- Remove silence padding accumulation bug: QueueAudio'd silence was
accumulating in USoundWaveProcedural's internal buffer during TTS gaps,
delaying real audio by ~800ms. USoundWaveProcedural with
INDEFINITELY_LOOPING_DURATION generates silence internally instead.
- Fix pre-buffer bypass: guard OnProceduralUnderflow with bPreBuffering
check — the audio component never stops (INDEFINITELY_LOOPING_DURATION)
so it was draining AudioQueue during pre-buffering, defeating it entirely.
- Audio pre-buffer default 2000ms (max 4000ms) to absorb ElevenLabs
server-side TTS inter-chunk gaps (~2s between chunks confirmed).
- Add diagnostic timestamps [T+Xs] in HandleAudioReceived and
AudioQueue DRY/recovered logs for debugging audio pipeline timing.
- Fix lip sync not returning to neutral: add snap-to-zero (< 0.01)
in blendshape smoothing pass and clean up PreviousBlendshapes to
prevent asymptotic Lerp residuals keeping mouth slightly open.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
j.foucher
c2142f3e6b