Spatial audio

USD can author sound as part of a scene through UsdMediaSpatialAudio prims, each naming an audio file, a position in the scene, and a start time on the stage's timeline. Solidly plays them. No other format Solidly reads carries audio.

Playback

When a stage carries audio, the animation player gains a mute control. Audio follows the animation transport: it starts and stops with playback, it follows a seek on the timeline, and it respects the playback speed. Sources are positioned in the scene, so what you hear follows the camera as it moves.

Whether audio starts muted is remembered per model along with the rest of its playback state, so a stage muted once stays muted when you switch away and back.

Inspecting audio sources

The Resources tab has a Spatial Audio section for a stage that has any. Each entry names the prim, the audio file it refers to, and the timing the prim declares. A source whose file could not be resolved is listed without being playable.