I have some LIDAR data files where the ocean is at height 0, I intend to use them in a game engine and have dropped the sea surface to use a water material. However this left every island with vertical cliffs below the sea surface, I'm trying to use the Mound tool "upside down" to generate a slope down to the sea floor from each of them, but I'm having some odd effects (over the surface everything flattened to the max height, below the surface my sea floor slopes until 1000m rather than 100m)
Has anyone done anything similar?