It’s hasn't any effect to use "SetVolume" to set the sound

I intend to set the volume of the sound use the interface “SetVolume”,but it seems doesn’t matter,so how can I set the volume?And how can I make the sound fade in and fade out?(I use the latest FMOD Studio)

EventInstance::SetVolume is set by percentage of the default volume set in FMOD Studio. (eg. 0 = 0% or -80db, 0.5 = 50% or -40db, 1 = 100% or 0db)

As for fading, this depends on how and when you want it to fade.
Normal to fade in when you start it and out when it ends you would add modulation to the volume of the event.
Read more about that here: