Sound

<Sound url> plays a sound file inside a World from when it mounts until the file ends or the component unmounts. Where you mount it decides where the player hears it from:

• Inside an Entity, the sound comes from the entity and grows quieter with distance from the camera.
• Anywhere else, the player hears it the same everywhere: an ambience, or a sting at the end of a round.

Its props are in SoundProps.

Roblox’s Sound works the same way: parented to a part it plays from there, and parented anywhere else it plays everywhere. Unity’s AudioSource and Godot’s AudioStreamPlayer3D are the placed kind; Godot’s AudioStreamPlayer is the everywhere kind.

When sound starts

A browser, a phone’s included, keeps a page silent until the player presses a key, clicks or touches the screen. A Sound mounted before that input starts playing on it. A one-off sound that a pickup or a footstep plays before that input does not play.

An iPhone with its ring switch set to silent plays no page sound, a game’s included, until the player sets it back to ring.

Footsteps and pickups

Two sounds need no Sound of their own:

• <Player footsteps> takes a list of files and plays one of them at random for each stride she walks. A stride is 1.67 metres, a third of her top speed of 5 m/s, which matches the three steps a second of her run.
• <Pickup sound> plays its file once, heard everywhere, as she takes the pickup. It does not play when the scene ends around a pickup nobody took.

The library’s sounds

sounds names the files in the shared asset library, which ship with the engine, and says what each one is for.

Sample

import {
    Entity,
    Pickup,
    Player,
    Sound,
    sounds,
    World,
} from "@daniel-zarinski/engine";

export function Run() {
    return (
        <World map="meadow">
            <Player footsteps={sounds.footstepsGrass} />
            <Sound url={sounds.forestAmbience} loop volume={0.5} />
            <Entity position={[0, 0, -3]}>
                <Pickup reward={1} sound={sounds.pickup} />
            </Entity>
        </World>
    );
}

Where it runs

Client. Sound changes nothing in the world; each player hears their own. Removing a game’s frame frees its audio with everything else it held, as the trust boundary says.