The spatial distribution of solar radiation in a plant canopy influences eco-physiological functions and gives a measure of the light-interception efficiency of stand architecture. A simulation model of the three dimensional (3D) distribution of direct solar radiation in a real maize canopy was developed from precise measurements of 3D canopy structure. The plant organ surfaces in a real canopy were subdivided into multiple facets based on 3D coordinate data obtained by digitizing in the field. The model wa...