Interactive Edge-Diffraction for Sound Propagation in Complex Virtual Environments

We present an algorithm for interactive computation of diffraction paths for geometric-acoustics in complex environments. Our method extends ray-frustum tracing [Lauterbach et al. 2007] to efficiently compute volumetric regions of the sound field caused by long diffracting edges. We compute accurate diffraction paths from each source to the listener and based on the Uniform Theory of Diffraction, attenuate the input audio. The overall approach is general, can handle dynamic scenes, and can be used to compute diffraction and specular reflection paths with relatively little aliasing. We evaluate the accuracy through comparisons with physically validated geometric simulations. In practice, our edge diffraction algorithm can perform sound propagation at interactive rates in dynamic scenarios on a multi-core PC.