Interactive Sound Propagation with Bidirectional Path Tracing

摘要

We introduce Bidirectional Sound Transport (BST), a new algorithmrnthat simulates sound propagation by bidirectional path tracingrnusing multiple importance sampling. Our approach can handlernmultiple sources in large virtual environments with complex occlusion,rnand can produce plausible acoustic effects at an interactive raternon a desktop PC. We introduce a new metric based on the signalto-rnnoise ratio (SNR) of the energy response and use this metric tornevaluate the performance of ray-tracing-based acoustic simulationrnmethods. Our formulation exploits temporal coherence in termsrnof using the resulting sample distribution of the previous frame tornguide the sample distribution of the current one. We show that ourrnsample redistribution algorithm converges and better balances betweenrnearly and late reflections. We evaluate our approach on differentrnbenchmarks and demonstrate significant speedup over priorrngeometric acoustic algorithms.