A canopy reflectance model, the Botanical Plant Modelling System (BPMS), is described. The model is capable of ingesting information on plant structure from a variety of sources, such as stereo photogrammetric measurements, dynamic models and direct manual measurements, and creating three-dimensional (3D) models of the structure of individual plants in a canopy and/or underlying soil/topography. The canopy radiation regime is simulated from the definition of the illumination conditions, camera imaging properties and plant and soil radiometric attributes using Monte Carlo ray tracing. The model is aimed at simulating the canopy shortwave radiometric regime and its component parts to allow the study of the effect of plant geometry and other f...