  We introduce bidirectional edge diffraction response function (BEDRF), a new
approach to model wave diffraction around edges with path tracing. The
diffraction part of the wave is expressed as an integration on path space, and
the wave-edge interaction is expressed using only the localized information
around points on the edge similar to a bidirectional scattering distribution
function (BSDF) for visual rendering. For an infinite single wedge, our model
generates the same result as the analytic solution. Our approach can be easily
integrated into interactive geometric sound propagation algorithms that use
path tracing to compute specular and diffuse reflections. Our resulting
propagation algorithm can approximate complex wave propagation phenomena
involving high-order diffraction, and is able to handle dynamic, deformable
objects and moving sources and listeners. We highlight the performance of our
approach in different scenarios to generate smooth auralization.
