SCATMECH > Classes and Functions > Property Models > Reflectance

Abstract class Reflectance

The class Reflectance is an abstract class for describing the diffuse reflectance of a substrate. Reflectance is used by Lambertian_BRDF_Model and Diffuse_Subsurface_BRDF_Model, where beforehand the reflectance was described by a Table. Three different instantiable classes inherit the properties of Reflectance:

Table_Reflectance -- Reflectance given by a Table.
Equation_Reflectance -- Reflectance given by an expression (using the class Evaluator).
Kubelka_Munk_Reflectance -- Reflectance given by the Kubelka-Munk model for diffuse scattering.

Instantiable Models and Their Parameters:

Parameter	Data Type	Description	Default
Table_Reflectance: A simple reflectance whose wavelength dependence is obtained from a table of values.
table	Table	The reflectance, given either as the name of a file containing the reflectance as a function of wavelength, or as a constant value.	1
Equation_Reflectance: A reflectance given by an equation as a function of wavelength (given by x in the equation).
expression	string	An expression (given by a function of the wavelength, x) for the reflectance.	1
Kubelka_Munk_Reflectance: A reflectance given by the theory of Kubelka and Munk [Z. Tech. Phys. 12, 593 (1931)] for a paint coating having specific scattering and absorption coefficients and thickness and substrate reflectance.
thickness	double	The thickness of the coating [µm].	1
absorbance	string	An expression for the absorption coefficient as a function of wavelength [1/µm]. This expression can be a simple expression, or it can be the sum of multiple tables, e.g., `&redpigment(x)+&bluepigment(x)`.	1
scattering	string	An expression for the scattering coefficient as a function of wavelength [1/µm]. This expression can be a simple expression, or it can be the sum of multiple tables, e.g., `&whitepigment(x)+&yellowpigment(x)`.	1
substrate	Reflectance_Ptr	The reflectance of the underlying material	Table_Reflectance

Include file:

#include "reflectance.h"

Source code:

reflectance.cpp

Definition of public elements:

class Reflectance : public Model {
    virtual double Get_Reflectance(double lambda) = 0;
};

typedef Model_Ptr<Reflectance> Reflectance_Ptr;

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double Get_Reflectance(double lambda)

This function evaluates the reflectance at wavelength lambda.

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Current SCATMECH version: 6.00 (February 2008)
This page first online: Version 6.00 (February 2008)
This page last modified: Version 6.00 (February 2008)