A multi-level radiation transfer solution for 3D landscape

A multi-level radiation transfer method was proposed to simulate directional reflectance and images for 3D landscapes. This study emphasizes a unified framework to generate multi-level structures from leaf to landscape. Radiosity is adapted to improve calculation efficiency. The program was preliminarily evaluated and further applied to analyze how directional reflectance varies with fragmentation and terrain relief. Results indicate that grass dominated landscapes are more likely to be affected on directional reflectance feature by fragmented forest patches. Also, topographical relief can strongly enhance the hotspot effect and directional variations in the solar principal plane.