Precomputed Wave Simulation for Real-Time Sound Propagation of Dynamic Sources in Complex Scenes
Precomputed Wave Simulation for Real-Time Sound Propagation of Dynamic Sources in Complex Scenes
Nikunj Raghuvanshi, John Snyder, Ravish Mehra, Ming Lin, Naga Govindaraju
To appear in ACM Transactions on Graphics (SIGGRAPH 2010), 29(3), July 2010.

Our method performs real-time auralization of sounds from dynamic agents, objects and the player interacting in the scene, while accounting for perceptually important effects such as diffraction low-pass filtering and reverberation. Train station and citadel scenes are from Valve’s SourceTM game engine SDK.

Abstract:

We present a method for real-time sound propagation that captures all wave effects, including diffraction and reverberation, for multiple moving sources and a moving listener in a complex, static 3D scene. It performs an offline numerical simulation over the scene and then applies a novel technique to extract and compactly encode the perceptually salient information in the resulting acoustic responses. Each response is automatically broken into two phases: early reflections (ER) and late reverberation (LR), via a threshold on the temporal density of arriving wavefronts. The LR is simulated and stored in the frequency domain, once per room in the scene. The ER accounts for more detailed spatial variation, by recording a set of peak delays/amplitudes in the time domain and a residual frequency response sampled in octave frequency bands, at each source/receiver point pair in a 5D grid. An efficient run-time uses this precomputed representation to perform binaural sound rendering based on frequency-domain convolution. Our system demonstrates realistic, wave-based acoustic effects in real time, including diffraction low-passing behind obstructions, sound focusing, hollow reverberation in empty rooms, sound diffusion in fully-furnished rooms, and realistic late reverberation.

paper PDF supplementary PDF video (DivX,261MB)

Results:

Sound scattering and diffusion in the living room scene. The top row shows an empty room while the bottom row is fully-furnished. The left three columns show a 2D slice of the sound field generated by a Gaussian impulse emitted near the room’s center, while the right column shows the entire IR at a single receiver point placed at the source location. Red/blue represents positive/negative pressure in the sound field. Black areas represent solid geometry in the scene. Note the large difference in wave propagation in the two scenes because of scattering and diffraction. Refer to the video for comparative auralizations.
Other GAMMA sound projects
1) Numerical sound propagation -
             ARD
2) Geometric sound propagation -
             AD-frustum,
             frustum tracing,
             fast edge-diffraction,
             FastV,
             RESound
3) Sound synthesis -
             symphony,
             sliding sound,
             liquid sound