Hello,

I’m writing to report two critical issues encountered in SDK v74 when using FMOD 2.03.06 with Unreal Engine 5.5.4 (modified to compile via MetaXRAudio.Build.cs adjustments, as official UE 5.5 support is pending in v76).

Issue 1: Occlusion Regression in v74

Description:
Occlusion behavior degrades in v74 compared to v72. Sound incorrectly interacts with geometry (e.g., improper attenuation when obstacles appear), despite identical scene configurations. Reverting to v72 libraries restores expected behavior. Here's video comparison demonstrating occlusion behavior differences between v74 and v72:

v74 FMOD libs: https://vimeo.com/1076316873/88744e8637

v72 FMOD libs: https://vimeo.com/1076318611/c5b7067c2b

Issue 2: Coordinate System Mismatch in Acoustic Ray Tracing

Description:
Acoustic probes generate at incorrect positions due to a coordinate system mismatch between ovrAudio and Unreal Engine. Probes spawn on cube side faces instead of top faces (see attached screenshot).

The coordinate system issue can be temporarily resolved by modifying MetaXRAcousticMap.cpp:

Parameters.gravityVector[0] = (float)AcousticMapComponent->GravityVector.X;
Parameters.gravityVector[1] = (float)AcousticMapComponent->GravityVector.Z; // Modified from Y
Parameters.gravityVector[2] = (float)AcousticMapComponent->GravityVector.Y; // Modified from Z

Thank you for your attention to this matter. Please let me know if additional details or test projects would assist in debugging.