Unreal Engine Blueprint — Audio Logic & Asset Management

Handle Blueprint audio logic: game event detection, parameter wiring to MetaSounds/Wwise, asset scanning, and audio component setup.

Blueprint Audio Architecture

Blueprints are the WHEN layer — they detect game events and route parameters to audio systems:

Game Event (overlap, anim notify, input)
  → Blueprint Logic (detect, filter, transform)
    → Audio Action (play sound, set RTPC, post event)

Audio Blueprint Nodes

Playback

Node	Use	Spatial
PlaySound2D	UI, non-positional audio	No
PlaySoundAtLocation	One-shot 3D sound	Yes
SpawnSoundAtLocation	Persistent 3D sound (returns component)	Yes
SpawnSound2D	Persistent non-spatial	No

Dialogue

Node	Use
PlayDialogue2D	Non-spatial dialogue
PlayDialogueAtLocation	3D dialogue
SpawnDialogue2D	Persistent non-spatial dialogue
SpawnDialogueAtLocation	Persistent 3D dialogue

Mixing

Node	Use
SetSoundMixClassOverride	Override sound class volumes
ClearSoundMixClassOverride	Remove overrides
PushSoundMixModifier	Activate sound mix
PopSoundMixModifier	Deactivate sound mix
SetGlobalPitchModulation	Global pitch shift

Wwise (via AkAudio plugin)

Node	Use
PostEvent	Trigger Wwise event
SetRTPCValue	Set RTPC parameter
SetSwitch	Set switch group value
SetState	Set global state
PostTrigger	Post Wwise trigger

Game Event Patterns

Animation Notify → Sound

AnimNotify_Footstep
  → Line Trace Down (surface detect)
  → Set Switch (Surface = result)
  → PostEvent (Play_Footstep)

Overlap Volume → Ambient

OnBeginOverlap
  → Set RTPC (Ambient_Volume = 1.0)
OnEndOverlap
  → Set RTPC (Ambient_Volume = 0.0)

State Change → Weather Audio

OnWeatherChanged (Rain/Snow/Wind/Clear)
  → Set State (Weather = new_state)
  → Set RTPC (Wind_Intensity = value)

Damage → Impact Sound

OnHit / OnDamageReceived
  → Get Hit Result (surface, location, normal)
  → SpawnSoundAtLocation (location, rotation from normal)
  → Set Switch (Material = physical material)

Player Movement → Audio Params

Tick / Timer
  → Get Velocity → Vector Length
  → Set RTPC (Player_Speed = length)
  → Set RTPC (Player_Height = Z position)

Blueprint Scanning

The MCP plugin can deep-scan Blueprint graphs for audio-relevant nodes.

Scan Commands (via TCP plugin)

// List all project Blueprints
{"action": "list_assets", "class_filter": "Blueprint"}

// Scan one BP for audio nodes
{"action": "scan_blueprint", "asset_path": "/Game/BP_Player", "audio_only": true, "include_pins": true}

// List MetaSounds assets
{"action": "list_assets", "class_filter": "MetaSoundSource"}

// List all sound waves
{"action": "list_assets", "class_filter": "SoundWave"}

Batch Project Scan

python scripts/scan_project.py --full-export --import-db --rebuild-embeddings

Scans all BPs + MetaSounds graphs, imports to SQLite, rebuilds TF-IDF embeddings.

Scan Output Structure

{
  "blueprint_name": "BP_Player",
  "parent_class": "Character",
  "total_nodes": 245,
  "graphs": [
    {
      "graph_name": "EventGraph",
      "nodes": [
        {
          "type": "CallFunction",
          "function": "PlaySoundAtLocation",
          "is_audio": true,
          "pins": [...]
        }
      ]
    }
  ],
  "audio_summary": {
    "total_audio_nodes": 4,
    "functions": ["PlaySoundAtLocation", "SetRTPCValue"],
    "events": ["Play_Footstep"],
    "components": ["AkComponent"]
  }
}

Audio Detection Keywords

Sound, Audio, Ak, Wwise, MetaSound, RTPC, PostEvent, SoundCue, SoundWave, AudioComponent, AkComponent, SoundClass, SoundMix, Attenuation, Reverb, Submix, AudioVolume, AmbientSound, DialogueWave, SoundBase

Asset Types (class_filter values)

Filter	What
Blueprint	All Blueprints
WidgetBlueprint	UI Blueprints
AnimBlueprint	Animation Blueprints
MetaSoundSource	MetaSounds Source assets
MetaSoundPatch	MetaSounds Patch assets
SoundWave	Imported audio files
SoundCue	Legacy Sound Cue graphs
SoundAttenuation	Attenuation settings
SoundClass	Sound classification
SoundConcurrency	Concurrency rules
SoundMix	Mix presets
ReverbEffect	Reverb settings

Blueprint ↔ MetaSounds Wiring

Exposing MetaSounds Parameters to Blueprint

1. Add graph input in MetaSounds (Float, Int32, Trigger)
2. In Blueprint, get AudioComponent reference
3. Call SetFloatParameter / SetIntParameter / SetTriggerParameter

AudioComponent → SetFloatParameter("Cutoff", 2000.0)
AudioComponent → SetTriggerParameter("Fire")

Blueprint ↔ Wwise Wiring

1. Create GameParameter in Wwise (e.g., "Player_Speed")
2. In Blueprint, call SetRTPCValue("Player_Speed", velocity)
3. In Wwise, map RTPC to volume/pitch/filter curves

Available MCP Tools (Python)

Tool	Function
bp_search	Search knowledge DB for Blueprint nodes
bp_node_info	Get detailed node specification
bp_list_categories	List Blueprint node categories
bp_call_function	Execute allowlisted function via plugin
bp_list_assets	List project assets by class
bp_scan_blueprint	Deep-scan BP graph for audio nodes

UE4 → UE5 Conversion Map

UE4 Sound Cue	UE5 MetaSounds
Attenuation	UE.Attenuation interface
Concatenator	Trigger Sequence → Wave Players
Crossfade by Distance	Map Range + Crossfade
Delay	Trigger Delay
Doppler	Doppler Pitch Shift
Looping	Wave Player Loop=true
Mixer	Add (Audio)
Modulator	Random Get → Multiply
Oscillator	Sine/Saw/Square/Triangle
Random	Random Get
Sound Wave Player	Wave Player
Branch	Trigger Route
Continuous Modulator	LFO
Switch	Trigger Route + graph input

Source Files

• Blueprint tools: src/ue_audio_mcp/tools/blueprints.py
• Knowledge DB: src/ue_audio_mcp/knowledge/db.py (tables: blueprint_audio, blueprint_core, blueprint_nodes_scraped, project_blueprints)
• Tutorials: src/ue_audio_mcp/knowledge/tutorials.py
• Scan script: scripts/scan_project.py
• BP scraper: scripts/scrape_blueprint_api.py
• C++ scan command: ue5_plugin/UEAudioMCP/Source/UEAudioMCP/Private/Commands/QueryCommands.cpp

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