Bachelor's thesis in media- and sonic communicationTitle: Sound occlusion for virtual 3D environments
Subtitle: A solution for real-time filtered sound propagation for arbitrary and non-convex geometry
Submission date: 22-12-2016
Supervisor: Niels B÷ttcher
University College Syddanmark: Sonic College, class MS2013
The effects of sound occlusion and sound obstruction are investigated and modelled, to propose a solution that allows this effect in virtual 3D environments (such as games) with arbitrary geometry, together with implementing spatialisation and localisation. The solution is specifically designed to handle completely non-convex geometry, since the emitted audio has encoded localisation cues, modelled after acoustic physics, so the system can be used for spatial navigation and attention.
The proposed solution uses theory from heat radiation physics to reduce geometry to surfaces to calculate paths and emissivity. Audio effects and filters are used to simulate sound moving through spaces with delays and Doppler-effects, as well as the filtering of surfaces themselves, whether the sound moves through or reflects off. Head-related transfer functions (HRTF) that describe how humans are able to localize sounds are derived from sound localisation theory and binaural impulse responses to implement a procedural down mixer, that spatialises mono sounds as though they come from a specific direction.
The solution is measured, discussed and compared to relevant work, as well as implemented in a current 3D games engine today, to present the system using some situations and scenes, showing how it can deal with discussed cases, such as completely non-convex geometry.