Acoustic Wave Modeling Using 2D FDTD: Applications in Unreal Engine For Dynamic Sound Rendering

TL;DR

This paper introduces a 2D FDTD-based sound propagation model integrated into Unreal Engine, capturing complex wave phenomena for realistic dynamic sound rendering in virtual environments.

Contribution

It presents a novel 2D FDTD framework for acoustic simulation in Unreal Engine, effectively modeling wave phenomena like diffraction and interference for immersive audio experiences.

Findings

Benchmark results match analytical expectations

Impulse responses retain spatial directionality

Framework enables dynamic sound rendering in virtual environments

Abstract

Accurate sound propagation simulation is essential for delivering immersive experiences in virtual applications, yet industry methods for acoustic modeling often do not account for the full breadth of acoustic wave phenomena. This paper proposes a novel two-dimensional (2D) finite-difference time-domain (FDTD) framework that simulates sound propagation as a wave-based model in Unreal Engine, with an emphasis on capturing lower frequency wave phenomena, embedding occlusion, diffraction, reflection and interference in generated impulse responses. The process begins by discretizing the scene geometry into a 2D grid via a top-down projection from which obstacle masks and boundary conditions are derived. A Python-based FDTD solver injects a sine sweep at a source position, and virtual quadraphonic microphone arrays record pressure field responses at pre-defined listener positions. De-convolution of the pressure responses yields multi-channel impulse responses that retain spatial directionality which are then integrated into Unreal Engine's audio pipeline for dynamic playback. Benchmark tests confirm agreement with analytical expectations, and the paper outlines hybrid extensions aimed at commercial viability.