Coupled Semitransparent boundary for fvDOM
 

I am trying to develop a coupled Semitransparent boundary for fvDOM. The turbulentTemperatureRadCoupledMixedFvPatchScalarFi eld is quite straight forward, which coupled the, Qr, heat flux for radiation between the solid and fluid. For semitransparent boundary, I need to access the DOM object in nearby mesh, and then map the each ray on the other side for the every ray on this side. For me, that sounds quite wasteful. And also the light diffusion part on surface also doesn't need to be calculated for each ray.
The only alternative I can think of is to set all the ray boundary to fixValue and do all the calculation update the boundary in the solver.