Sound is a great way to provide feedback to player actions and events, background sounds can also give your scene more context and improve the player’s immersion into it.
Note: Keep in mind that sounds are only heard by players who are standing within the parcels that make up the scene where the sound was generated, even if they would otherwise be in hearing range. Players can also turn off sounds on their settings.
Supported sound formats vary depending on the browser, but it’s recommended to use .mp3.
.wav files are also supported but not generally recommended as they are significantly larger.
To play a sound, you need the following:
Entityto use for the sound location.
AudioSourcecomponent, added to that entity.
AudioClipobject, referenced by that component.
// Create entity const cube = new Entity() // Create AudioClip object, holding audio file const clip = new AudioClip("sounds/carnivalrides.mp3") // Create AudioSource component, referencing `clip` const source = new AudioSource(clip) // Add AudioSource component to entity cube.addComponent(source) // Play sound source.playing = true
When creating an
AudioClip object, you need to provide the path to the location of the sound file.
The sound file must be inside the project folder. In the example above, the audio file is located in a
sounds folder, which is located at root level of the scene project folder.
Tip: We recommend keeping your sound files separate in a
/soundsfolder inside your scene.
Each entity can only have a single
AudioSource component, that can only have a single
AudioClip. This limitation can be easily overcome by including multiple invisible entities, each with their own sound.
If you set the
playing property of an
AudioSource component to false, the file is stopped. This means that if you later set
playing to true again, the sound file will begin from the start again.
To keep a sound playing in a continuous loop, set the
loop field of the
AudioSource component to true before you start playing it.
source.loop = true source.playing = true
Looping sounds is especially useful for adding background music or other background sounds.
You can use the
playOnce() function to play a sound once from start to finish.
You can set the
volume property of the
AudioSource component to change the volume of a sound.
The volume can be a number from 0 to 1.
source.volume = 0.5
Note: Of course, the volume of a sound is also affected by the distance from the audio source.
Reuse sound objects
A great way to save processing power is to use a same
AudioClip object on many
Suppose you have a large amount of balls bouncing around in your scene, and you want to hear a thump sound every time two of them collide. You can add an
AudioSource component to each ball, and use a single
AudioClip object on all of these.
You can stream audio from a URL. This is useful to play music directly from an internet radio, or stream a conference into your scene.
The audio in the source must be in one of the following formats:
aac. The source must also be an https URL (http URLs aren’t supported), and the source should have CORS policies (Cross Origin Resource Sharing) that permit externally accessing it. If this is not the case, you might need to set up a server to act as a proxy and expose the stream in a valid way.
To add sound into your scene, simply add an entity with an
const streamSource = new Entity() streamSource.addComponent( new AudioStream( "https://icecast.ravepartyradio.org/ravepartyradio-192.mp3" ) ) engine.addEntity(streamSource) streamSource.getComponent(AudioStream).playing = true
Note: The streamed sound isn’t positional, it will be heard at a consistent volume throughout your entire scene. If a player steps out of the scene, they will not hear the streaming at all.
Set the volume of the
AudioStream component by changing its
AudioStream component on or off by setting its
playing property to true or false.