In this tutorial there will be used two different types of radiation models: P1 model and FvDOM model

P1 is the simplest case of the more general P-N model, which is based on the expansion of the radiation intensity into an orthogonal series of spherical harmonics

Acronym FvDOM stands for Finite Volume Discrete Ordinates Method. FvDOM radiation model solves the radiative transfer equation (RTE) for a finite number of discrete solid angles, each associated with a vector direction

In both radiation models there are used constant absorbtion and emission coefficients specified in constant/radiationProperties

None of these two radiation models include scattering (deviation from a straight trajectory).