ShooterCore Game Logic Dissection

ShooterCore defines a lot more functionality than it shows off. In addition to the one map it provides, it is also used by ShooterMaps to showcase more maps and experiences.

In this high level game logic dissection we’ll take a look at what makes the game do what it does. This isn’t going to get into details of animation, menus, music or other aspects of the game. This is purely focused on the logic.

Experience: B_ShooterGame_Elimination

The L_ShooterGym map activates the B_ShooterGame_Elimination experience.

• Activate ShooterCore GameFeature Plugin
  • Mainly useful when other plugins want to use this experience

Pawn Data: HeroData_ShooterGame

• Pawn Class: B_Hero_ShooterMannequin
  • Very important class that warrants its own dissection
• Tag Relationships: TagRelationships_ShooterHero
  • This config helps determine which abilities can be used and when
• Input Config: InputData_Hero
• Camera Mode: CM_ThirdPerson

Pawn Ability Set: AbilitySet_ShooterHero

Adds default ShooterCore hero abilities to the pawn, maps which abilities should activate for which input tags.

• Abilities: GA_Hero_Jump, GA_Hero_Death, GA_Hero_Dash, GA_Emote, GA_QuickbarSlots, GA_ADS, GA_Grenade, GA_DropWeapon, GA_Melee, GA_SpawnEffect, LyraGameplayAbility_Reset
• Effects: GS_IsPlayer (sets Lyra.Player tag)

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Action Set: LAS_ShooterGame_SharedInput

Adds input bindings and key mappings pertinent to ShooterCore (e.g. show leaderboard, throw grenade, melee attack, etc)

• Input Mapping: IMC_ShooterGame_KBM
• Input Config: InputData_ShooterGame_Addons

Action Set: LAS_ShooterGame_StandardComponents

LyraPlayerController injections:

Component	Parent Class	Tick Group	Scope
B_NiagaraNumberPopComponent	ULyraNumberPopComponent_NiagaraText	During Physics	Client
NameplateManagerComponent	UControllerComponent	During Physics	Client

Controller injections: (Player + AI both)

Component	Parent Class	Tick Group	Scope
B_QuickBarComponent	ULyraQuickBarComponent	During Physics	Client + Server

B_Hero_ShooterMannequin injections:

Component	Parent Class	Tick Group	Scope
NameplateSource	ULyraQuickBarComponent	During Physics	Client

Action Set: LAS_ShooterGame_StandardHUD

• Layout: W_ShooterHUDLayout
• Widgets:

Slot ID	Widget	Note
HUD.Slot.EliminationFeed	W_EliminationFeed
HUD.Slot.Equipment	W_QuickBar
HUD.Slot.TopAccolades	W_AccoladeHostWidget
HUD.Slot.Reticle	W_WeaponReticleHost
HUD.Slot.PerfStats.Graph	W_PerfStatContainer_GraphOnly
HUD.Slot.PerfStats.Text	W_PerfStatContainer_TextOnly
HUD.Slot.LeftSideTouchInputs	W_OnScreenJoystick_Left
HUD.Slot.RightSideTouchInputs	W_OnScreenJoystick_Right
HUD.Slot.RightSideTouchInputs	W_FireButton	DUPLICATE SLOT ID
HUD.Slot.RightSideTouchRegion	W_TouchRegion_Right
HUD.Slot.LeftSideTouchRegion	W_TouchRegion_Left

Action Set: EAS_BasicShooterAccolades

Interestingly this is the only place where injections are made to base Engine code rather than to ModularGameplayActors-derived classes.

This action set is also the only one with an EAS_ prefix rather than LAS_ which I imagine is intended to illustrate that this is intentionally referring to GameStateBase rather than LyraGameStateBase for these particular injections.

GameStateBase injections:

Component	Parent Class	Tick Group	Scope
B_ElimChainProcessor	UElimChainProcessor < UGameplayMessageProcessor	During Physics	Server only
B_ElimStreakProcessor	UElimStreakProcessor < UGameplayMessageProcessor	During Physics	Server only
AssistProcessor (C++)	UGameplayMessageProcessor	During Physics	Server only
B_AccoladeRelay	UGameplayMessageProcessor	During Physics	Client + Server

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Experience Ability Sets

LyraPlayerState injections:

Component	Parent Class
AbilitySet_Elimination	ULyraAbilitySet

Ability Set: AbilitySet_Elimination

Ability	Input Tag
GA_ShowLeaderboard_TDM	InputTag.Ability.ShowLeaderboard
GA_AutoRespawn

Experience Component Injection

LyraGameState injections:

Component	Parent Class	Tick Group	Scope
B_TeamDeathMatchScoring	B_ShooterGameScoringBase	During Physics	Client + Server
B_MusicManagerComponent_Elimination	B_MusicManagerComponentBase	During Physics	Client
B_ShooterBotSpawner	ULyraBotCreationComponent	During Physics	Server
B_TeamSetup_TwoTeams	ULyraTeamCreationComponent	During Physics	Server
B_TeamSpawningRules	UTDM_PlayerSpawningManagmentComponent	Pre Physics	Server

Controller injections: (Player + AI both)

Component	Parent Class	Tick Group	Scope
B_PickRandomCharacter	ULyraControllerComponent_CharacterParts	During Physics	Server

Experience Widgets

Slot ID	Widget
HUD.Slot.TeamScore	W_ScoreWidget_Elimination

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Game Logic

Logic from LyraGameState injections

B_TeamSetup_TwoTeams logic

• Teams to Create:
  • 1 = TeamDA_Red
  • 2 = TeamDA_Blue

B_TeamSpawningRules logic

• Try to find ALyraPlayerStart farthest from enemy teams

B_ShooterBotSpawner logic

• Num Bots to Create: 3
• Assign random bot names
• Bot Controller Class: B_AI_Controller_LyraShooter < ULyraPlayerBotController

B_AI_Controller_LyraShooter logic

• BeginPlay:
  • Wait for Experience Ready, then:
    • Run Behavior Tree = BT_Lyra_Shooter_Bot
  • Register OnDeathStarted custom event on pawn’s Lyra Health Component.OnDeathStarted event
• OnPossess event:
  • Start BrainComponent logic
  • Set AIPerception team ID
• OnUnPossess event:
  • Call OnDeathStarted custom event
• OnDeathStarted custom event:
  • Clear blackboard
  • Stop BrainComponent logic

B_TeamDeathMatchScoring logic

• Wait for Experience Ready, then:
  • Start Phase_Warmup game phase
    • Attach GameStarted custom event to end of Phase_Warmup game phase
• GameStarted custom event
  • Set game state like max # kills to win, max time to end game
  • Start timer to tick game clock every second
    • Calls CountDown custom event each second
  • If lots of players then enable data layer with extra spawn points
  • Reset all players
  • Reset all other misc actors
• CountDown custom event
  • update game clock
  • when out of time, call HandleVictory function
• OnEliminationScored function
  • Base class calls this each time someone is killed
  • Child class calls HandleVictory if one team reaches the winning threshold
• HandleVictory function
  • Send GameplayCue.ShooterGame.UserMessage.MatchDecided cue
  • Start Phase_Post_Game game phase
• (via base class)
  • Listen for Gameplay Cues, update score
    • Lyra.Elimination.Message
    • Lyra.Assist.Message

B_MusicManagerComponent_Elimination logic

• Set Is Menu = False
• Begin Play:
  • Set mx_System as Game State Music System
  • Listen for Lyra.Elimination.Message cues, call Receive Player Death function
  • Listen for Lyra.Damage.Taken.Message cues, if local player then call Receive Weapon Fire function
• Every Tick:
  • Set LookDir audio controller parameter
  • Set Alpha Mvmt audio parameter based on current move speed
  • Set Intensity audio parameter
• Receive Player Death function sets max alpha 1.0
• Receive Weapon Fire function sets alpha based on weapon fire strength

Logic from LyraPlayerController injections

B_NiagaraNumberPopComponent logic

Base class ULyraNumberPopComponent

• When damage is done/taken, briefly display a damage number

NameplateManagerComponent logic

• Keep track of all actors needing nameplates
• Use W_Nameplate UI widget

Logic from Controller injections

B_PickRandomCharacter Logic

This component is injected into all Controllers for both Players and AI.

• BeginPlay event:
  • AddCharacterPart randomly choose either B_Manny or B_Quinn body parts
  • Minor bug: Does NOT call Parent BeginPlay
    • Seems like it will only be problematic if/when you allow users to change which pawns they possess

B_QuickBarComponent logic

Base class ULyraQuickBarComponent

• Manage the 3 quick bar slots
  • which equipment is in which slot
• Allow swapping which equipment is active

Logic from B_Hero_ShooterMannequin injections

NameplateSource logic

• Begin Play:
  • Broadcast to other players that self should have a nameplate
  • Register for Gameplay.Message.Nameplate.Discover gameplay cues
    • When receiving one, respond and register self
• End Play:
  • Broadcast to other players to remove self as a nameplate object

Logic from GameStateBase injections

B_ElimChainProcessor logic

Base class UElimChainProcessor

• Keep track of how many players were eliminated since we last died.

B_ElimStreakProcessor logic

Base class UElimStreakProcessor

• Keep track of long streaks of kills (5, 10, 15, 20).

AssistProcessor logic

• Keep track of number of kill assists this player has.

B_AccoladeRelay logic

• Listen for Lyra.ShooterGame.Accolade gameplay cues
• Do stuff RE accolades