A ray tracing simulation of sound diffraction based on analytic secondary source model

In this paper, we propose a novel method to estimate impulse response of sound diffraction based on ray tracing. This method is a Monte Carlo solution of multiple integration in analytic secondary source model of edge-diffraction, in which sample values of the integrand are calculated by ray tracing process. Similarity between our method and general ray tracing makes it possible to utilize various approaches developed for ray tracing. In our implementation, a ray tracing engine OptiX is employed, which exhibits good acceleration on a graphics processor. For more efficiency, we use importance sampling where insignificant diffraction paths are eliminated stochastically and thus reducing the number of samples. Based on these approaches, the proposed method achieves a processing performance of about 24M samples/sec for the simulation of first-order diffraction, which demonstrates the applicability to interactive simulation.