandforfinetuningthecolorranges.Itiseasytomakeveryboringimagesinterestingusingthisnode.

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NOTE:Atthetimeofthiswriting,CVSversionsofBlenderincludenewoutputnodes.ThesenodeswillnotbediscussedinthisarticleastheyhavenotyetmadeitintotheofficialBlenderrelease.Youshouldnote,however,thatadvancednodesdoexistandwillprobablybemakingtheirwayintofutureBlenderversions.



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MixNodedoesexactlywhatitsoundslikeitmixestwoImageinputsbasedonaFactorandfiltertypeandoutputstheresultasanRGBAvalue.ThisnodehastwoImageinputs,butitwillacceptrangevalues.ThismakesitgoodformixingapresetvaluewithaTimeNodevaluetohaveavaryingrangevaluefornodesthatdon'thavemultiplerangeinputs.Amongthefiltertypesaremix,multiply,add,subtract,divide,screen,overlay,darkenonly,lightenonly,andmanyothers.ThisnodeisgoodformixingcolorsaswellbecausetheImageinputscanbesetasafixedRGBAvalueinsteadofapixelmap.

HueSaturationNodeisperfectforfinetuningtheRGBcolors.Ifblueisn'tblueenough,thisisthenodethatyouwillfindthemostuseful.ItacceptsanImageinputandaFactorrangevalueinput,andoutputsthemodifiedImage.TheHueslidercontrolstheHuevalues(similartoRGB)with0.500beingnochange.TheSaturation(intensity)slider

controlsthesaturationoftheHueswhichcanbeusedtofloodaphotoorjustslightlytintanimage.Thisnodeisveryusefulandismostpopularlyusedasatintfilterforsuchnightsceneswhereaslightbluetintisneeded.

AlphaOverNodeisthetitleeffectlifesaver.Thisnodeallowsoneimagetobelaidoveranotherandtransparencyisusedasthewindowinwhichthebackgroundisletthrough.ThisnodehastwoImageinputsandaFactorrangevalueinput.TheFactorcanbeeasilyconnectedtoaTimeNodeandthenyoucanfadein/outtheeffect.ConvertPremulusuallyblendsthetransparentedges

togetherbettersoartifactsareremoved.ItalsoconvertsRGBblacktoAlpha,whichworkswellforcreatingAlphamaps.

It'simportanttokeepalayermentalitywhenworkingwiththisnode.ThetopImageinputisthelayerwhichisplacedontopofthebottomImageinputandtakesprecedenceoverthepixel.Anytransparentpixelsthenallowthebackgroundtoshowthrough.Thisnodeisgreatforoverlaysand

titleworkaswellascompositingscenes.

ZCombineNodeisaveryinterestingnodeinthatitcaneasilygettangled.IthasasingleImageoutputbutacceptstwoImageinputsandtwoZrangevalueinputs.ItcombinesthepixelsbasedontheZrangevaluesandpassesthatcombinedimagetotheoutput.TheproblemwiththisisthattheZvaluethatcorrespondstotheImage(atleastinthescenariowherethisnodeisuseful)isthebelowtheoppositeImageinput.

Thus,thenoodlesthatconnectthenodescaneasilygetcrossedandfollowingthemgetsmessyifmultiplenodesareused.Thisnodeismostcommonlyusedwithscenecompositing.Inthismethod,thesceneisrenderedinsectionsandlayers.Thelayersarereassembledafterpost-productioniscompleted.Usuallythescene'sZchannelisusedtodothis.

VectorNodes

NormalNodehastobeoneofthecoolestnodesavailable.Ionlyrecentlyfiguredouthowamazingitreallyis.Basically,youcanthinkofitasapost-productionlight.ItusestheNormalchannelasitsinputandthenyoucanmovealittlespherearoundtorelocatethelightsource.TheavailableoutputsincludetheremappedNormalchannelandaDotrangevalueoutputwhichrepresentsthelightandnormalintensityinagrayscalepixelmap.Thepossibilitiesforthisincludespecularmapping,nightlighting,subsurfacescattering,andmuchmore.

VectorCurvesNodeissimilartotheRGBCurvesnodeinthatyoucancontroltheVectorchannelvaluesfortheX,Y,andZaxis.TheonlyinputandoutputareVectorchanneldatawhichmustbeloadedeitherfromaNormalnodeorthesceneitself.Itcontainsthestandardcurvewidgetandcontrolfeatures.ThisnodeismostusefulforremappingtheVectorchannelforfinetuningmotionblur,etc.

MapValueNodeisanotherusefultoolforchangingvalueranges.ItacceptsanyrangeValueinputandcanlimititsMinimumandMaximumvaluesandcanbefurthermodifiedbasedonSizeandOffsetvalues.Theseslidersarenotlimitedto0.0and1.0becausethisnodeisnotdesignedonlyforrangevaluesofthatkind.ItalsoacceptsZ,Normal,andVectorchannelsandcanisoftenusedincombinationwiththeZchanneltoremapitforforegroundandbackgroundblurorincombinationwithaVectorchanneltoproducemotionblur.

FilterNodes

FilterNodeisthemostcommonlyusednodeinthisset.Itcanbeusedforabroadrangeofeffects,suchassoftblurring,edgeenhancementsforcartoons,neonsigns,decals,andmuchmore.ThisnodeacceptsanImageinputwhichcanbecontrolledusingaFactorrangevalueandwillthenmodifythepixelsbasedonadifferentfilteror

effecttype.TheresultispassedtotheImageoutput.Thesoftenfiltertypeappliesaverysmallblurtothepixeltoeliminatesmallartifacts.Sharpenattemptstoenhancetheedgesbetweenthepixelstodefinetheedgesbetter(thisoftencreatesartifacts).Laplace,Sobel,Prewitt,andKirschareallverysimilarandtheyenhancetheedgesanddarkentherest.Shadowiskindoflikeengravingandappliesaselfshadowontheedges.Thisnodeisoftenusedtomakeimagesthataretooperfectseemcrisper.

BlurNodeisaverysimplenode.IttakesanImageinputand(basedonaSizerangevaluewhich

influencestheamountofblur)willblurthepixelsbasedondifferentfiltersormethods.ItwillfilteritbasedonanXandYvalueandcanevenbeappliedtoGammacorrectedvalues.EnablingBokehfilteringwilluseacircularfilterinsteadofthesimplesquaremethod.AmongthefiltermethodsavailableareFlat,Quadratic,Cubic,Gaussian,CatRom,Mitch,andTent.





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Eachonefiltersdifferentlyandanyoneofthemcanbeusedtoobtainthedesiredeffect.TheresultingeffectisappliedtotheimageandpassedtotheImageoutput.ThisisveryusefulforDepthofFieldandmotionblur.Itcanalsobeusedcleverlyforinterestingtitleworkandoverlays.

VectorBlurNode isbasicallyaone-purposenode,butitdoesitsjobverywell.Itrequiresthreeinputstogeneratethedesiredoutput.ThesethreeinputsareanImage,aZchannelmap,andaVectorSpeedinput.AllofthesecanbegatheredfromthesceneandVectorNodes.Thismethodusesallthreechannelstogethertoblurtheimagebasedapixelstretchingmodel.Theinnerworkingsofthismethodarebeyondthescopeofthisarticlebutthefunctionalityisaveryfastandefficientpost-productioneffect.ItusesaSamplevaluetocontrolthequalityoftheblur,aMinSpeedtosettheminimumstretchforeverypixelandaMaxSpeedforthemaximumstretchforanypixel.It

thenusesaBlurFactorwhichcanbeusedtofine-tunetheblurfromstrongtoweak.ThehighertheSamplesandthehighertheBlurFactor,thestrongertheblur.ItisimportanttosettheMinandMaxspeedstoinclusiveenoughvalues,butnottoobroadtobecomememoryintensive.Thisnodeismostoftenusedformotionblur.

ConverterNodes

ColorRampNodeisadualpurposenodeinthatitblendscolorsandvalues,andoutputsbothanRGBImageoutputandarangevalueAlphaoutput.Thealphaoutputcanbeusedasanyvalueoutputbut

ismostoftenusedfortransparency.TheFactorinputcanbeeitherarangevalueoratimelinecontroltocontroltheinfluenceofthenode.Therampslidercanusecolorsandtransparenciestocreateagradientwhichisusefulforgradienteffectsonoverlaysandforvaluetuning.

RGBtoBWNode isthesimplestnodeavailable.IttakesanRGBAImageinputandoutputsarangeValueoutput.Thisisagrayscalerepresentationof

theRGBAImageinputandcanbeusedassuchorasavalueoutput.

SeparateRGBANodeisveryversatilebecauseitallowsyoutomodifyeachcolorchannelindependently.ItacceptsanRGBAImageinputandoutputsthecorrespondingRed,Green,Blue,andAlphachannelsasgrayscalevalues.Atthetimeofthiswriting,thenextofficialreleaseofBlenderwillincludeaCombineRGBANodewhichwilldothereverseofthisnode.

SeparateHSVANodeisessentiallythesameastheSeparateRGBAnodebutitseparatestheHue,Saturation,Value,andAlphachannelsfortheimage.TheyaregrayscalevaluesjustliketheSeparateRGBAnode.Atthetimeofthiswriting,thenextofficialreleaseofBlenderwillincludeaCombineHSVANodewhichwilldothereverseofthisnode.

SetAlphaNodeisgoodfortitleworkandoverlaysbuthasit'spurposeinothernodesaswell.ItacceptsanRGBAImageandthenallowsanAlphavaluetobesetoroverwrittenbyaValueinput.Alphavalueof0.0istransparentand1.0isopaque.ThecombinedRGBAvaluesarepassedtotheImageoutput.ThisnodeisoftenusedwithaTimenodetocontrolthefadeinorfadeoutofascene.

TranslateNode istheonlymovinganimationnodeavailableatthemoment(moreadvancednodesforrotation,etc.arebeingdeveloped).ThisnodewilltranslateormoveanImageinputasetvalue

fromthetopleftofthebasecanvassize.ItwillbemovedX(horizontal)pixelsbyY(vertical)pixels.ThesevaluescanbevariableXandYinputswhichisusefulforanimationswhereaTimenodecanbeusedtoslideasceneorimageacrossthecanvas.TheresultingImageisoutputwhichcanthenbeplacedontopofanotherImageformergingdown.

GroupNodes

GroupnodesarenothingmorethancustomnodeswhicharemadebytakingthegenericnodesandgroupingthemwithCtrl+Gkey.Thisgroupisthenavailableasaduplicatetothecurrentgroup.Toungroupthenodes,youcanpressAlt+Gkey.ToaddagroupnodeyoucaneitherusetheAddmenuorpressShift+Gkeyforalistofcurrentlyavailablenodes.Workingwithgroupnodescansavealotoftimeforrepetitiveeffects,butshouldbeusedwithcaution.Anewgroupshouldbeadded,thenungroupedandregroupedasadifferentgroupnode.Thisgetsaroundtheproblemofcopynodesinsteadofduplicatenodes.GroupnodesaremostoftenusedinthedefaultBlenderfile,thatwaycommonlyusedeffectscanbedonequickly.

ConclusionIwouldliketoencourageyoutoexplorethe

varioussettingsandusesforthenodes.Also,visitthesupportforumsforvariousreferenceschematicswhichcanhelpyouunderstandthemathematicalandgraphicalfunctionalityofeachnode.Forpracticalpurposes,theCompositorisaverypowerfultoolandshouldn'tbeconsideredaglorifiedSequenceryoucandoalotmorewiththisthanyoucouldeverdowiththeSequencer.Infact,Iwouldn'tbeabitsurprisedifyouneverusetheSequenceragain!

ThishasbeenabriefdescriptionoftheCompositor,whichisonlyhalfoftheNodewindow.Thereismoretolearn,suchastheinterface,the

Materialnodes,andthevariouswaysinwhichthesenodescanbeusedtogether.

Again,Iencourageeachusertopracticeusingnodesandlearntheinsandoutsofthistool.Havefun!


Blending ACompositorNodeOverview

35Know How - Index Of Reflection


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IndexofRefraction

Refractionoccurswhentheenergyofanincominglightwavematchesthenaturalvibrationfrequencyoftheelectronsinamaterial.Thelightwave

penetratesdeeplyintothematerial,andcausessmallvibrationsintheelectrons.Theelectronspassthesevibrationsontotheatomsinthematerial,andtheysendoutlightwavesofthesamefrequencyastheincomingwave.But,thisalltakestime.

Thepartofthewaveinsidethematerialslowsdown,whilethepartofthewaveoutsidetheobjectmaintainsitsoriginalfrequency.Thishastheeffectofbendingtheportionofthewaveinsidetheobjecttowardwhatiscalledthenormalline,animaginarystraightlinethatrunsperpendiculartothesurfaceoftheobject.Thedeviationfromthenormallineofthelightinsidetheobjectwillbelessthanthedeviationofthelightbeforeitenteredtheobject.

Theamountofbending,orangleofrefraction,ofthelightwavedependsonhowmuchthematerial

slowsdownthelight.Diamondswouldnotbesoglitteryiftheydidnotslowdownincominglightmuchmorethan,say,waterdoes.Diamondshaveahigherindexofrefractionthanwater,whichistosaythattheyslowdownlighttoagreaterdegree.

Oneinterestingnote

aboutrefractionisthatlightofdifferentfrequencies,orenergies,willbendatslightlydifferentangles.Let'scomparevioletlightandredlightwhentheyenteraglassprism.Becausevioletlighthasmoreenergy,ittakeslongertointeractwith

theglass.Assuch,itissloweddowntoagreaterextentthanawaveofredlight,andwillbebenttoagreaterdegree.Thisaccountsfortheorderofthecolorsthatweseeinarainbow.Itisalsowhatgivesadiamondtherainbowfringesthatmakeitsopleasingtotheeye.

DefinitionofIndexofRefractiontakenfromhttp://science.howstuffworks.com/light12.htmForamoretechnicaldescriptionyoucheckouttheexplanationathttp://en.wikipedia.org/wiki/Refractive_index

Nowwhyisthisimportant?Whencreatingmaterials,youneedtotakeIndexofRefractionintoaccount.Otherwise,yourmaterialswillnotbeconvincing.AndwiththenewtransmissivityfeatureaddedinthelastreleaseinadditiontotheIORsettingspanelalreadyinplace,blenderiscapableofconvincingIORvalues.

HereisalistofIORvaluesforyourreference.Thisimageisrathersmall,foraclearercopypleasecheckthepdfincludedwiththisissue.


KnowHow IndexOfReflection

IndexOfReflection

-by Sandra Gilbert

36Know How - Educational Resources
http://en.wikipedia.org/wiki/Refractive_indexhttp://science.howstuffworks.com/light12.htmhttp://www.blenderart.org/


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Thelastyearhasseenamajorincreaseinuserdocumentation.Withthearrivalofnewbooksinseverallanguages,downloadablemanualsandclassbooks/courses,learningBlenderhasbecomeeasierthanever.Letstakealookatwhatiscurrentlyavailableforoureducationalenjoyment.

BooksIntroducingCharacterAnimationwithBlenderbyTonyMullen,willsoonbefinishedandisnowavailableforpre-orderatAmazon.com.Itis432pagesandisanidealstartingpointforanybodyinterestedincreatingengaging,convincingcharacteranimation,givingathoroughandpracticalintroductiontothefunctionalityofBlender.

ItcomeswithacompanionDVDthatincludesthecompleteBlenderinstallationexecutableforWindows,Mac,andLinux;theshortfilm"ElephantsDream";alltheBlenderandsourcefilesusedtoproducetheexamplesandtutorialsinthebook;extensivelinksfortutorialsandBlender-relatedresources;andothervaluableOpenSourcesoftwarediscussedinthebook,includingthepopularBlenderPeoplescript.

La3DlibreavecBlender(Frenchmanual)byOlivierSarajaisavailablein

France.Itisaround356pages,featuringsomecolorplatesbywellknownartistsofthecommunity(StefanZsolt,Robertt,Harkyman).

Blender3D-GuiadoOsorio(Brazilian/Portuguesemanual)byAllanBrito.ThebookisaimedbothatthebeginningandtheadvancedBlenderuseranditcounts448pages.

BlenderBeginnersBible(Japanesemanual),byShinichiTasakiwasreleasedinSeptember.BlenderBeginnersBibleisaimedatthebeginningBlenderuser,coveringallthenewfeaturesandtoolsthathavebeenaddedtoBlendersincethelastJapanesebookwasreleasedin2003.

Aprendeen24HorasBlender&YafrayDisenoGrafico3DconSoftwareLibre(SpanishBlender2.41Manual)

http://www.boxel.info/morcy/index.php?entry=entry060805-185712Theprintedbook(orPDFversion)isactuallyacompilationofthetutorialsfromthecourse'AnimationforCommunication'whichwastaughtattheEscuelaSuperiordeInformaticaofCastilla-LaManchaUniversityinSpain,in2005/2006,byCarlosGonzalezMorcillo

CourseWork/GuidedTutorials

BlenderBasicsbyJimisthesecondeditionofBlenderBasics;hisclassroomtutorialbook.Itisaverythorough,readytouseguideof118pages.

NealHirsigfromTuftsUniversityofferscompletecoursematerialsforTuftsUniversity3DDesignclasscanbefoundathttp://ocw.tufts.edu/Course/28ortheBlackboardcoursesiteat:http://blackboard.tufts.eduUserword:blenderPassword:blender.Thereisalinktothecoursesitelistedunder"MyCourses"onthehomepagedisplayedafterlogin.TheBlackboardsiteisnotavailabledailyfrom1:00AM-2:00AMEasternStandardTime.

Thecoursecontainsweeklylearningunitsconsistingofoverahundredvideotutorialsandsome25PDFtutorials.Allassociatedfilesincludingcompletedtutorialscanbedownloaded.ThevideotutorialsareinstreamingRealMediaformatandrequirebroadbandorDSLaccess.Thesitealsoincludes4courseprojectsandexamplesofpriorstudentwork.

Nealinvitescommentsonthecoursematerialandcanbereachedatnhirsig@tufts.edu

OfficialDocumentationhttp://mediawiki.blender.org/index.php/Main_PageUser'sManualGameEngineDocumentationGlossaryQuickStartNoobtoProwikibookBlenderSummerofDocumentation


KnowHow EducationalResources
http://ocw.tufts.edu/Course/28http://mediawiki.blender.org/index.php/Main_Pagehttp://www.blenderart.org/


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IInntteerreesstteeddiinnwwrriittiinnggaarrttiicclleessffoorrBBlleennddeerrAArrttMMaaggaazziinnee??

1. Weacceptthefollowing:TutorialsexplainingnewBlenderfeatures,3dconcepts,techniquesorarticlesbasedoncurrentthemeof themagazine.

ReportsonusefulBlenderevents,throughouttheworld.

Cartoonsrelatedtoblenderworld.InterviewsofwellknownBlenderheads.

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Galleria 38
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LaBarge-Gamer

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GuilhermeLopes-Coca

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SalvadorGraciaBernal-Hormijas

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ScootMorrison-GavinsToyRobot

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ZoltanMiklosi-AirSurfing

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ZoltanMiklosi-Janine

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ZoltanMiklosi-Jenny

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GeorgeM-Coffeexp

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p g

Issue8January2007

Theme:CarModelingMegaSpecial!!

ModelingCars

ModelingTyres

CarPaintandmore...

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BlenderArt Magazine - 07 - Blender Materials