Multibounce

Multibounce refers to the phenomenon in which a wave, particle, or signal experiences more than one sequential reflection between surfaces before being absorbed, transmitted, or detected. Each reflection can change direction, attenuate amplitude, and introduce phase shifts, so the cumulative effect depends on geometry, material properties, and the properties of the incident wave.

It is a key consideration in acoustics for room reverberation, in optics for optical resonators and cavity quantum electrodynamics, in wireless communications for multipath propagation, and in computer graphics for global illumination. The term contrasts with single-bounce or direct reflections, although in practice many applications must account for a continuum of bounce orders from zero to many.

Mathematically, multibounce light or sound paths are modeled as a sum over bounce orders. Each order multiplies by a reflection coefficient and a phase factor determined by the path length. In rendering, path tracing and radiosity approaches aim to approximate this series to simulate realistic lighting. In acoustics, impulse response includes contributions from reflections of different orders, shaping reverberation time and intelligibility.

Limitations include computational cost and diminishing returns as higher-order bounces contribute less energy. Accurate modelling requires knowledge of surface properties, geometry, and the spectral content of the source. In practice, a finite number of bounces is simulated.

See also: reflection, multipath, reverberation, global illumination, ray tracing, scattering.