This node can be added to pairs. When the Radiation discretization method is Discrete ordinates method, it prescribes that the radiative intensity field I is continuous across the pair. When the Radiation discretization method is P1 approximation, it prescribes that the incident radiation field G is continuous across the pair. Continuity is only suitable for pairs where the boundaries match.

Choose the pair on which to apply this condition. A pair has to be created first. See Identity and Contact Pairs in the COMSOL Multiphysics Reference Manual for more details.

Physics Tab with interface as Radiation in Participating Media or Radiation in Absorbing-Scattering Media selected:
Pairs>interface>Continuity