An image representing the cost to traverse each pixel. Masked pixels can't be traversed.
A single-band image representing the sources. A pixel value different from 0 defines a source pixel.
Maximum distance for computation, in meters.
Boolean, default: true
If true, geodetic distance along the curved surface is used, assuming a spherical Earth of radius 6378137.0. If false, euclidean distance in the 2D plane of the map projection is used (faster, but less accurate).