Sound

A Sound emitter plays a sound each time it emits: an impact, a whoosh, a hum that rises. It is made by transforming a Sound. Each emit plays a duplicate of the original. Its volume and its speed follow graphs over the play.

What it makes possible:

• An impact that never sounds the same twice. Emit 1, Speed 0.9, 1.15, Volume 0.4, 0.6.
• A whoosh that follows each projectile. A Sound emitter nested in the projectile’s RenderTemplate.
• An engine hum that rises. Looped on, Lifetime 3, a Speed graph from 0.6 to 1.4.
• A sting heard at full volume anywhere. 2D (local) on.

At a glance

Made from	A Sound
One particle is	One play of the sound
Emit count starts at	1
Modes	Emit only. There is no Animate mode.
Sections	Emission, Sound, Events, Advanced
Not present	Motion and Link. There is no Linger row and no Pool row.

What an emit does

Each emit makes a duplicate of the Sound kept in the RenderTemplate and plays it. The duplicate is removed when the play ends.

Playing starts once the audio has loaded, so the first note is not cut.

The Emit count is the number of plays started at the same moment. With Enabled on, Rate 10 starts ten plays each second, and the plays overlap.

Where the sound plays from

The first of these that applies decides the place:

Order	Case	The sound plays
1	2D (local) is on	With no position, at the same volume everywhere, and only on this client.
2	Emit Into is set	On that instance.
3	The emitter is nested in another emitter	On the parent particle, and travels with it.
4	The original Sound sits in a part or an Attachment	From that part or Attachment, following it.
5	None of the above	On the original Sound’s parent.

If the place is a Model, the sound plays from one of the Model’s parts. If no place is found, nothing plays.

A nested sound stops when its parent particle is removed, unless Emit Into is set.

Transform

Transform stops the original Sound. It keeps Volume and PlaybackSpeed as level graphs, and it keeps RollOffMinDistance, RollOffMaxDistance and Looped.

Emission

Row	Kind	Starts at	Unit	What it does
Enabled	Switch	Off		Starts plays at the Rate until switched off.
Rate	Number	10	Plays per second	How many plays start each second while Enabled is on, or during a Duration.
Lifetime	Two numbers	0	Seconds	How long each play lasts. 0 plays the sound once to its end.
Start At	Number	0	Seconds	The place in the sound where playing starts.
Looped	Switch	The Sound’s own		The sound repeats until the Lifetime ends.
2D (local)	Switch	Off		Plays the sound with no position. See Where the sound plays from.
Timescale	Graph	1		The speed at which the Lifetime and the two graphs advance. It does not change the pitch.

The Emit, Delay and Duration boxes on the HUD fire a Sound emitter as they fire any other. Emission and the HUD describes the shared rows in full.

Sound

Row	Kind	Starts at	Unit	What it does
Volume	Graph	The Sound’s own		The volume, over the Lifetime.
Speed	Graph	The Sound’s own		The playback speed, and with it the pitch, over the Lifetime.
Roll-off Min	Number	The Sound’s own	Studs	The distance at which the volume starts to fall.
Roll-off Max	Number	The Sound’s own	Studs	The distance beyond which the sound is not heard.

Volume and Speed are read in steps, Anim. Steps times over one Lifetime. The first value of each graph is set before the play starts.

A random spread gives each play one offset for its whole length. Speed 0.9, 1.1 gives each play a slightly different pitch.

Lifetime

The empty Lifetime box reads min, max (0 = clip length).

Lifetime	Result
0	The sound plays once to its end.
Above 0, shorter than the sound	The play is cut at the Lifetime.
Above 0, longer than the sound, Looped off	The sound plays once. The rest of the Lifetime is silent.
Above 0, Looped on	The sound repeats until the Lifetime ends.

With Lifetime 0, the Speed at the start sets how long the play lasts. A sound 2.4 seconds long at Speed 2 lasts about 1.2 seconds. A Volume graph from 0.5 to 0 fades over those 1.2 seconds.

With Looped on, enter a Lifetime above 0.

Start At

Playing starts that many seconds into the sound.

Roll-off

Roll-off Min and Roll-off Max apply to a play that has a position. A play with 2D (local) on ignores them.

Events

The Events section works as on any emitter. See Events. A Sound emitter fired by an event fires in place. An event cannot move it to another position.

Advanced

Row	Kind	Starts at	What it does
Anim. Steps	Number	100	How many times the Volume and Speed graphs are read over one Lifetime.
Emit Into	Instance, picked with *	None	Where plays are placed. See Where the sound plays from.

Advanced describes these rows in full.

With the tools

Tool	Effect on a Sound emitter
Size	Multiplies Roll-off Min and Roll-off Max.
Time	Multiplies Rate and divides Lifetime.

Size and Time describes both tools.

Limits

• No Animate mode. The Mode and Loop rows are not present.
• No Linger row and no Pool row. Every play is removed when it ends.
• No Motion rows and no Link. To move a sound, nest it in an emitter that moves.
• Switching Enabled off stops new plays. Plays already started run to their end. The Stop Emits shortcut ends them at once. See Shortcuts.
• Each play counts as one particle toward the Particle Cap while it sounds.