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

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

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

Blueprint ↔ Wwise Wiring

Create GameParameter in Wwise (e.g., "Player_Speed")
In Blueprint, call SetRTPCValue("Player_Speed", velocity)
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

$ARGUMENTS