Materials are defined by the absorption coefficient from 63 to 8000 Hz and a frequency dependent scattering coefficient. A surface or a double sided wall can also be given a transparency coefficient or a reduction index allowing transmission between rooms to be calculated.
Absorption data are from an extendable library of materials. The surface list is linked to a 3D display showing the selected surface. In larger room models the use of layers can facilitate the material assignment.
User-friendly material list interface for assignment of materials to surfaces.
In order to calculate the influence of scattering from surface roughness and from edge diffraction, the Reflection Based Scattering method has been developed in Odeon. Diffraction depends on the area of the surface and distance from the source. See the two examples above; near source and remote source.
The automatic detection and calculation of diffraction around one or two edges predicts the attenuation behind screens and barriers.