NESTED RADIOSITY FOR PLANT CANOPIES

We present nested radiosity, a new approach for simulating the distrib ution of natural light within plant canopies. The geometric descriptio n of a canopy requires many polygons, and its spatial coherence is low er than that of an architectural scene. We compute the total irradianc e of polygons by summing the irradiance due to close polygons (calcula ted with the radiosity equation) and the irradiance brought by distant polygons (approximated by the radiative transfer equation). The reduc ed number of form factors can be stored in a sparse matrix. Then sever al radiative conditions can be quickly simulated. The simulation resul ts for this model are compared with those produced by a Monte Carlo ra y tracing.