积分形式的辐射传输方程Let L L L be the streaming-collision operator, and S S S is scattering operator, we have L I = Ω ⋅ ∇ I ( r , Ω ) + σ ( r , Ω ) I ( r , Ω ) LI=\Omega\cdot\nabla I(r,\Omega)+\sigma(r,\Omega)I(r,\Omega) LI=Ω⋅∇I(r,Ω)+σ(r,Ω)I(r,Ω) and S I = ∫ 4 π σ s ( r , Ω ′