This function is made to be used in rasterize_terrain or normalize_height . It implements an algorithm for spatial interpolation. Spatial interpolation is based on a Delaunay triangulation, which performs a linear interpolation within each triangle. There are usually a few points outside the convex hull, determined by the ground points at the very edge of the dataset, that cannot be interpolated with a triangulation. Extrapolation can be performed with another algorithm.
tin(..., extrapolate = knnidw(3,1,50))
Arguments
...: unused
extrapolate: There are usually a few points outside the convex hull, determined by the ground points at the very edge of the dataset, that cannot be interpolated with a triangulation. Extrapolation is done using knnidw by default.