Efficient Propagation and Remapping of Sound Through a Geometric Approach in Virtual Environments and Terrains

In this paper, we propose an efficient sound propagation and remapping technique based on geometry to enhance immersive sound effects in virtual environments, and suggest a method to interactively represent sound by considering the altitude and slope of the terrain. The proposed technique can represent real-time patterns of sound such as waves and flows of sound, as well as diffraction that occur in a physical environment. Our approach involves identifying the position of obstacles from the sound source and calculating the new position of sound that has been refracted or diffracted due to the obstacles. Using a ray-tracing technique, we determine whether there is a collision between obstacles and sound, and calculate the reflected and refracted vectors due to the collision to predict the magnitude of sound that agents beyond the obstacles would hear. In this process, the number of reflected and refracted rays affects the magnitude of sound, allowing us to model sound attenuation based on the distance to the obstacle and the material of the obstacle. In this process, we control the magnitude of sound based on the altitude difference from the sound source and the gradient difference depending on the shape of the surrounding terrain. As a result, we efficiently and quickly represented diffraction patterns expressed in a physically-based approach, and demonstrated that the magnitude of sound diffuses naturally according to the deformed diffraction pattern as the obstacles move and rotate. Furthermore, we realistically represented the sound heard by the audience in terrains with altitude differences, and demonstrated that the magnitude of sound varies depending on the terrain.