Fast Edge-Diffraction for Sound Propagation in Complex Virtual Environments

Micah Taylor, Anish Chandak, Zhimin Ren Christian Lauterbach, and Dinesh Manocha

Dynamic Diffraction Effects: As the door closes, the frequency spectrum is appropriately attenuated. Our system can render propagation in scenes with moving sources, receivers, and geometry.

Fast Edge-Diffraction for Sound Propagation in Complex Virtual Environments
EAA Symposium on Auralization 2009
We present an algorithm for fast computation of diffraction paths for geometric-acoustics in complex environments based on the UTD formulation. Our method extends ray-frustum tracing to efficiently compute paths in the shadow region caused by long diffracting edges. Our approach can handle general scenes with moving sources, receivers, and dynamic objects. We evaluate the accuracy through comparisons with physically validated geometric simulations. In practice, our edge diffraction algorithm can perform sound propagation at nearly interactive rates in dynamic scenarios on a multi-core PC.

Our system can efficiently perform geometric audio propagation in complex scenes with diffraction effect. The following videos show a sample of our system in action.

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Outdoor scene with dynamic geometry. Diffraction effects allow a smooth transition as the direct path between source and receiver is obstructed.

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In this indoor sequence, we compare our system with a more accurate numerical simulation. While the numerical simulation is more accurate, our system is much faster.

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First order reflection and diffraction with a moving source in a bedroom.
Related Links
Acoustic research at GAMMA
Sound Propagation using Frustum Tracing