llPlaySound or llTriggerSound

[Xxaxx Constantine]

Can someone please give me a clue on when one should use llPlaySound versus llTriggerSound?

I suppose the issue comes down to not really understanding the difference between an attached sound and unattached sound.

Would this mean the sound follows the object -- if the object is moving.

But will that matter if the object doesn't move?

 

[PeterCanessa Oh]

Exactly, and yes - if the object isn't moving and isn't a HUD there's no practical difference between the two functions.

ETA: Doh!  Rather important typo *blush*

[Rolig Loon]

Nope.  Not a bit.

Suppose you make a train.  You have a horn in the train that should play as it approaches a crossing, so you use llPlaySound.  That way, the horn's sound travels with the moving train, as you'd expect it to in the real world.  Suppose that you also have a crossing signal that should ring a bell when the train approaches.  You could put the bell sound and the actuating script in the crossing signal, which is what I would normally do.  You could put the script in the train instead, though.  If so, you'd want to use llTriggerSound when the train reaches a specific location.  That way, the bell sound will start at that spot and will still be playing there as the train moves ahead.

And yes, if the train isn't moving at all when the script actuates a sound, it won't matter which function you use.

[Xxaxx Constantine]

Thank you both for the answers.

Follow up question though.

I am wondering based on your answers if there are special considerations when using sound from a hud.

 

[Rolig Loon]

I can't think of any.

[PeterCanessa Oh]

The rather obvious one is that only the person wearing the HUD will hear it if is an attached sound.  If you want anyone else to hear it you HAVE to use an unattached one.

Together this means that it is not possible for a HUD to publicly play sounds as the wearer moves around.

[Xxaxx Constantine]

Very helpful information.

Much appreciated.

[Fenix Eldritch]

I believe it's also worth mentioning that llPlaySound only supports one sound at a time. So if your script makes a second llPlaySound call before the first one finished playing, it will cut off the first as it starts the second. Unnatached sounds will not experience this can can be layered.

Including llSetSoundQueueing(TRUE) would cause llPlaySound calls to let the previous one finish before starting the next.