Sound Cue Reference

A reference guide for Sound Cues and the available Sound Nodes.

In Unreal Engine, a Sound Cue is an audio asset that encapsulates complex sound design tasks within a node graph. Sound Cues provide audio designers freedom to dynamically change parts of a sound effect's design by arranging and modifying Sound Nodes to create complex and interesting audio output.

In the Sound Cue Editor, a list of Sound Node types is provided within the Palette panel. Selecting a node in the Viewport panel will display the node's properties in the Details panel.

Sound Cue Editor Palette Panel

For more about working with Sound Cues, see the Sound Cue Editor and Sound Cue Editor UI documentation.

Named Parameters

In some Sound Nodes, you can declare a parameter by entering a new parameter name. When you enter a parameter name in a node, it will create a parameter with that name.

Named Parameter Example

You can name the parameter whatever you want. However, when you use an Audio Component Function to set the parameter's value, its In Name field must exactly match the Parameter Name you gave it.

You cannot set the values for a named parameter from within a Sound Cue. A recommended workflow would be:

  • Add a Sound Node.

  • Enter a name in the node Parameter Name field.

  • Call the relevant audio component function from within a Blueprint, or in code, using the appropriate Set [Name] Parameter function.

  • Add the same name to the In Name parameter. This will get the Sound Cue to respond as expected.

Set Wave Parameter Blueprint Example

The table below shows the nodes that can use named parameters, and the corresponding parameter setting functions.

Node Type

Corresponding Function

Branch

Set Boolean Parameter

Continuous Modulator

Set Float Parameter

Crossfade by Param

Set Float Parameter

SoundClass

Set Wave Parameter

Switch

Set Integer Parameter

Wave Param

Set Wave Parameter

Output Node

An Output node is required in every Sound Cue and works as an end point for the audio signal path in the node graph. The Output node's properties are relative and affect all of the audio output contained within the Sound Cue.

Output Sound Node

Property

Description

Memory

Prime on Load

If enabled, all connected Sound Waves will load into cache when this Sound Cue is loaded.

Disable Random Branch Culling

If enabled, all per-platform random node culling will be ignored.

Sound

Volume Multiplier

The base volume multiplier.

Pitch Multiplier

The base pitch multiplier.

Class

The Sound Class asset that this Sound Cue belongs to.

Attenuation

Override Attenuation

If enabled, the existing attenuation settings will be overridden with the provided values. See the Attenuation Node section of this page for more information.

Attenuation Settings

This can be set to an existing Sound Attenuation asset to utilize that asset's settings.

Effects

🞂 Source

Enable Bus Sends

If enabled, audio output will be sent to buses.

Source Effect Chain

The Source Effect Preset Chain asset to use for this Sound Cue.

Post-Effect Bus Sends

An array of buses to send audio output to if there are bus instances playing after the source effects are processed.

Pre-Effect Bus Sends

An array of buses to send audio output to if there are bus instances playing before source effects are processed.

🞂 Submix

Enable Base Submix

If enabled, sound will route to the Master Submix by default or to the Base Submix if defined. If disabled, sound will route ONLY to the Submix Sends and/or Bus Sends.

Base Submix

The Submix asset to use for this Sound Cue.

Enable Submix Sends

Enables sending audio output to additional submixes.

Submix Sends

An array of submixes which receive a prescribed amount (see Send Level) of this Sound Cue's audio output.

Voice Management

Virtualization Mode

Sets virtualization behavior to determine if a sound may revive and how it continues playing when culled or evicted due to looping sound limitations.

🞂 Priority

Subtitle Priority

The priority of the subtitle. Higher values will play instead of lower values.

Bypass Volume Scale for Priority

If enabled, bypasses volume weighting priority upon evaluating whether sound should remain active when max channel count is met.

Priority

This is used to determine whether sound can play or remain active if the channel limit is met. Higher values will play instead of lower values. Unless bypassed, value is weighted with the final volume of the sound to produce final runtime priority value.

🞂 Concurrency

Override Concurrency

If enabled, the existing concurrency settings will be overridden with the provided values. This allows the Concurrency Overrides values to be modified.

Concurrency Set

An array of concurrency settings to observe (if override is set to false). Sound must pass all concurrency settings to play.

🞂 Concurrency 🞂 Concurrency Overrides

Max Count

The maximum number of concurrent sounds allowed in this concurrency group.

Limit to Owner

If enabled, the concurrency settings are applied to the actor which played the sound. If the sound doesn't have an owning actor, it falls back to the global concurrency settings.

Resolution Rate

The concurrency resolution policy to use if max voice count is reached.

Retrigger Time

The amount of time (in seconds) to wait between different sounds. The sounds rejected from this will ignore virtualization settings.

Volume Scale

A ducking factor to apply per older voice instance, which compounds based on scaling mode, and optionally revives them as they stop according to provided attack/release times.

Volume Scale Mode

Designates how to scale voice volume based on the number of member sounds active in the group.

Duck Time

The amount of time (in seconds) to apply the ducking factor using the volume scalar.

Can Recover

If enabled, volume scaling can recover from the volume ducking behavior when concurrency group sounds stop. This is only available when Volume Scale Mode is set to Default.

Recover Time

The amount of time (in seconds) to recover from the volume scalar duck. This is only available when Can Recover is enabled.

Voice Steal Release Time

The amount of time (in seconds) to fade out if a sound is culled due to another sound in the group starting.

Advanced

Asset User Data

An array of user data stored with this asset.

Developer

Debug

If enabled, the attenuation shape is drawn when the sound is audible. For debugging purposes only.

Duration

The duration of the sound in seconds.

Max Distance

The maximum distance as determined by the attenuation settings.

Total Samples

The total number of samples (in the thousands). This is useful to analyze the relative size of a given asset. This value can also be viewed in the context menu that displays while hovering over a Sound Cue in the Content Drawer.

Attenuation Node

The Attenuation node controls volume for a sound based on the distance of the sound source from the listener.

The Attenuation Settings can be set to an existing Sound Attenuation asset or manually specified in the node's properties by enabling the Override Attenuation setting.

For an overview on attenuation and how it works, see the Sound Attenuation documentation.

Attenuation Sound Node

Property

Description

Attenuation

Attenuation Settings

This can be set to an existing Sound Attenuation asset to utilize that asset's settings.

Override Attenuation

If enabled, the existing attenuation settings will be overridden with the provided values.

Attenuation (Volume)

Enable Volume Attenuation

Enables or disables distance-based volume attenuation.

Attenuation Function

The type of attenuation function to use: Linear, Logarithmic, Inverse, Log Reverse, Natural Sound, or Custom

Attenuation At Max (dB)

(For Attenuation Function: Natural Sound) The attenuation volume at the falloff distance in decibels.

Falloff Mode

(For Attenuation Function: Natural Sound) Controls whether to continue attenuating, go silent, or hold the last volume value when beyond falloff bounds. Only editable if Attenuation At Max (dB) is set to a value of greater than -60dB.

Attenuation Shape

The shape for a non-custom attenuation function: Sphere, Capsule, Box, or Cone

Inner Radius

(For Attenuation Shape: Sphere) The radius that defines where sound attenuation begins (or where a custom attenuation curve begins). Sounds played at a distance less than this radius will not attenuate.

Capsule Half Height

(For Attenuation Shape: Capsule) The attenuation capsule's half height.

Capsule Radius

(For Attenuation Shape: Capsule) The attenuation capsule's radius.

Extents

(For Attenuation Shape: Box) The attenuation box's extents.

Cone Radius

(For Attenuation Shape: Cone) The attenuation cone's radius.

Cone Angle

(For Attenuation Shape: Cone) The attenuation cone's angle.

Cone Falloff Angle

(For Attenuation Shape: Cone) The attenuation cone's falloff angle.

Cone Offset

(For Attenuation Shape: Cone) The attenuation cone's offset.

Falloff Distance

The distance over which the volume attenuates.

Attenuation (Spatialization)

Enable Spatialization

When enabled, allow the input sound to be positioned in 3D space.

Spatialization Method

The method used to spatialize the sound:

  • Panning: The standard panning method for spatialization (linear or equal power method, as defined in project settings).

  • Binaural: If available, use the binaural spatialization method (requires headphones and is enabled by plugins).

Binaural Radius

The minimum radius to swap to non-binaural audio when a sound starts playing.

Non-Spatialized Radius

The distance from the origin where a sound is non-spatialized (2D). This prevents near-field audio from flipping as audio crosses the listener's position.

3D Stereo Spread

The world-space distance between left and right stereo channels when stereo assets are 3D spatialized.

Normalize 3D Stereo Sounds

When enabled, applies a -6 dB attenuation to stereo Assets that are 3D spatialized. This avoids clipping when Assets have a spread of 0.0 due to channel summing.

Spatialization Plugin Settings

An array of settings assets for spatialization plugins. As this is an array, multiple settings can be applied.

Attenuation (Occlusion)

Enable Occlusion

Enables real-time occlusion tracing.

Occlusion Trace Channel

The type of trace channel to use for audio occlusion checks.

Occlusion Low Pass Filter Frequency

The low-pass filter frequency (in Hz) that applies if the sound playing in this audio component is occluded. This will override the LowPassFilterFrequency specified in code or Blueprints. A frequency of 0.0 is the device sample rate and will bypass the filter.

Occlusion Volume Attenuation

The amount of volume attenuation to apply to occluded sounds.

Occlusion Interpolation Time

The amount of time in seconds to interpolate to the target Occlusion Low Pass Filter Frequency when a sound is occluded.

Use Complex Collision for Occlusion

Enables tracing against complex collisions when doing occlusion traces.

Occlusion Plugin Settings

An array of settings assets for occlusion plugins. As this is an array, multiple settings can be applied.

Attenuation (Submix)

Enables Submix Send

Enables submix sends based on distance.

Submix Send Settings

When this feature is enabled, the Submix Send Settings expand into a full set of parameters.

Attenuation (Reverb)

Enable Reverb Send

Enables adjusting reverb sends based on distance.

Reverb Send Method

The method used to control master reverb sends:

  • Linear: Reverb send based on linear interpolation between distance and send-level ranges.

  • Custom Curve: Reverb sending based on a supplied curve. This can be set directly in the Details Panel or to an external curve by clicking on the triangle beside the parameter name and using the expanded External Curve parameter options.

  • Manual: Reverb send level that uses the manual setting specified below. Useful for 2D sounds.

Reverb Min Send Level

The amount to send to master reverb when sound is located at a distance equal to the value specified.

Reverb Max Send Level

The amount to send to master reverb when sound is located at a distance equal to the value specified.

Reverb Min Send Distance

The minimum distance to send to the master reverb.

Reverb Max Send Distance

The maximum distance to send to the master reverb.

Reverb Plugin Settings

An array of settings assets for reverb plugins. As this is an array, multiple settings can be applied.

Attenuation (Focus)

Enable Listener Focus

This enables listener focus-based adjustments.

Focus Azimuth

The azimuth angle (in degrees) relative to the forward vector of the listener which defines the focus region of sounds. The sounds playing at an angle less than this will be in-focus.

Non Focus Azimuth

The azimuth angle (in degrees) relative to the forward vector of the listener which defines the non-focus region of sounds. The sounds playing at an angle greater than this will be out-of-focus.

Focus Distance Scale

The amount to scale the distance calculation for in-focus sounds. This can be used to make in-focus sounds seem closer or further away than they actually are.

Non Focus Distance Scale

The amount to scale the distance calculation for out-of-focus sounds. This can be used to make out-of-focus sounds seem closer or further away than they actually are.

Focus Priority Scale

The amount to scale the priority of sounds that are in-focus.

Non Focus Priority Scale

The amount to scale the priority of sounds that are not in-focus.

Focus Volume Attenuation

The amount to attenuate sounds that are in-focus. This can be overridden at the sound level.

Non Focus Volume Attenuation

The amount to attenuate sounds that are not in-focus. This can be overridden at the sound level.

Enable Focus Interpolation

This enables focus interpolation to smooth focus transition in and out.

Focus Attack Interp Speed

The scalar value used to increase interpolation speed upward to the target focus value. This option requires Enable Focus Interpolation to be enabled.

Focus Release Interp Speed

The scalar value used to increase interpolation speed downward to the target focus value. This option requires Enable Focus Interpolation to be enabled.

Attenuation (Priority)

Enable Priority Attenuation

Enables attenuation of sound priority based on distance.

Priority Attenuation Method

The method used to control priority attenuation:

  • Linear: Priority attenuation based on linear interpolation between distance and priority-attenuation ranges.

  • Custom Curve: Priority attenuation based on a supplied curve. This can be set directly in the Details Panel or to an external curve by clicking on the triangle beside the parameter name and using the expanded External Curve parameter options.

  • Manual: Priority attenuation based on the given Attenuation Priority value. This is useful for 2D sounds.

Priority Attenuation At Min Distance

The interpolated value to scale priority against when the sound is at the minimum priority attenuation distance from the closest listener.

Priority Attenuation At Max Distance

The interpolated value to scale priority against when the sound is at the maximum priority attenuation distance from the closest listener.

Priority Attenuation Min Distance

The minimum distance to attenuate priority.

Priority Attenuation Max Distance

The maximum distance to attenuate priority.

Attenuation Priority

(For Priority Attenuation Method: Manual) The priority level entered is static and does not change with distance.

Attenuation (Air Absorption)

Enable Air Absorption

Enables air absorption simulation by applying a filter with a cutoff frequency as a function of distance.

Min Distance Range

The minimum distance to apply an absorption low pass filter. Absorption frequency cutoff interpolates filter frequency ranges between Min Distance Range and Max Distance Range.

Max Distance Range

The maximum distance to apply an absorption low pass filter. Absorption frequency cutoff interpolates filter frequency ranges between Min Distance Range and Max Distance Range.

Low Pass Cutoff Frequency Min

The minimum range of the cutoff frequency (in Hz) for the low pass absorption filter.

Low Pass Cutoff Frequency Max

The maximum range of the cutoff frequency (in Hz) for the low pass absorption filter.

High Pass Cutoff Frequency Min

The minimum range of the cutoff frequency (in Hz) for the high pass absorption filter.

High Pass Cutoff Frequency Max

The maximum range of the cutoff frequency (in Hz) for the high pass absorption filter.

Enable Log Frequency Scaling

This enables perceptually linear frequency sweeping by applying a log scale to frequency values.

Absorption Method

The method used to map distance values to frequency absorption values:

  • Linear: The air absorption conforms to a linear distance function.

  • Custom Curve: The air absorption conforms to a custom distance curve. This can be set directly in the Details Panel or to an external curve by clicking on the triangle beside the parameter name and using the expanded External Curve parameter options.

Attenuation (Source Data Override)

Enable Source Data Override

Enables overriding WaveInstance data using source data override plugins.

Source Data Override Plugin Settings

An array of settings assets for source data override plugins. As this is an array, multiple settings can be applied.

Stereo files play evenly on the left and right channels, and attenuate to allow volume fades between the Radius Min and Radius Max values, but they are not spatialized.

Sound Cues that do not contain an Attenuation node are not localized, and play consistently at the Sound Cue volume setting.

Branch Node

The Branch node selects an input node based on the value of a named Boolean parameter of True, False or Parameter Unset.

Parameter Unset is the output that plays when the value of a named parameter has not been set. For example, if the parameter is saved as Name in the Branch node, but the user hasn't called SetBooleanParam(Name, [true or false]), the Sound Cue will use the Parameter Unset input pin, not the True or False pin.

For more information about named parameters, see the Named Parameters section of this page.

Branch Sound Node

Property

Description

Bool Parameter Name

The name of the Boolean parameter that determines which input node is used.

Concatenator Node

The Concatenator node is used to play sounds sequentially (for example, creating a simple BGM playlist that plays through a series of specified tracks). While this node handles sequential playback, it will also add a small delay between each asset.

Initially, this node has two input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

Concatenator Sound Node

Property

Description

Input Volume

An array which stores the volume multiplier for each attached input sound.

Continuous Modulator Node

The Continuous Modulator node provides a way to control named parameters for volume and pitch modulation in real time. A typical example would be using the velocity of a vehicle to correspond to the pitch of an engine sound. This modulator needs to be hooked up in code or Blueprint to work, and does not function on its own within the Sound Cue Editor. However, you can change pitch and volume from within the Sound Cue Editor.

By setting maximum and minimum values, you can determine the range of randomization.

The pitch and volume of the input sound will default to a uniform distribution, but you can change them in the Sound Cue Editor to any other type.

For more information about named parameters, see the Named Parameters section of this page.

Continuous Modulator Sound Node

Property

Description

Pitch Modulation Params

Parameter Name

The name of the sound instance parameter being used to manipulate pitch.

Default

The default pitch value used if no parameter is found.

Min Input

The minimum input pitch value. Values will be clamped to the [MinInput, MaxInput] range.

Max Input

The maximum input pitch value. Values will be clamped to the [MinInput, MaxInput] range.

Min Output

The minimum output pitch value. This value is scaled from the [MinInput, MaxInput] range to the [MinOutput, MaxOutput] range.

Max Output

The maximum output pitch value. This value is scaled from the [MinInput, MaxInput] range to the [MinOutput, MaxOutput] range.

Param Mode

The mode with which the parameter is applied:

  • Normal: Clamps input value to the range (MinInput, MaxInput), then maps to the range (MinOutput, MaxOutput).

  • Absolute: Same as Normal, except that the input value is treated as an absolute value.

  • Direct: Uses the input value directly, without scaling or reference to Min or Max input or output values.

Volume Modulation Params

Parameter Name

The name of the sound instance parameter being used to manipulate volume.

Default

The default volume value used if no parameter is found.

Min Input

The minimum input volume value. Values will be clamped to the [MinInput, MaxInput] range.

Max Input

The maximum input volume value. Values will be clamped to the [MinInput, MaxInput] range.

Min Output

The minimum output volume value. This value is scaled from the [MinInput, MaxInput] range to the [MinOutput, MaxOutput] range.

Max Output

The maximum output volume value. This value is scaled from the [MinInput, MaxInput] range to the [MinOutput, MaxOutput] range.

Param Mode

The mode with which the parameter is applied:

  • Normal: Clamps input value to the range (MinInput, MaxInput), then maps to the range (MinOutput, MaxOutput).

  • Absolute: Same as Normal, except that the input value is treated as an absolute value.

  • Direct: Uses the input value directly, without scaling or reference to Min or Max input or output values.

Crossfade by Distance Node

The Crossfade by Distance node provides the ability to fade between two or more input sounds based on the distance from the Sound Cue's origin to the listener.

For example, a gunshot heard at a distance will sound different from a gunshot up close. This node can calculate the distance the listener is from the shot and play the sound based on a short or long distance, or a mix of the two.

This node differs from the Attenuation node in that the sound will only play if it is within the minimum and maximum distance settings.

Sound Nodes can be connected directly to the Crossfade by Distance node inputs, but you can also add nodes between them for independent control per layer.

Initially, this node has two input pins. Add more pins by clicking Add input.

Crossfade by Distance Sound Node

Property

Description

Cross Fade Input

Fade in Distance Start

The distance from the listener's position at which the sound begins to be audible.

Fade in Distance End

The distance from the listener's position at which the sound reaches full volume.

Fade Out Distance Start

The distance from the listener's position at which the sound begins to fade out.

Fade Out Distance End

The distance from the listener's position at which the sound is no longer audible.

Volume

The maximum volume of the input sound.

If you want to hear the sound up close, then setting Fade in Distance Start to 0 might be a good option.

These values can be set independently for each attached sound.

Crossfade by Param Node

The Crossfade by Param node works similarly to the Crossfade by Distance node, except that the Crossfade by Param node provides a way for you to manipulate the value of a named parameter that controls the crossfade programmatically (with code or Blueprints).

Initially, this node has two input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

For more information about named parameters, see the Named Parameters section of this page.

Crossfade by Param Sound Node

Property

Description

Param Name

The name of the parameter used to control the crossfade.

Cross Fade Input

Fade in Param Value Start

The parameter value at which the sound begins to be audible.

Fade in Param Value End

The parameter value at which the sound reaches full volume.

Fade Out Param Value Start

The parameter value at which the sound begins to fade out.

Fade Out Param Value End

The parameter value at which the sound is no longer audible.

Volume

The maximum volume of the input sound.

If you want to hear the sound up close, then setting Fade in Param Value Start to 0 might be a good option.

Delay Node

The Delay node inserts a delay into the Sound Node chain to cause a pause before the input sound is passed to the output. The amount of the delay is a random value between the Delay Min and Delay Max values specified in the Details panel.

Delay Sound Node

Property

Description

Delay Min

Sets the lower bound of time in seconds for the pause.

Delay Max

Sets the upper bound in seconds.

Dialogue Player Node

The Dialogue Player node is a way to set up a Dialogue Wave asset to be played under specific conditions.

Since Dialogue Waves are expected to be used purely for spoken dialogue, the Dialogue Player node requires that you specify both the speaker and the targets of the dialogue being played. This allows the Dialogue Wave to play the correct audio Asset depending on the specific context, such as plurality, gendered language, or for localization purposes.

Dialogue Player Sound Node

Property

Description

Dialogue Wave

The Dialogue Wave that the node will play. Click the dropdown to browse for the Asset you want to use.

Context

Who is speaking, and to whom. Note that this can only be used once a valid Dialogue Wave is entered.

Looping

When enabled, the dialogue will play on a loop.

Doppler Node

The Doppler node simulates a Doppler effect, in which a sound's pitch changes based on the source's movement in relation to the listener. The pitch will increase as the source approaches the listener and will decrease as the source moves away.

A common real world example of this is the sound of a passing ambulance's siren.

Doppler Sound Node

Property

Description

Doppler Intensity

A multiplier value for how strongly the Doppler effect is heard. Increase the value to make the effect more pronounced.

Use Smoothing

When enabled, the node performs a smooth interpolation on the Doppler effect.

Smoothing Interp Speed

The speed at which the pitch scale is interpolated.

Enveloper Node

The Enveloper node creates an envelope where a sound's volume and pitch are manipulated over a specified time period via distribution curves. These curves can be edited using the embedded Curve Editors, or can be based on curves defined in an existing Float Curve Asset already in the Content Browser.

Optionally, the envelope can be set to loop a set number of times or even indefinitely.

You can use the properties in the Modulation category to randomize predefined values across set points on the envelope.

Enveloper Sound Node

Property

Description

Looping

Loop Start

The time in seconds where the envelope's loop begins.

Loop End

The time in seconds where the envelope's loop ends.

Duration After Loop

The time in seconds it takes the envelope to fade out after the last loop is completed.

Loop Count

The number of times the envelope will loop if looping is enabled and the envelope is not set to loop indefinitely.

Loop Indefinitely

If enabled, the envelope will continue to loop indefinitely regardless of Loop Count value.

Loop

If enabled, the envelope will loop using the specified loop settings.

Envelope

Volume Curve

The distribution curve that defines the volume envelope. This can be set directly in the Details Panel or to an external curve by clicking on the triangle beside the parameter name and using the expanded External Curve parameter options.

Pitch Curve

The distribution curve that defines the pitch envelope. This can be set directly in the Details Panel or to an external curve by clicking on the triangle beside the parameter name and using the expanded External Curve parameter options.

Modulation

Pitch Min

The minimum pitch for the input sound.

Pitch Max

The maximum pitch for the input sound.

Volume Min

The minimum volume for the input sound.

Volume Max

The maximum volume for the input sound.

Group Control Node

The Group Control node controls which sounds are played based on the number of active sounds, while giving priority to the first available group.

Initially, this node has two input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

Group Control Sound Node

Property

Description

Group Sizes

The maximum number of Sound Wave sources allowed for each group, minus 1 (the first Sound Wave Node is node 0).

Looping Node

The Looping node is used to loop sound indefinitely or a set number of times.

You can loop multiple audio files independently when used in conjunction with the Mixer node.

Looping Sound Node

Property

Description

Loop Count

The number of times to loop the input sound. This can only be edited if the Loop Indefinitely option is disabled.

Loop Indefinitely

When enabled, loop indefinitely regardless of the Loop Count value.

A Looping node should only be used for logical or procedural looping such as introducing a delay because these sounds will not play seamlessly. If you want a sound to loop seamlessly and indefinitely, use the Looping flag on the Wave Player node (see below) for the sound.

Mature Node

With the Mature node, you can flag input nodes as intended for mature audiences. This node uses the value of UEngine:bAllowMatureLanguage to determine whether input nodes should be played.

Initially, this node has two input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

Mature Sound Node

Mixer Node

The Mixer node defines how concurrent sounds in a Sound Cue are mixed together by providing volume control for each individual input.

Initially, this node has two input pins. Add more pins by clicking Add input.

Mixer Sound Node

Property

Description

Input Volume

The list of volumes to use for each of the input sounds, allowing normalization with different source volumes. The topmost input is represented by index 0 and each additional input is incremented in order.

Modulator Node

The Modulator node is used to randomize volume and pitch modulation. You can set maximum and minimum values to determine the range of randomization. When the Sound Cue is triggered, it randomly selects a value within that range.

To set a consistent level for volume or pitch, set the same values for both the minimum and maximum values. This node can also be used to adjust relative volumes of multiple Sound Wave nodes contained within a Sound Cue.

If the Modulator node is used in combination with the Looping node, it will randomize on the each Sound Cue trigger and not on each individual loop.

Modulator Sound Node

Property

Description

Pitch Min

Sets the minimum pitch for the input sound.

Pitch Max

Sets the maximum pitch for the input sound.

Volume Min

Sets the minimum volume for the input sound.

Volume Max

Sets the maximum volume for the input sound.

Oscillator Node

The Oscillator node is used to introduce continuous pitch and volume oscillation. This is useful when looping sounds to create a greater degree of ongoing movement.

By setting maximum and minimum values, you can determine the range of randomization.

Oscillator Sound Node

Property

Description

Modulate Volume

Enables volume modulation.

Modulate Pitch

Enables pitch modulation.

Amplitude Min

The minimum amplitude of the sine wave's modulation, centered around the value set by Center Min and Center Max. For example, an amplitude of 0.25 would oscillate between 0.75 and 1.25.

Amplitude Max

The maximum amplitude of the sine wave's modulation, centered around the value set by Center Min and Center Max. For example, an amplitude of 0.25 would oscillate between 0.75 and 1.25.

Frequency Min

The minimum frequency of the sine wave's modulation, with the value divided by two to equal to the hertz rate. For example, a frequency of 20 would oscillate at 10Hz.

Frequency Max

The maximum frequency of the sine wave's modulation, with the value divided by two to equal to the hertz rate. For example, a frequency of 20 would oscillate at 10Hz.

Offset Min

The minimum offset value into the sine wave, commonly called phase. The value entered here will be multiplied by 2π.

Offset Max

The maximum offset value into the sine wave, commonly called phase. The value entered here will be multiplied by 2π.

Center Min

Both Center Min and Center Max default to 0. Because the default is 0 (not 1), if the amplitude is .2, the sample will be multiplied between -.2 and .2 (instead of .8 and 1.2).

Center Max

See Center Min.

Quality Level Node

By default, there are no quality levels; the designer must add them to the Project Settings for the node inputs to populate. Once populated, node branching can be used to switch between various levels of SoundCue graph complexity. This provides a way for designers to use simpler SoundCue graphs for lower-powered platforms.

Quality Level Sound Node

The Quality Level node uses GameUserSettings AudioQualityLevel (or the editor override) to choose which branch to play.

At runtime, this node will only load into memory the Sound Waves connected to the branch that is selected.

Random Node

The Random node is used to randomly trigger a node from the list of connected input nodes. Weight values control the probability of a node being triggered relative to the other nodes connected to the Random node.

When an input node is selected randomly, the Sound Cue will play the entire data flow of that selected input.

Initially, this node has two input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

Random Sound Node

Property

Description

Weights

The list of weights for each input sound that determines the odds that a particular sound will be chosen. Each item in the Array can be assigned its own weight value.

Preselect at Level Load

If greater than 0, then upon each level load the specified number of inputs will be randomly selected and the rest will be removed. This can be used to cut down the memory usage of large randomizing cues. This setting does not apply during Play In Editor or Simulate; it applies only in game builds outside of Unreal Editor.

Should Exclude from Branch Culling

If set to true, this node will not be culled on load for platforms with a maximum amount of preloaded random branches set in the project settings.

Randomize Without Replacement

When enabled, the entire list of Sound Nodes will be exhausted before repeating a sound.

SoundClass Node

The SoundClass node provides a way to remap which Sound Class asset used with the input node.

For more information about named parameters, see the Named Parameters section of this page.

SoundClass Sound Node

Property

Description

Sound Class Override

The Sound Class Asset that will override the current Sound Class for the input node.

Switch Node

The Switch node selects an input node based on the value of a runtime integer parameter. The specified parameter must be declared in either code or Blueprints.

Initially, this node has four input pins. You may add more pins by clicking the Add input button on the node or remove pins by right-clicking them and selecting "Delete Input" from the context menu.

For more information about named parameters, see the Named Parameters section of this page.

Switch Sound Node

Property

Description

Switch

Int Parameter Name

The name of the integer parameter that determines which input is used.

Wave Param Node

The Wave Param node uses a named parameter to determine whether to play a different Sound Wave than the one feeding into the input pin. If the specified parameter is set to the name of a valid Sound Wave asset, that asset is played.

If an optional input node is connected and the named parameter is valid, the Wave Param will override the input node when the Sound Cue is played.

For more information about named parameters, see the Named Parameters section of this page.

A potential use for this node would be to play dynamic dialogue lines in between static blip sounds in order to simulate dialogue over a radio. In this way, the same Sound Cue can be reused to great effect.

Wave Param Sound Node

Property

Description

Wave Parameter Name

The name of the Sound Wave asset to play. If the Sound Wave asset specified does not exist, then the input node is evaluated to determine which sound to play instead.

Wave Player Node

The Wave Player node contains a reference to a Sound Wave asset to be played with the Sound Cue.

Wave Player Sound Node Looping Wave Player Sound Node

Property

Description

Sound Wave

The Sound Wave Asset to use in this node.

Looping

When enabled, the Sound Wave will play on a loop. Additionally, the node type displayed in the Sound Node Graph will be changed to "Looping Wave Player."

Add Comment

Comments can be added anywhere on the Sound Cue. They do not affect the output, but instead are used to call attention to or explain details in the node arrangements or uses.

The comment appears at the top of the frame. There is no limit to the length of the comment.

Add Comment Box

The comment frame's size can be changed by dragging the lines in the lower right corner and the position can be changed by dragging from anywhere else on the frame. Wherever positioned, it will appear behind the nodes.

If you move a comment box, it will bring any fully contained Sound Nodes along with it.

You can also add a comment by selecting multiple nodes, right-clicking a selected node, and then selecting Create Comment from Selection from the context menu.

Examples

Below are examples of more complex Sound Cue arrangements. You can click on each image to expand it.

This Sound Cue plays one sound if a parameter is set to true, and another if it is set to false.

This Sound Cue changes the Sound Classes of the Sound Waves.

This Sound Cue mixes together Sound Waves with a variety of properties, including attenuation, randomization, looping, and delays.

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