book

Learning C# by Developing Games with Unity - Seventh Edition

by Harrison Ferrone

November 2022

Beginner

466 pages

9h 55m

English

Packt Publishing

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Who this book is forWhat this book coversTo get the most out of this bookGet in touch
Getting the most out of this book – get to know your free benefits Technical requirementsGetting started with Unity 2023Using macOSCreating a new projectNavigating the editorUsing C# with UnityWorking with C# scriptsIntroducing the Visual Studio editorOpening a C# fileBeware of naming mismatchesSyncing C# filesExploring the documentationAccessing Unity’s documentationLocating C# resourcesSummaryPop quiz—dealing with scripts
Defining variablesNames are importantVariables act as placeholdersUnderstanding methodsMethods drive actionsMethods are placeholders tooIntroducing classesA common Unity classClasses are blueprintsCommunication among classesWorking with commentsSingle-line commentsMulti-line commentsAdding commentsPutting the building blocks togetherScripts become componentsA helping hand from MonoBehaviourUnity application lifecycleHero’s trial—MonoBehaviour in the Scripting APISummaryPop quiz—C# building blocks
Writing proper C#Debugging your codeUnderstanding variablesDeclaring variablesType and value declarationsType-only declarationsUsing access modifiersWorking with typesCommon built-in typesType conversionsInferred declarationsCustom typesNaming variablesUnderstanding variable scopeIntroducing operatorsArithmetic and assignmentsDefining methodsDeclaring methodsNaming conventionsMethods as logic detoursSpecifying parametersSpecifying return valuesUsing return valuesHero’s trial—methods as argumentsDissecting common Unity methodsThe Start() methodThe Update() methodSummaryPop quiz—variables and methods
Selection statementsThe if-else statementUsing the NOT operatorNesting statementsEvaluating multiple conditionsThe switch statementPattern matchingFall-through casesPop Quiz 1—if, and, or butCollections at a glanceArraysIndexing and subscriptsMultidimensional arraysRange exceptionsListsAccessing and modifying listsDictionariesWorking with dictionary pairsPop Quiz 2—all about collectionsIteration statementsfor loopsforeach loopsLooping through key-value pairswhile loopsTo infinity and beyondSummary
Introducing OOPDefining classesInstantiating class objectsAdding class fieldsUsing constructorsDeclaring class methodsDeclaring structsUnderstanding reference and value typesReference typesValue typesIntegrating the object-oriented mindsetEncapsulationInheritanceBase constructorsCompositionPolymorphismApplying OOP in UnityObjects are a class actAccessing componentsAccessing components in codeDrag and dropSummaryPop quiz—all things OOP
A game design primerGame design documentsThe Hero Born one-pagerBuilding a levelCreating primitivesThinking in 3DMaterialsWhite-boxingEditor toolsHero’s trial—putting up drywallKeeping the hierarchy cleanWorking with PrefabsLighting basicsCreating lightsLight component propertiesAnimating in UnityCreating animations in codeCreating animations in the Unity Animation windowRecording keyframesCurves and tangentsSummaryPop quiz—basic Unity features
Managing player movementMoving the player with the Transform componentUnderstanding vectorsGetting player inputMoving the playerScripting camera behaviorWorking with the Unity physics systemRigidbody components in motionColliders and collisionsPicking up an itemUsing Collider triggersCreating an enemyHero’s trial—all the Prefabs!Physics roundupSummaryPop quiz—player controls and physics
Adding jumpsIntroducing enumerationsUnderlying typesWorking with layer masksShooting projectilesInstantiating objectsAdding the shooting mechanicManaging object build-upCreating a game managerTracking player propertiesThe get and set propertiesUpdating item collectionCreating a GUIDisplaying player statsWin and loss conditionsPausing and restarting the game with using directives and namespacesSummaryPop quiz – working with mechanics
Navigating 3D space in UnityNavigation componentsSetting up enemy agentsMoving enemy agentsProcedural programmingReferencing the patrol locationsMoving the enemyEnemy game mechanicsSeek and destroy: changing the agent’s destinationLowering player healthDetecting bullet collisionsUpdating the game managerRefactoring and keeping it DRYSummaryPop quiz—AI and navigation

Access modifiersConstant and read-only propertiesUsing the static keywordRevisiting methodsOverloading methodsref parametersout parametersIntermediate OOPInterfacesAbstract classesClass extensionsNamespace conflicts and type aliasingSummaryPop quiz—leveling up
Introducing stacksPopping and peekingCommon methodsWorking with queuesAdding, removing, and peekingUsing HashSetsPerforming operationsIntermediate collections roundupQuerying data with LINQ LINQ basicsLambda expressionsChaining queriesTransforming data into new typesSimplifying with optional syntaxSummaryPop quiz—intermediate collections
Introducing data formatsBreaking down XMLBreaking down JSONUnderstanding the filesystemWorking with asset pathsCreating and deleting directoriesCreating, updating, and deleting filesWorking with streamsManaging your Stream resourcesUsing StreamWriter and StreamReaderCreating an XMLWriterAutomatically closing streamsSerializing dataSerializing and deserializing XMLSerializing and deserializing JSONData roundupSummaryPop quiz—data management
Introducing genericsGeneric classesGeneric methodsConstraint type parametersAdding generics to Unity objectsDelegating actionsCreating a debug delegateDelegates as parameter typesFiring eventsCreating and invoking eventsHandling event subscriptionsCleaning up event subscriptionsHandling exceptionsThrowing exceptionsUsing try-catchSummaryPop quiz—intermediate C#
Diving deeperRemembering your object-oriented programmingDesign patterns primerApproaching Unity projectsUnity features we didn’t coverNext stepsC# resourcesUnity resourcesUnity certificationsHero’s trial—putting something out into the worldSummary
How to unlock these benefits in three easy stepsNeed help?
Chapter 1: Getting to Know Your EnvironmentPop quiz—dealing with scriptsChapter 2: The Building Blocks of ProgrammingPop quiz—C# building blocksChapter 3: Diving into Variables, Types, and MethodsPop quiz—variables and methodsChapter 4: Control Flow and Collection TypesPop quiz 1—if, and, or butPop quiz 2—all about collectionsChapter 5: Working with Classes, Structs, and OOPPop quiz—all things OOPChapter 6: Getting Your Hands Dirty with UnityPop quiz—basic Unity featuresChapter 7: Movement, Camera Controls, and CollisionsPop quiz—player controls and physicsChapter 8: Scripting Game MechanicsPop quiz—working with mechanicsChapter 9: Basic AI and Enemy BehaviorPop quiz—AI and navigationChapter 10: Revisiting Types, Methods, and ClassesPop quiz—leveling upChapter 11: Specialized Collection Types and LINQPop quiz—intermediate collectionsChapter 12: Saving, Loading, and Serializing DataPop quiz—data managementChapter 13: Exploring Generics, Delegates, and BeyondPop quiz—intermediate C#

Content preview from Learning C# by Developing Games with Unity - Seventh Edition

9 Basic AI and Enemy Behavior

Virtual scenarios need conflicts, consequences, and potential rewards to feel real. Without these three things, there’s no incentive for the player to care about what happens to their in-game character, much less continue to play the game. And while there are plenty of game mechanics that deliver on one or more of these conditions, nothing beats an enemy that will seek you out and try to end your session.

Programming an intelligent enemy is no easy task, and often goes hand in hand with long working hours and frustration. However, Unity has built-in features, components, and classes we can use to design and implement AI systems in a more user-friendly way. These tools will push the first playable iteration of