sound-cues

name	sound-cues
display_name	Sound Cue Editor
description	Create and modify SoundCue assets — add/connect nodes (mixer, random, delay, attenuation, modulator, etc.) and set audio properties (SoundCueService). Use when the user asks to create a Sound Cue, build a SoundCue node graph, or wire audio playback logic.
vibeue_classes	["SoundCueService"]
unreal_classes	["SoundCue","SoundNodeWavePlayer","SoundNodeRandom","SoundNodeMixer","SoundNodeConcatenator","SoundNodeModulator","SoundNodeAttenuation","SoundNodeLooping","SoundNodeDelay","SoundNodeSwitch","SoundNodeEnveloper","SoundNodeDistanceCrossFade","SoundNodeBranch","SoundNodeParamCrossFade","SoundNodeQualityLevel"]
keywords	["sound cue","sound node","wave player","random node","mixer","audio graph","sound design","SoundCue"]
related_skills	["asset-management"]

🧠 Brains complement: IF an unreal-engine-skills-manager tool (external MCP) exists in this session, call it with {action: "load", skill: "audio-and-metasounds"} for UE domain knowledge on this topic — correct APIs, architecture, best practices — and treat it as the rubric for any review / "best practices" question. If no such tool is available (e.g. running under Claude Code or Codex without that MCP), skip this line entirely and proceed with this skill alone — do NOT attempt the call.

Wrong skill for MetaSound assets? If the user asked about MetaSound, MS_ assets, or UMetaSoundSource, load the metasounds skill instead (via GetSkills / AgentSkillToolset). SoundCue and MetaSound are completely separate systems — do not use SoundCueService for MetaSound tasks.

Sound Cue Editor Skill

Service Access

import unreal
svc = unreal.SoundCueService()

---

Audio Flow Direction

Audio flows FROM leaves TOWARD root.

[WavePlayer] ──> [Random] ──> [Mixer] ──> [ROOT]
                                ^
                    [WavePlayer2] ──────┘

• connect_nodes(parent, child, slot) means: child provides audio INTO parent at that input slot.
• set_root_node(index) makes that node the final output (what you hear).

---

Critical Rules

⚠️ Bool Properties — b prefix stripped in Python

UE strips the b prefix from bool UPROPERTY names in Python:

C++ / UPROPERTY	Python attribute
bSuccess	success
bIsRootNode	is_root_node
bLooping	is_looping
bStreaming	is_streaming

⚠️ Node indices are positional and may shift

list_nodes() returns nodes in graph order — indices can change if new nodes are added. Always call list_nodes() to get current indices before connecting or modifying nodes.

⚠️ Quality Level node has a fixed slot count

add_quality_level_node creates a node whose input-slot count is governed by the project's audio quality levels (AudioQualitySettings), not by an argument — there is no num_inputs param. In a default/skeleton project this is often a single slot, so connect_nodes(..., slot=1) returns False. If a cue must select between sounds per scalability bucket, confirm the project defines multiple quality levels first; otherwise only slot 0 is wireable.

⚠️ New-cue defaults: volume_multiplier is 0.75, not 1.0

A freshly created empty cue reports volume_multiplier = 0.75 (the engine USoundCue default), pitch_multiplier = 1.0. Do not assert 1.0 for volume on a new cue — read it back instead.

⚠️ connect_nodes parameter order

# parent receives audio FROM child at slot
svc.connect_nodes(cue_path, parent_index, child_index, input_slot)

# CORRECT: WavePlayer(0) feeds into Random(1) at slot 0
svc.connect_nodes('/Game/MyCue', 1, 0, 0)

# WRONG: don't confuse child/parent order

---

Workflows

Create a Simple SoundCue

import unreal
svc = unreal.SoundCueService()

# Create the asset (optionally wire an initial WavePlayer)
r = svc.create_sound_cue('/Game/Audio/SC_Footstep', '')
assert r.success, r.message

# Add a WavePlayer node
r = svc.add_wave_player_node('/Game/Audio/SC_Footstep', '/Game/Audio/Footstep_01', -250, 0)
assert r.success

# Set it as the root (output)
nodes = svc.list_nodes('/Game/Audio/SC_Footstep')
svc.set_root_node('/Game/Audio/SC_Footstep', nodes[0].node_index)

# Save
svc.save_sound_cue('/Game/Audio/SC_Footstep')

Random from Multiple Waves

import unreal
svc = unreal.SoundCueService()
cue = '/Game/Audio/SC_Footsteps'

svc.create_sound_cue(cue, '')

# Add 3 wave players
for i, wave in enumerate(['/Game/Audio/Step_01', '/Game/Audio/Step_02', '/Game/Audio/Step_03']):
    svc.add_wave_player_node(cue, wave, -400, i * 150)

# Add a Random node to select one
svc.add_random_node(cue, -150, 150)

nodes = svc.list_nodes(cue)
# nodes[0..2] = WavePlayers, nodes[3] = Random
random_idx = next(i for i, n in enumerate(nodes) if 'Random' in n.node_class)
for i in range(3):
    svc.connect_nodes(cue, random_idx, i, i)  # each wave into random

svc.set_root_node(cue, random_idx)
svc.save_sound_cue(cue)

Mixer (parallel blend)

import unreal
svc = unreal.SoundCueService()
cue = '/Game/Audio/SC_Ambient'

svc.create_sound_cue(cue, '')
svc.add_wave_player_node(cue, '/Game/Audio/Wind', -400, 0)
svc.add_wave_player_node(cue, '/Game/Audio/Rain', -400, 150)
svc.add_mixer_node(cue, 2, -150, 75)   # 2 inputs

nodes = svc.list_nodes(cue)
wave0 = next(i for i, n in enumerate(nodes) if 'WavePlayer' in n.node_class and i == 0)
wave1 = next(i for i, n in enumerate(nodes) if 'WavePlayer' in n.node_class and i != wave0)
mixer = next(i for i, n in enumerate(nodes) if 'Mixer' in n.node_class)

svc.connect_nodes(cue, mixer, wave0, 0)
svc.connect_nodes(cue, mixer, wave1, 1)
svc.set_root_node(cue, mixer)
svc.save_sound_cue(cue)

Volume / Pitch / SoundClass

svc.set_volume_multiplier('/Game/Audio/SC_Explosion', 1.5)
svc.set_pitch_multiplier('/Game/Audio/SC_Explosion', 0.9)
svc.set_sound_class('/Game/Audio/SC_Explosion', '/Game/Audio/SC_SFX')

---

API Reference

Asset Lifecycle

Method	Returns	Notes
create_sound_cue(path, wave_path)	FSoundCueResult	wave_path='' for empty cue
duplicate_sound_cue(src_path, dst_path)	FSoundCueResult	copy a cue to a new path
delete_sound_cue(path)	bool	deletes the asset from disk
get_sound_cue_info(path)	FSoundCueInfo	node count, root index, vol, pitch, duration
save_sound_cue(path)	bool	saves to disk

Node Creation — all return FSoundCueResult

Method	Node Type	Special params
add_wave_player_node(path, wave_path, x, y)	Leaf — plays a SoundWave	wave_path optional
add_random_node(path, x, y)	Picks one child randomly	—
add_mixer_node(path, num_inputs, x, y)	Blends children in parallel	num_inputs 1–32
add_concatenator_node(path, num_inputs, x, y)	Plays children in sequence	num_inputs 2–32
add_modulator_node(path, x, y)	Random pitch/volume variance	—
add_attenuation_node(path, x, y)	Spatial attenuation (graph node)	—
add_looping_node(path, x, y)	Loops its child	—
add_delay_node(path, x, y)	Adds a delay before playing	—
add_switch_node(path, x, y)	Routes by integer parameter	—
add_enveloper_node(path, x, y)	Volume/pitch envelope over time	—
add_distance_cross_fade_node(path, num_inputs, x, y)	Crossfades by distance	num_inputs 2–32
add_branch_node(path, x, y, bool_param='')	Routes by bool parameter; True(0) False(1) Unset(2)	optional param name last
add_param_cross_fade_node(path, num_inputs, x, y)	Crossfades by named float param	num_inputs 2–32
add_quality_level_node(path, x, y)	One input per quality level	slot count = project quality levels (see note)

Node Management

Method	Returns	Notes
list_nodes(path)	TArray<FSoundCueNodeInfo>	index, class, children, is_root_node
connect_nodes(path, parent, child, slot)	bool	child feeds audio INTO parent
disconnect_node(path, parent_index, slot)	bool	break a single input link
set_root_node(path, index)	bool	sets cue output node
set_wave_player_asset(path, index, wave_path)	bool	reassign wave on existing node
remove_node(path, index)	bool	delete a node from the graph
move_node(path, index, x, y)	bool	reposition a node in the graph
get_node_property(path, index, prop_name)	FString	read any node UPROPERTY
set_node_property(path, index, prop_name, value)	bool	write any node UPROPERTY

Cue-Level Settings

Method	Returns	Notes
set_volume_multiplier(path, vol)	bool	—
set_pitch_multiplier(path, pitch)	bool	—
set_sound_class(path, class_path)	bool	—
set_attenuation(path, att_path)	bool	att_path='' to clear
get_attenuation(path)	FString	returns asset path or ''
set_concurrency(path, conc_path, clear=False)	bool	conc_path='' + clear=True to clear all
get_concurrency(path)	TArray<FString>	list of assigned concurrency asset paths

FSoundCueNodeInfo fields

n.node_index      # int — position in list_nodes array
n.node_class      # str — e.g. "SoundNodeWavePlayer"
n.node_title      # str — display name
n.pos_x, n.pos_y  # float — graph position
n.is_root_node    # bool — True if this node is SoundCue.FirstNode
n.child_indices   # list[int] — indices of connected children (-1 = unconnected slot)

SoundWave Utilities

Method	Returns	Notes
get_sound_wave_info(sw_path)	FSoundWaveInfo	duration, sample rate, channels, looping, streaming
import_sound_wave(file_path, asset_path)	FSoundCueResult	import .wav/.mp3 from disk
set_sound_wave_property(sw_path, prop, value)	bool	set any UPROPERTY by name

Common set_sound_wave_property property names:

PropertyName	Type	Example value
bLooping	bool	"true"
bStreaming	bool	"true"
VolumeMultiplier	float	"1.5"
PitchMultiplier	float	"0.9"
SubtitlePriority	float	"100.0"

FSoundWaveInfo fields

info.asset_path    # str
info.duration      # float — seconds
info.sample_rate   # int — Hz
info.num_channels  # int — 1=mono, 2=stereo
info.looping       # bool  (note: NOT is_looping — UE strips the 'b' only)
info.streaming     # bool  (note: NOT is_streaming)

FSoundCueResult fields

r.success      # bool
r.asset_path   # str
r.message      # str — human-readable status or error

Sample scripts (run via execute_python_code)

• scripts/create_sound_cue.txt — create a SoundCue (optionally from a wave) and add nodes.