Overview

Sounds can be attached to particle effects or their sub-effects, as follows:

• Select a particle effect or sub-effect.
• Browse and add a sound event. The sound event will start when the effect or sub-effect starts. If you wish to delay the start of the sound, attach it to a sub-effect and use spawn delay to delay the start time.
• Sounds will stop when the particle effect stops. It is recommended that a fade-out time is set in the sound event properties in the FMod Designer project to enable a smooth stopping of the sound.

For an advanced handling of sound over the lifetime of the particle effect, perform the following steps:

• Create a parameter called particlefx in a sound event. This parameter must be present or an error will occur.
• Add that sound event to a particle effect.
• Set the Sound FXParam label to 1. This defines the maximum value sent to the particlefx parameter of the sound event.
• Draw a curve in the Var Emitter Life graph. The x-axis represents time, whereas the y-axis represents the value sent to the particlefx parameter in the sound event.

• The curve will gradually move the value of particlefx from 0.0 to 1.0, over the life of the particle effect.
• A typical use may be to have a volume curve on the particlefx parameter in the sound event, which reduces the volume of the sound as the value of the parameter moves from 0.0 to 1.0.
• Optionally, select a value for the Random Var label. A random amount from 0.0 to the maximum random value will be subtracted from the parameter each time the particle effect is played. This causes the value of the parameter to be lowered by a random amount. For example, if the value of Sound FXParam is 1.0 (as recommended) and Random Var is set to 0.2, then, each time the effect is played, the maximum value of FXParam would be set anywhere between 1.0 to 0.8.

Sound Control Time

"Sound Control Time" offers three different options: "EmitterLifeTime" (default), "EmitterExtendedLifeTime" and "EmitterPulsePeriod".

These 3 options control over what time the "particlefx" parameter is updated by the emitter.

This applies to looping and one shot sounds. Looping sounds will be stopped at the end of EmitterLifeTime and EmitterExtendedLifeTime but not EmitterPulsePeriod. Do notice that oneshot sounds won't be stopped.