Efficient determination of illumination over large 3D environments, including shadowing, is provided. Illumination, including shadows, is generated using a raster elevation map by a lighting solver. The lighting solver fetches the raster elevation map for an illumination area of interest at the paging rate and produces an illumination map that is applied to terrain and features by a 3D renderer. The lighting solver updates subsets of the illumination map as necessary to reflect changing illumination or movement of the visual area of interest.