Real-world data websites such as Terrain.Party, Heightmapper, etc.In UE4 using Landscape Blueprint Brushes (experimental feature in 4.24+, heightmap gets created automatically).In UE4 using Sculpting Tools (heightmap gets created automatically as you sculpt).There are many different ways to create heightmaps. When exporting heightmaps for UE4, follow this format: Here is what it looks like after import in UE4: Here is what a heightmap texture will look like: Gray color that represents the middle of the heightmap is: All landscapes in UE4 rely on heightmap data to create the terrain.
Black color is low elevations or valleys and white color are high elevations or peaks. A heightmap is a grayscale texture that stores landscape height information.