Download Dynamic Grids for Finite-Difference Schemes in Musical Instrument Simulations For physical modelling sound synthesis, many techniques are available; time-stepping methods (e.g., finite-difference time-domain
(FDTD) methods) have an advantage of flexibility and generality
in terms of the type of systems they can model. These methods do,
however, lack the capability of easily handling smooth parameter
changes while retaining optimal simulation quality and stability,
something other techniques are better suited for. In this paper,
we propose an efficient method to smoothly add and remove grid
points from a FDTD simulation under sub-audio rate parameter
variations. This allows for dynamic parameter changes in physical models of musical instruments. An instrument such as the
trombone can now be modelled using FDTD methods, as well as
physically impossible instruments where parameters such as e.g.
material density or its geometry can be made time-varying. Results show that the method does not produce (visible) artifacts and
stability analysis is ongoing.
Download A Physical Model of the Trombone Using Dynamic Grids for Finite-Difference Schemes In this paper, a complete simulation of a trombone using finitedifference time-domain (FDTD) methods is proposed. In particular, we propose the use of a novel method to dynamically vary the
number of grid points associated to the FDTD method, to simulate
the fact that the physical dimension of the trombone’s resonator
dynamically varies over time. We describe the different elements
of the model and present the results of a real-time simulation.
Download Real-Time Implementation of a Friction Drum Inspired Instrument Using Finite Difference Schemes Physical modelling sound synthesis is a powerful method for constructing virtual instruments aiming to mimic the sound of realworld counterparts, while allowing for the possibility of engaging
with these instruments in ways which may be impossible in person.
Such a case is explored in this paper: particularly the simulation
of a friction drum inspired instrument. It is an instrument played
by causing the membrane of a drum head to vibrate via friction.
This involves rubbing the membrane via a stick or a cord attached
to its center, with the induced vibrations being transferred to the
air inside a sound box.
This paper describes the development of a real-time audio application which models such an instrument as a bowed membrane
connected to an acoustic tube. This is done by means of a numerical simulation using finite-difference time-domain (FDTD) methods in which the excitation, whose position is free to change in
real-time, is modelled by a highly non-linear elasto-plastic friction
model. Additionally, the virtual instrument allows for dynamically
modifying physical parameters of the model, thereby allowing the
user to generate new and interesting sounds that go beyond a realworld friction drum.