Radiation transfer and scene representation LiES Forest Light Environmental Simulatior (FLiES) is a Monte Carlo-based 3D radiative transfer model.
BRF was sampled at every scattering events and determined local estimation method, which enable to calculate the BRF at exact point of direction.
Kobayashi, H., and H. Iwabuchi,
A coupled 1-D atmosphere and 3-D canopy radiative transfer model for canopy reflectance, light environment, and photosynthesis simulation in a heterogeneous landscape,
Remote Sensing Environment, 112, 173-185.