What does llPreloadSound() really do?

So what does llPreloadSound() really do under the covers? I know it's supposed to preload a sound clip file -- but preload it *where*? Into all of the 'local' client AVs? Into the Sim cache? When happens when client AVs move into range? Or the object itself moves around?

What if I put the following code into a prim and wear the prim as an attachment

default
{
    state_entry()
    {
        llPreloadSound("mySound");
    }

    touch_start(integer total_number)
    {
        llPlaySound("mySound", 1.0);
    }
}

and then I walk up to you from 200m away -- does mySound automagically load into your AV's client? Or is llPreloadSound() pretty much worthless as coded here?

Jess

I believe - and this isn't solid experimentation backed by debug info, just from long use - I think llPreload just forces the sound to be downloaded to each client that would be in normal "hearing range" of the sound... basically, the same thing that happens when you use PlaySound, just without the actual playing of sound.

I'll buy that -- but when does this happen? In the code example above, would the preload only happen to clients that are around when state_entry() happens? Or -- does the attachment 'wear' the sound like it was a texture? Which, if I understand how SL works (hardly a sure bet) would cause approaching AV clients to preload the sound when they come into range?

Jess

I believe, again, it works exactly like llPlaySound in this regard; only those around when the function is executed load the sound.

That said, sounds carry quite a distance in SL, so I would not be at all surprised if it caused every agent in the sim to load the sound, but I'll have to experiment to try and see if this is true.