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Sound Actors

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Overview

Unreal Engine 3 provides several different types of actors that can be used to produce or modify ambient sounds within the level.

AmbientSound Actor

AmbientSound Actors are placed in maps to trigger SoundCues. When Actor Classes\Keypoint\AmbientSound is highlighted in the Generic Browser, these actors can be added virtually anywhere within the map by right clicking on desired location in any of the browser windows and selecting Add AmbientSound Here.

This Actor is largely used for triggering ambient looping sounds but it can also trigger non-looping sounds. When listener enters the radii defined in the SoundCue Editor the Actor is trigger once. If the Looping Node is utilized, it'll play repeatedly within the radii and respond to all properties defined in the SoundCue. If the Looping Node is not utilized the audio file will trigger once when listener enters radii.

The only controllable parameters on this actor are Pitch and Volume. The Radii must be defined in the SoundCue and there isn't a graphic representation of it in the editor. Use this actor when the flexibility of the SoundCue Editor to create complex sounds is more desirable than radii control\visibility. If you want to trigger the same Cue in multiple locations with different radii settings you'll need to create duplicate Cues for each instance.

AmbientSoundSimple Actor

The functionality of the AmbientSoundSimple Actor is similar to that of the AmbientSound Actor only instead of triggering SoundCues it triggers audio files directly. So in many ways this Actor is more similar to AmbientSound Actors found in previous Unreal engines.

This allows per Actor control over Attenuation, Spatialization, Radii, and Modulation. Relative Volume and Pitch adjustments are accomplished by using Volume Modulation and Pitch Modulation. The Min\Max Radii can be seen in the editor graphically as spheres and can be adjusted in real-time by click dragging the Red\Green\Blue Actor arrows.

AmbientSoundNonLoop Actor

AmbientSoundNonLoop Actors are placed in maps to trigger Non-Looping sounds randomly within a particular radius. When listener enters the radius it'll continue triggering sounds as defined in the Actor until listener exits the radii. As with AmbientSoundSimple this Actor triggers audio files directly.

• Delay Time controls the Minimum and Maximum amount of silence between triggers in seconds. Each time an audio file is triggered it'll randomly pick a delay time between that range.
• Volume Modulation + Pitch Modulation are used to define overall Actor Volume + Pitch
• Sound Slots are added for each Wav file by clicking the small green icon located on the right side of the SoundSlots tab. Each Sound Slot features per slot volume, pitch, and weight properties. Weight controls the probability a Sound Slot will be triggered relative to other Sound Slots in the Actor.
• The `Wave' slot located at the bottom of the Actors window should be ignored and not used.
• The Min\Max Radii can be seen in the editor graphically as spheres and can be adjusted in real-time by click dragging the Red\Green\Blue Actor arrows.

All AmbientSoundSimple + AmbientSoundNonLoop Actors selected in a map.

ReverbVolume

If you make any reverb volume changes, they will not work in realtime in the editor. You need to rebuild the geometry of the sub-level that contains your ReverbVolumes when you make ANY changes to the reverb volume(s).

AmbientSoundSpline Actor

In AmbientSoundSpline the sound location is not given in one point. The whole spline can be treated as a sound source. Virtual speaker position is estimated based on set of points on a spline (those points are generated automatically) and listener's position. To create (for example) a noise of a river only one AmbientSoundSpline's instance is needed.

AmbientSoundSimpleSpline Actor

AmbientSoundSimpleSpline allows to put many sounds along the spline. Each sound is in a slot. Slot has defined range of sound on spline. In editor bounds of range are represented by bigger light violet points on spline (they can be dragged). The currently edited slot can be changed using Edited Slot variable.

• Red point represents listener's position (draggable).
• Red circle represents listener's hearing scope.
• Blue point shows the virtual speaker's position.

Points on spline:

• White - spline curve control points.
• Red(only for AmbientSoundSimpleSpline) - points without any sound defined.
• Green - points inside the listener's scope.
• Light violet - points with a sound defined.

Spline curve:

• To move a control point grab it using left mouse button.(First control point is always at actor's location.)
• To remove a control point grab it and press backspace.
• To add a new control point grab the last one and press period.