Improved adjustable boundary condition for the 3-D digital waveguide mesh

The digital waveguide (DWG) mesh is a method for simulating wave propagation in multiple dimensions. In three-dimensional form it can be used for modeling room acoustics or resonating bodies of musical instruments, for example. Until now boundary conditions in the three-dimensional DWG mesh have been implemented using methods originating from the updating functions of a one-dimensional digital waveguide. A new boundary structure, which better takes into account the 3-D mesh topology, is now introduced. With this new method, the reflection magnitude is shown to match the desired value over a much wider range of reflection coefficient values than with the earlier method.