Predefined Functions for the Radiation in Participating Media Interface
When the Wavelength dependence of radiative properties is set to Solar and ambient or Multiple spectral bands, several predefined functions are available to obtain information about material properties. They can be used under the Results node to display the wavelength dependency of the material properties, and the values actually used in the computation for each band. These predefined functions are available for the following domain material properties:
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Absorption coefficient: kappaR
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Scattering coefficient: sigmaS
Predefined functions are also available for the following surface material properties:
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Emissivity: epsilon
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Diffuse reflectivity: rho_d
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Diffuse transmissivity: tau_d
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Specular transmissivity: tau_s
Several versions of the functions exist, averaged on the entire physics, averaged on a feature, or locally evaluated, and continuous, or piecewise constant. These functions start with an f and are followed by the symbol of the material property. Changing the scope and the suffix have different results:
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Physics averaged continuous functions are called with the scope of the physics and without suffix. They take one argument for the wavelength: rpm.fepsilon(lambda)
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Physics averaged piecewise constant functions are called with the scope of the physics and with the suffix “const”. They take one argument for the wavelength: rpm.fepsilon_const(lambda)
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Feature averaged continuous functions are called with the scope of the feature and without suffix. They take one argument for the wavelength: rpm.os1.fepsilon(lambda)
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Feature averaged piecewise constant functions are called with the scope of the feature and with the suffix “const”. They take one argument for the wavelength: rpm.os1.fepsilon_const(lambda)
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Locally evaluated continuous functions are called with the scope of the physics and with the suffix “at”. They take as many arguments as the dimension of the component to select the evaluation point, with the addition of the argument for the wavelength: rpm.fepsilon_at(x,y,z,lambda)
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Locally evaluated piecewise constant functions are called with the scope of the physics and with the suffix “atconst”. They take as many arguments as the dimension of the component to select the evaluation point, with the addition of the argument for the wavelength: rpm.fepsilon_atconst(x,y,z,lambda)
The handling of predefined functions for domain material properties is identical.
Feature averaged functions are available for the Participating Medium (Radiation in Participating Media Interface) domain feature, and for the following list of boundary features:
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Opaque Surface (Radiation in Participating Media and Radiation in Absorbing-Scattering Media Interfaces)
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Semitransparent Surface (Radiation in Participating Media and Radiation in Absorbing-Scattering Media Interfaces)
Physics averaged functions are averaged on all and only the features listed above.
Predefined plots are also available to add a built-in plot with the physics averaged functions for domain and surface material properties separately.