Spatialization, lifetime, and concurrency

MetaSound generates a source; standard Unreal audio systems still own attenuation, spatialization, occlusion, classes, submixes, concurrency, priority, and virtualization.

Spatial contract

• Use attenuation assets/settings for distance curves, shape, spatialization, air absorption, occlusion, and focus according to the game.
• Add UE.Attenuation when graph behavior needs listener distance.
• Add UE.Spatialization when graph behavior needs azimuth/elevation.
• Test listener motion, split screen if supported, occlusion transitions, and teleport/discontinuity.

Do not synthesize manual left/right panning as a substitute for the engine spatializer when true 3D audio is required.

Lifetime

• Finite Source: terminal trigger -> On Finished; component auto-destroy/pool policy verified.
• Indefinite Source: no one-shot interface; external owner controls release/stop.
• Looping Wave Player: graph/source must still define when the overall sound ends.
• Virtualized source: define whether time advances silently or restarts when audible.

Concurrency

Group semantically interchangeable voices and choose maximum count/resolution rule by information priority. Test bursts, nearby identical sources, quiet-loop accumulation, and modulation interaction. Concurrency voice stealing is a mix/design decision: never allow a low-value decorative sound to steal a critical warning merely because it started later.