Efficient shadowing determination at grazing incidence, for mesh‐based physical optics scattering analysis

Shadowing determination is a crucial step in methods based on the physical optics approximation, which are widely used for electromagnetic scattering analysis of electrically large, conducting bodies. When the surface current is represented by basis functions on a mesh of triangle elements, this involves determining for each mesh edge and/or elemental face whether it is visible to the source or obscured by another mesh element. A field‐of‐view buffer‐based shadowing determination algorithm for plane wave illumination of triangle‐element meshes is presented, with special provision to maintain efficiency in case of grazing incidence. For homogeneous meshes, the computational costs in runtime and memory are both directly proportional to the number of mesh elements.