[UE4] AkReverbVolume priority is not working

Question

It seems that no matter what, overlapping AkReverbVolumes will always blend as if they were the same priority. If I create one volume with priority 1, and an overlapping one with priority 5, they will both be blended 50/50 in the overlapping area.  Is anyone else having this problem? Is there a way around this?

This is mainly an issue as  I need to have a large volume enclosing the entire level (for an outdoors reverb profile) and other higher priority ones for indoors which will override the outdoors volume.

Answer 1

This is by design. The Wwise SoundEngine supports up to 4 Game-defined auxiliary sends. What happens is that the integration builds a list of all ReverbVolumes at a position, sorts that list by priority, and then sends the first four to the SoundEngine. In your case, you only have two volumes at the same place, so both get set.

If you wish to change this behavior, look for AK_MAX_AUX_PER_OBJ in the code (there should be two places, and both lines are similar). The original line is:

for( int32 Idx = 0; Idx < CurrentAkReverbVolumes.Num() && Idx < AK_MAX_AUX_PER_OBJ; Idx++ )

 

change it to (for only one volume at a time) :

 

for( int32 Idx = 0; Idx < CurrentAkReverbVolumes.Num() && Idx < 1; Idx++ )

 

 

Comments

Thanks Benoit. That brings up another concern though- if we restrict the reverb volumes to 1 aux channel, will we also be hurting the fade in/out behaviour of going from one volume to another? Thanks.

---

You're right. The way the code is built at the moment, this could potentially yield weird results with fades. You would need to change the UAkComponent::ApplyAkReverbVolumeList function to "accept" only one new reverb volume when a new one is found, and keep the existing ones that are in the process of fading.

---

C'est beau, merci! I will see if the programmers can work something out- if not I can always create exterior volumes that specifically cover exterior areas instead of one big one that covers the entire level.

---

Hi, just wanted to give a follow up on this issue. My programmer ended up cleverly modifying the code to keep the 4 aux buses, AND allow up to 4 to be used simultaneously. The code just checks to see if the reverb volume name contains the the "exterior". If one exists, all others will fade out and the exterior volume overrides. If not, it's business as usual.

Cheers!