When enabled, audio acoustic simulation appears to severely degrade the performance of AudioEmitters in my game, cutting my framerates by three quarters, from 120 to 30.
I have only 7 audio emitters.
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Hey @ThoughtSpinnr – I opened the place and am able to reproduce the lag. Will investigate
so i WASNT going insane. i was looking through the acoustic simulation post and didnt see anything about lag
Thanks a bunch! This was a very confusing issue for me to narrow down – for weeks I’d been thinking it was the fault of a private beta I’ve been helping test.
No this is definitely our bug
There’s a fix-candidate in-review that should go out in a couple weeks; in my testing, this is the before & after comparison in your placefile:
This looks much better, thank you! What ended up being the culprit here?
Sort of two root causes
Acoustic simulation uses physics queries under the hood; the most common one checks how dense the parts within a region are. Since this placefile uses MeshParts that are fairly close together, that ended up being slow – both because it has to scan more parts, and the parts themselves aren’t simple convex shapes. So one fix is to make that density-in-region query faster (but more approximate). This could also be made faster by using simpler Parts or toggling some of the meshes to AudioCanCollide = false
The other thing is that we’re doing these queries asynchronously on background threads, but updating the physics data structures on a foreground thread. Those background threads need to coordinate with the foreground thread so that there isn’t a data-race/crash. That coordination mechanism was giving equal priority to all threads – but in this case we need the foreground thread to “always win”, because it impacts the framerate
Ah, gotcha. Thanks very much for the explanation! 
I suppose this means that in extreme cases like mine, occluded audio may take a little longer to update in order to never harm the framerate?
Yeah; the framerate will be fine, but the acoustics might be a few frames behind schedule
