Shader-based Physical Modelling for the Design of Massive Digital Musical Instruments

Zappi, Victor and Allen, Andrew and Fels, Sidney

Proceedings of the International Conference on New Interfaces for Musical Expression

Physical modelling is a sophisticated synthesis technique, often used in the design of Digital Musical Instruments (DMIs). Some of the most precise physical simulations of sound propagation are based on Finite-Difference Time-Domain (FDTD) methods, which are stable, highly parameterizable but characterized by an extremely heavy computational load. This drawback hinders the spread of FDTD from the domain of off-line simulations to the one of DMIs. With this paper, we present a novel approach to real-time physical modelling synthesis, which implements a 2D FDTD solver as a shader program running on the GPU directly within the graphics pipeline. The result is a system capable of running fully interactive, massively sized simulation domains, suitable for novel DMI design. With the help of diagrams and code snippets, we provide the implementation details of a first interactive application, a drum head simulator whose source code is available online. Finally, we evaluate the proposed system, showing how this new approach can work as a valuable alternative to classic GPGPU modelling.