Extended scattering delay networks incorporating arbitrarily shaped rooms and edge diffraction

Pekçetin, Serkan
In order to achieve immersion in computer games, room acoustics models are often employed. Due to highly computational cost involved in full-scale room simulation, artificial reverberators are commonly used. Scattering Delay Network is such a reverberator that can run at interactive rates. The reverberator relies on geometrical acoustics to render first-order reflections correctly while it offers a convincing approximation in higher order reflections. The original model was exclusively proposed for shoebox type of room settings. The aim of this study is to extend the reverberator by allowing it to work in arbitrarily shaped rooms. Besides, enhanced perception of the virtual environment is proposed by approximating first-order edge diffraction model. The extended algorithm uses visibility checks by ray casting in order to determine which surfaces have an energy transaction. Edge diffraction component of the room impulse response is then approximated by using a best-fit approach. Decay parameter for the inverse exponential function is obtained by using ternary search. Scope of the original algorithm is extended at the expense of minimal computational complexity.