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UE5-Modular-Game-Framework/docs/blueprints/10-adaptive/132_SS_AudioManager.md
Lefteris Notas 411edea8ce add blueprints
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132 — MetaSounds Audio Manager (SS_AudioManager)

Purpose

Single entry point for all audio playback in the framework. Every system routes sound through this Game Instance Subsystem instead of calling UGameplayStatics::PlaySound* directly. Owns 4 MetaSound buses (SFX, Ambience, Music, Dialogue) → Master Bus, manages room-based reverb zones with crossfade, handles per-category volume from player settings, and accepts gameplay-driven parameter modulation (heart rate, stress, fear, music intensity).

Dependencies

  • Requires: SS_SettingsSystem (105 — persistent volume settings), BPC_StateManager (130 — heart rate + vital signals), BPC_StressSystem (10 — stress tier), BPC_PacingDirector (98 — music intensity), BPC_HealthSystem (08 — player health for muffled audio), BPC_FearSystem (90 — fear audio modulation), DA_AudioSettings (134 — default config)
  • Required By: ALL systems that play audio, BP_RoomAudioZone (133 — room preset changes), WBP_SettingsMenu (57 — volume sliders), BPC_AudioAtmosphereController (95 — DEPRECATED, replaced by this)
  • Engine/Plugin Requirements: MetaSounds plugin (UE 5.5+ default audio engine), GameplayTags plugin

Class Info

Property Value
Parent Class GameInstanceSubsystem
Class Type Game Instance Subsystem
Asset Path Content/Framework/Audio/SS_AudioManager.uasset
Implements Interfaces (none)

1. Enums

E_AudioBusCategory — Audio Bus Categories (5 values)

Enum Name: E_AudioBusCategory
(DisplayName = "Audio Bus Category")

Values:
  SFX = 0         // Sound effects — spatial, occluded, surface-reactive
  Ambience = 1    // Environmental background — room tones, weather
  Music = 2       // Dynamic music — layers, intensity bands
  Dialogue = 3    // VO and character dialogue — ducking priority
  Master = 4      // Master output — overall volume

2. Structs

S_AudioBusConfig

Field Type Description
BusCategory E_AudioBusCategory Which bus this config applies to
DefaultVolume Float (0–1) Default volume (pre-settings)
MetaSoundSource UMetaSoundSource The MetaSound patch for this bus
bSpatialized Boolean Use 3D spatialization?
AttenuationSettings USoundAttenuation Distance falloff curve
MaxConcurrentSounds Integer Voice limiting per bus
DuckingPriority Integer 0=lowest, 100=highest (dialogue=100)
DuckAmount Float (0–1) How much to duck other buses when this bus plays
SettingsBindingTag GameplayTag Tag for settings lookup (e.g., Settings.Audio.SFXVolume)

S_RoomAcousticProfile

Field Type Description
RoomPresetName FName Identifier for this room preset
ReverbDensity Float (0–1) How dense the reverb reflections are
ReverbDecayTime Float (seconds) RT60 decay time
ReverbWetLevel Float (0–1) Wet/dry mix for reverb
ReflectionsDelay Float (ms) Pre-delay before reflections start
RoomSizeScale Float (0.5–3.0) Perceived room size
OcclusionMultiplier Float (0–1) How much walls occlude sound (0=fully open, 1=fully blocked)
LowPassCutoff Float (Hz) Low-pass filter cutoff (simulates wall filtering)
bApplyToSFX Boolean Apply this room to SFX bus?
bApplyToAmbience Boolean Apply this room to ambience bus?
bApplyToDialogue Boolean Apply this room to dialogue bus?
TransitionTime Float (seconds) Crossfade time when entering this room

3. Variables

Configuration (Instance Editable, Expose On Spawn)

Variable Type Default Category Description
BusConfigs Array<S_AudioBusConfig> [SFX, Ambience, Music, Dialogue] Audio Config Configuration per bus
RoomPresets Array<DA_RoomAcousticPreset> DefaultPresets Audio Config All room acoustic presets
DefaultRoomPreset DA_RoomAcousticPreset Outdoor Audio Config Fallback room preset
AudioSettings DA_AudioSettings Defaults Audio Config Data asset with volume defaults and bus config

Internal (Private / Protected)

Variable Type Default Category Description
ActiveRoomPreset DA_RoomAcousticPreset None Room Current room acoustic profile
PreviousRoomPreset DA_RoomAcousticPreset None Room Previous room (for crossfade)
RoomTransitionProgress Float 0.0 Room Crossfade progress 0→1
RoomTransitionDuration Float 0.0 Room Current transition time remaining
RoomZoneStack Array<DA_RoomAcousticPreset> Empty Room Push/pop stack for nested room zones
bIsMuted Boolean false State Global mute toggle
bIsPaused Boolean false State Global pause state
BusInstances Map<E_AudioBusCategory, UAudioComponent> Empty Bus Active bus audio components
ActiveSFXInstances Array<UAudioComponent> Empty SFX Pooled SFX playback instances
SFXPoolSize Integer 32 SFX Max concurrent SFX instances
bIsCrossfading Boolean false Room Room transition in progress
ActiveDialogueCount Integer 0 Dialogue Number of active dialogue lines

4. Functions

Public Playback Functions

PlaySFX → UAudioComponent

  • Description: Play spatial SFX through SFX bus at world location. Surface tag selects material impact variant.
  • Parameters:
    Param Type Description
    Sound UMetaSoundSource The MetaSound source to play
    Location FVector World position for spatialization
    SurfaceTag GameplayTag (optional) Physical surface tag for material EQ variant
  • Blueprint Authority: Any
  • Flow:
    1. Get or create SFX audio component from pool
    2. Set sound to SFXBus MetaSound source
    3. Set world location
    4. If SurfaceTag valid: set SurfaceEQ parameter on MetaSound
    5. Play audio component
    6. Return component reference

PlaySFX2D → UAudioComponent

  • Description: Play non-spatial SFX through SFX bus (UI sounds, heartbeat).
  • Parameters:
    Param Type Description
    Sound UMetaSoundSource The MetaSound source to play
  • Blueprint Authority: Any
  • Flow: Same as PlaySFX but without world location — 2D playback.

PlayAmbient → void

  • Description: Crossfade ambient layer on Ambience bus.
  • Parameters:
    Param Type Description
    Sound UMetaSoundSource Ambient layer MetaSound
    FadeIn Float (default 1.0) Fade-in duration in seconds
  • Blueprint Authority: Any
  • Flow:
    1. Get Ambience bus audio component
    2. Set new MetaSound source
    3. Fade volume from 0 to target over FadeIn seconds
    4. Route through current room reverb

StopAmbient → void

  • Description: Fade out current ambient layer.
  • Parameters:
    Param Type Description
    FadeOut Float (default 2.0) Fade-out duration in seconds
  • Blueprint Authority: Any

SetMusicLayer → void

  • Description: Set a music layer with intensity parameter.
  • Parameters:
    Param Type Description
    LayerIndex Integer Which music layer (0-3: Calm/Tense/Action/Climax)
    Sound UMetaSoundSource MetaSound source for this layer
    Intensity Float (default 0.5) Layer blend intensity 0-1
  • Blueprint Authority: Any

StopMusicLayers → void

  • Description: Fade out all music layers.
  • Parameters:
    Param Type Description
    FadeOut Float (default 2.0) Fade-out duration in seconds
  • Blueprint Authority: Any

PlayMusicStinger → void

  • Description: One-shot music stinger on Music bus (overrides layers temporarily).
  • Parameters:
    Param Type Description
    Stinger UMetaSoundSource Stinger MetaSound source
  • Blueprint Authority: Any

PlayDialogue → void

  • Description: Play dialogue line. Ducks other buses by configured amounts.
  • Parameters:
    Param Type Description
    DialogueSound UMetaSoundSource Dialogue MetaSound source
    Priority Integer (default 0) 0=Bark, 10=Quest, 100=Cinematic
  • Blueprint Authority: Any
  • Flow:
    1. If ActiveDialogueCount >= MaxConcurrentDialogue, check priority
    2. If new priority > lowest active: interrupt lowest, play new
    3. Apply ducking: SFX -6dB, Ambience -12dB, Music -18dB
    4. Route dialogue through Dialogue bus with spatialization

StopDialogue → void

  • Description: Stop current dialogue playback.
  • Parameters:
    Param Type Description
    FadeOut Float (default 0.5) Fade-out duration in seconds
  • Blueprint Authority: Any

Public Room Zone Functions

SetRoomPreset → void

  • Description: Begin room transition with smooth crossfade of reverb/occlusion parameters.
  • Parameters:
    Param Type Description
    Preset DA_RoomAcousticPreset The new room acoustic preset
  • Blueprint Authority: Any
  • Flow:
    1. Push current preset onto RoomZoneStack
    2. Set PreviousRoomPreset = ActiveRoomPreset
    3. Set ActiveRoomPreset = Preset
    4. Set RoomTransitionDuration = Preset.TransitionTime
    5. Set bIsCrossfading = true
    6. Fire OnRoomPresetChanged(PreviousPreset, Preset)
    7. Begin per-tick interpolation (see TickRoomTransition)

SetRoomPresetInstant → void

  • Description: Instant room switch — no crossfade. Used for void space entry, cutscenes.
  • Parameters:
    Param Type Description
    Preset DA_RoomAcousticPreset The new room preset to apply immediately
  • Blueprint Authority: Any

GetCurrentRoomPreset → DA_RoomAcousticPreset

  • Description: Returns the currently active room preset.
  • Parameters: (none)
  • Blueprint Authority: Any (Pure)

PopRoomPreset → void

  • Description: Restores the previous room from the zone stack. Called by BP_RoomAudioZone on overlap end.
  • Parameters: (none)
  • Blueprint Authority: Any

Public Settings / Control Functions

SetBusVolume → void

  • Description: Set volume for a specific bus category. Called from settings menu.
  • Parameters:
    Param Type Description
    Bus E_AudioBusCategory Which bus to adjust
    Volume Float (0–1) Target volume
  • Blueprint Authority: Any
  • Flow:
    1. Set float parameter Volume on the corresponding MetaSound bus
    2. Fire OnBusVolumeChanged
    3. If Bus == Master, scale all buses proportionally

GetBusVolume → Float

  • Description: Get current volume for a specific bus.
  • Parameters:
    Param Type Description
    Bus E_AudioBusCategory Which bus to query
  • Blueprint Authority: Any (Pure)

SetMasterMute → void

  • Description: Mute/unmute all audio globally.
  • Parameters:
    Param Type Description
    bMuted Boolean True to mute, false to unmute
  • Blueprint Authority: Any

SetPauseAll → void

  • Description: Pause/resume all audio (used when pause menu opens/closes).
  • Parameters:
    Param Type Description
    bPaused Boolean True to pause, false to resume
  • Blueprint Authority: Any
  • Flow:
    1. Set bIsPaused = bPaused
    2. Set Paused on all bus audio components
    3. Fire OnAudioPaused(bPaused)

UpdateGameplayParameter → void

  • Description: Set a gameplay-driven MetaSound float parameter on the relevant bus.
  • Parameters:
    Param Type Description
    ParameterName FName MetaSound parameter name (e.g., MusicIntensity)
    Value Float Parameter value
  • Blueprint Authority: Any

UpdateHeartRateAudio → void

  • Description: Drives heartbeat SFX tempo and breathing layer intensity from StateManager data.
  • Parameters:
    Param Type Description
    BPM Float Current heart rate in BPM (60-180)
    Signal E_PlayerVitalSignals Vital signal tier
  • Blueprint Authority: Any
  • Flow:
    1. Set HeartRateBPM parameter on SFX bus
    2. Set VitalSignal parameter (0-4 enum as int) on SFX bus
    3. If heartbeat SFX not already playing: start looping heartbeat MetaSound

UpdateFearAudio → void

  • Description: Drives fear-reactive audio modulation from StressSystem + FearSystem.
  • Parameters:
    Param Type Description
    FearLevel Float (0–1) Current fear intensity
    Tier E_StressTier Current stress tier
  • Blueprint Authority: Any
  • Flow:
    1. Set FearIntensity parameter on Ambience + SFX buses
    2. Set StressLevel parameter on Ambience + Music buses
    3. Apply fear effects: subtle pitch drop, reverb increase, random pan jitter

Internal Functions (Private)

InitializeBuses → void

  • Description: Create UAudioComponent for each bus category and attach MetaSound sources. Called during Initialize.
  • Flow:
    1. For each BusConfig in BusConfigs: a. Create UAudioComponent b. Set sound to BusConfig.MetaSoundSource c. Configure spatialization from BusConfig.bSpatialized d. Attach attenuation settings e. Store in BusInstances map
    2. Apply saved settings volumes to each bus
    3. Set ActiveRoomPreset = DefaultRoomPreset

TickRoomTransition → void

  • Description: Called on Tick — interpolates room reverb/occlusion/filter parameters during crossfade.
  • Parameters:
    Param Type Description
    DeltaTime Float Frame time
  • Flow:
    1. If !bIsCrossfading: return
    2. RoomTransitionProgress += DeltaTime
    3. If RoomTransitionProgress >= RoomTransitionDuration: clamp to 1.0, set bIsCrossfading = false
    4. Alpha = RoomTransitionProgress / RoomTransitionDuration
    5. Interpolate: ReverbDensity, ReverbDecayTime, ReverbWetLevel, ReflectionsDelay, RoomSizeScale, OcclusionMultiplier, LowPassCutoff between PreviousRoomPreset and ActiveRoomPreset
    6. Apply to relevant buses based on bApplyToSFX / bApplyToAmbience / bApplyToDialogue flags

GetOrCreateSFXInstance → UAudioComponent

  • Description: Pool management — reuse an idle SFX audio component or create a new one. If pool is full (32), cull the oldest instance.
  • Flow:
    1. Find first idle component in ActiveSFXInstances
    2. If found: return it
    3. If pool not full: create new, add to pool, return
    4. If pool full: stop oldest active instance, reuse it

ApplyRoomToBus → void

  • Description: Apply a room preset's reverb/occlusion/filter to a specific bus.
  • Parameters:
    Param Type Description
    Bus E_AudioBusCategory Target bus
    Preset DA_RoomAcousticPreset Room preset to apply

ApplySettingsToBus → void

  • Description: Read saved settings volume from SS_SettingsSystem and apply to the bus component.
  • Parameters:
    Param Type Description
    Bus E_AudioBusCategory Target bus

5. Event Dispatchers

Dispatcher Parameters Bind Access Description
OnRoomPresetChanged OldPreset: FName, NewPreset: FName Public Fired when room acoustic profile changes
OnBusVolumeChanged Bus: E_AudioBusCategory, Volume: Float Public Fired when a bus volume is adjusted
OnAudioPaused bPaused: Boolean Public Fired on pause/resume — for visual feedback
OnMasterMuteChanged bMuted: Boolean Public Fired when global mute toggles
OnDialogueStarted DialogueSound: UMetaSoundSource, Priority: Integer Public Fired when dialogue begins (for subtitle triggering)
OnDialogueEnded WasInterrupted: Boolean Public Fired when dialogue ends

6. Overridden Events / Custom Events

Event: Initialize

  • Description: Called when subsystem is created. Loads config, initializes buses, binds settings.
  • Flow:
    1. Load DA_AudioSettings if assigned
    2. Call InitializeBuses()
    3. Bind to SS_SettingsSystem.OnSettingChanged → route volume changes to SetBusVolume
    4. Enable tick (required for room transition interpolation)
    5. Apply saved settings volumes from persistent storage

Event: Deinitialize

  • Description: Cleanup all audio components and unbind delegates.
  • Flow:
    1. Stop all bus audio components
    2. Clear ActiveSFXInstances pool
    3. Unbind from SS_SettingsSystem
    4. Set all references to null

7. Blueprint Graph Logic Flow

Audio Playback Routing

flowchart TD
    A[Any System: PlaySound] --> B[SS_AudioManager.PlaySFX / PlayAmbient / PlayMusic / PlayDialogue]
    B --> C{Route by Category}
    C -->|SFX| D[SFX Bus MetaSound Source]
    C -->|Ambience| E[Ambience Bus MetaSound Source]
    C -->|Music| F[Music Bus MetaSound Source]
    C -->|Dialogue| G[Dialogue Bus MetaSound Source]
    D --> H[Room Zone Reverb]
    E --> H
    F --> H
    G --> H
    H --> I[Master Bus]
    I --> J[Player Settings Volume Sliders]
    J --> K[Audio Output]
    
    L[BPC_StateManager.HeartRate] -->|Parameter| D
    M[BPC_StressSystem.StressTier] -->|Parameter| E
    N[BPC_PacingDirector.IntensityBand] -->|Parameter| F
    O[BPC_AccessibilitySettings] -->|Volume Sliders| I

Settings Flow

sequenceDiagram
    participant SM as WBP_SettingsMenu
    participant SS as SS_SettingsSystem
    participant AM as SS_AudioManager
    participant Bus as MetaSound Bus

    SM->>SS: SetFloat(Settings.Audio.SFXVolume, 0.8)
    SS->>SS: Save to persistent settings
    SS->>AM: SetBusVolume(SFX, 0.8)
    AM->>Bus: Set Float Parameter 'Volume' = 0.8
    Bus->>Bus: Apply to output

    Note over AM: On game launch:
    AM->>SS: GetFloat(Settings.Audio.SFXVolume)
    SS->>AM: 0.8
    AM->>Bus: Set Float Parameter 'Volume' = 0.8

8. Mix Bus Architecture

┌─────────────────────────────────────────────────────┐
│                   MASTER BUS                         │
│  (MS_MasterBus)                                      │
│  - Master Volume (settings)                          │
│  - Limiter / Compressor                              │
│  - Global Mute                                       │
│  - Accessibility: Mono collapse, L/R balance         │
│                                                      │
│  ┌──────────────────────────────────────────────┐   │
│  │              SFX BUS (MS_SFXBus)              │   │
│  │  - 3D Spatialization                          │   │
│  │  - Per-source occlusion (line trace)          │   │
│  │  - Distance attenuation                       │   │
│  │  - Surface material EQ (concrete/metal/wood)  │   │
│  │  - Heart rate BPM → breathing blend param     │   │
│  │  - Max 32 concurrent voices                   │   │
│  │  - Ducking: -6dB when Dialogue active         │   │
│  │  Sub-inputs:                                   │   │
│  │    • WeaponFire (limit 8 voices)               │   │
│  │    • Footsteps (limit 4 voices per actor)     │   │
│  │    • Impacts (limit 8 voices)                  │   │
│  │    • UI SFX (2D, no spatialization)           │   │
│  └──────────────────────────────────────────────┘   │
│                                                      │
│  ┌──────────────────────────────────────────────┐   │
│  │           AMBIENCE BUS (MS_AmbientBus)         │   │
│  │  - Stereo (no 3D)                             │   │
│  │  - 4-layer crossfade (room tone, wind, drone) │   │
│  │  - Stress tier → layer blend weights          │   │
│  │  - Room reverb applied                        │   │
│  │  - Ducking: -12dB when Dialogue active        │   │
│  └──────────────────────────────────────────────┘   │
│                                                      │
│  ┌──────────────────────────────────────────────┐   │
│  │             MUSIC BUS (MS_MusicBus)            │   │
│  │  - Stereo (no 3D)                             │   │
│  │  - 4 intensity layers (Calm/Tense/Action/Climax)│  │
│  │  - PacingDirector.IntensityBand → layer blend │   │
│  │  - Stingers (one-shot overrides)              │   │
│  │  - Ducking: -18dB when Dialogue active        │   │
│  │  - Combat detected → crossfade to Action      │   │
│  └──────────────────────────────────────────────┘   │
│                                                      │
│  ┌──────────────────────────────────────────────┐   │
│  │          DIALOGUE BUS (MS_DialogueBus)         │   │
│  │  - 3D (for in-world dialogue)                 │   │
│  │  - Priority system (Cinematic > Quest > Bark) │   │
│  │  - Ducks all other buses                      │   │
│  │  - Lip-sync amplitude passthrough             │   │
│  │  - Radio/phone EQ preset toggle               │   │
│  │  - Max 2 concurrent dialogue voices           │   │
│  │  - Settings: DialogueVolume → bus volume      │   │
│  └──────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────┘

9. Settings Integration

Player-Facing Volume Sliders

Setting GameplayTag Bus Controlled MetaSound Parameter
Master Volume Settings.Audio.MasterVolume Master Bus Volume (0–1)
SFX Volume Settings.Audio.SFXVolume SFX Bus Volume (0–1)
Music Volume Settings.Audio.MusicVolume Music Bus Volume (0–1)
Ambience Volume Settings.Audio.AmbientVolume Ambience Bus Volume (0–1)
Dialogue Volume Settings.Audio.DialogueVolume Dialogue Bus Volume (0–1)

Accessibility Settings

Setting Effect
Mono Audio Collapse all buses to mono on Master Bus
Subtitle Background Opacity (UI — not audio, handled by WBP_AccessibilityUI)
Audio Cues for UI Play additional confirmation SFX on button press
Left/Right Balance Pan parameter on Master Bus (for single-ear players)
Visual Heartbeat Indicator Alternative to audio heartbeat for deaf players — UI pulse based on BPC_StateManager.CurrentHeartRate

10. Gameplay Parameter Modulation

MetaSound parameters driven by gameplay state:

Parameter Name Source System Bus Range Effect
HeartRateBPM BPC_StateManager (130) SFX 60–180 Controls heartbeat SFX tempo + breathing layer intensity
VitalSignal BPC_StateManager (130) SFX 0–4 (enum) Selects heartbeat sound variant (normal/elevated/critical/erratic)
StressLevel BPC_StressSystem (10) Ambience, Music 0–1 Blends tension layers, adds distortion
FearIntensity BPC_FearSystem (90) Ambience, SFX 0–1 Lowers pitch, increases reverb, random pan jitter
MusicIntensity BPC_PacingDirector (98) Music 0–1 (4 bands) Crossfades between Calm/Tense/Action/Climax layers
PlayerHealth BPC_HealthSystem (08) SFX 0–1 Low-pass filter on all SFX as health drops (muffled hearing)
IsUnderwater (Physics volume) Master bool Apply underwater EQ + muffled low-pass
CombatActive BPC_StateManager (130) Music bool Stinger trigger + immediate intensity ramp
TimeOfDay World state Ambience 0–1 (dawn→dusk) Ambient layer blend (day birds → night crickets)

11. Communication Matrix

Who Talks How What Is Sent
Any System SS_AudioManager.PlaySFX() UMetaSoundSource, FVector Location, GameplayTag SurfaceTag
Any System SS_AudioManager.PlaySFX2D() UMetaSoundSource (UI sounds)
Any System SS_AudioManager.PlayAmbient() UMetaSoundSource, Float FadeIn
Any System SS_AudioManager.SetMusicLayer() Integer LayerIndex, UMetaSoundSource, Float Intensity
Any System SS_AudioManager.PlayDialogue() UMetaSoundSource, Integer Priority
BP_RoomAudioZone (133) SS_AudioManager.SetRoomPreset() DA_RoomAcousticPreset
WBP_SettingsMenu (57) SS_SettingsSystem.SetFloat() → SS_AudioManager.SetBusVolume() E_AudioBusCategory, Float Volume
BPC_StateManager (130) SS_AudioManager.UpdateHeartRateAudio() Float BPM, E_PlayerVitalSignals
BPC_StressSystem (10) SS_AudioManager.UpdateFearAudio() Float FearLevel, E_StressTier
BPC_PacingDirector (98) SS_AudioManager.UpdateGameplayParameter("MusicIntensity") Float 0–1
BPC_HealthSystem (08) SS_AudioManager.UpdateGameplayParameter("PlayerHealth") Float 0–1
SS_AudioManager Dispatcher: OnRoomPresetChanged OldPreset: FName, NewPreset: FName
SS_AudioManager Dispatcher: OnBusVolumeChanged Bus: E_AudioBusCategory, Volume: Float
SS_AudioManager Dispatcher: OnAudioPaused bPaused: Boolean
SS_AudioManager Dispatcher: OnDialogueStarted UMetaSoundSource, Integer Priority (for subtitle system)
SS_AudioManager WBP_AccessibilityUI (45) Heart rate BPM for visual heartbeat indicator

12. Migration: Replacing Deprecated BPC_AudioAtmosphereController (95)

Old (BPC_AudioAtmosphereController) New (SS_AudioManager)
PlayOneShotSFX(Sound, Location) SS_AudioManager.PlaySFX(Sound, Location)
PlayAmbientSound(Sound, FadeIn) SS_AudioManager.PlayAmbient(Sound, FadeIn)
SetMusicLayer(LayerIndex, Sound, Volume) SS_AudioManager.SetMusicLayer(LayerIndex, Sound, Intensity)
PlayDialogue(DialogueSound) SS_AudioManager.PlayDialogue(DialogueSound, Priority)
SetReverb(Reverb, WetLevel) SS_AudioManager.SetRoomPreset(Preset) via BP_RoomAudioZone
SetOcclusion(Intensity) Automatic — per-source line trace in MetaSound bus
FearReactiveAudioUpdate(Fear, Threshold) SS_AudioManager.UpdateFearAudio(Fear, Tier)
HandleRoomChange(RoomAcousticPreset) BP_RoomAudioZone.OnActorBeginOverlap
ActiveAudioPreset / TargetAudioPreset SS_AudioManager.ActiveRoomPreset
Master/SFX/Music/Ambient/DialogueVolumeModifier SS_AudioManager.SetBusVolume() bound to SS_SettingsSystem

Phase-Out Strategy

  1. Phase 14a: Create SS_AudioManager + BP_RoomAudioZone + all MetaSound patches (CURRENT)
  2. Phase 14b: Update all 129 systems to call SS_AudioManager instead of raw UGameplayStatics::PlaySound*
  3. Phase 14c: Convert all USoundBase references to UMetaSoundSource in Data Assets
  4. Phase 14d: Remove BPC_AudioAtmosphereController (95) from build

13. Validation / Testing Checklist

  • PlaySFX(Sound, Location) spawns at correct world position with spatialization
  • PlaySFX2D(Sound) plays without spatialization (UI sounds)
  • PlayAmbient(Sound) crossfades ambient layer smoothly
  • SetMusicLayer(idx, Sound, intensity) blends music layers correctly
  • PlayDialogue(Sound, Priority) ducks other buses by correct amounts
  • BP_RoomAudioZone on overlap → SetRoomPreset transitions reverb smoothly
  • Nested room zones use stack correctly (push/pop)
  • Room transition crossfade interpolates reverb parameters
  • SS_SettingsSystem volume changes apply to correct bus
  • Master Mute silences all buses
  • Pause/Resume toggles all bus audio components
  • UpdateHeartRateAudio(BPM) modulates heartbeat tempo in MetaSound
  • UpdateFearAudio(0.8, Terrified) applies fear distortion
  • SFX pooling limits to 32 concurrent (oldest culled when full)
  • Dialogue priority system: higher priority interrupts lower
  • Accessibility mono audio collapses all buses
  • Accessibility L/R balance pans correctly on Master Bus
  • Edge case: Rapid room zone enter/exit doesn't cause audio glitches
  • Edge case: SS_AudioManager handles null MetaSound source gracefully
  • Edge case: Settings loaded before first sound plays (Init order)
  • Edge case: SetMasterMute(true) while crossfading — immediate mute

14. Reuse Notes

  • SS_AudioManager is the ONLY entry point for audio playback. Systems must never call UGameplayStatics::PlaySound* directly.
  • Game instance subsystem — exists for the entire game session. No per-level reinitialization needed.
  • SFX pool of 32 ensures no unbounded audio component creation. Reuse is automatic.
  • Room zone stack supports arbitrarily nested zones (room within building within cave).
  • All gameplay parameters are soft-referenced — if a source system (e.g., BPC_PacingDirector) is not present, UpdateGameplayParameter fails gracefully (log warning, no crash).
  • MetaSound sources can be hot-reloaded in-editor while the game is running for rapid sound design iteration.

Blueprint Spec: SS_AudioManager — Single entry point for all MetaSounds audio. Replaces BPC_AudioAtmosphereController (95). Architecture document: metasounds-audio-system.md