You have (at this moment in time) four sections to aid in generating your HeightMap/SplatMaps.
Terrain Dimensions: Size is 1:1 ratio, so x512 = 512x512, x1024 = 1024x1024, etc.
Max Height: Relative scaling is applied after the map height and min height are applied to the HeightMap.
Terrain Seed: Provides you with an integer input to aid in noise generation for the HeightMap.
Smoothing Passes: helps to smooth the terrain, each pass is compounded to the next pass.
Once you have the desired settings, hit the "Generate" button, this will generate a black/white noise heightmap image, and then use the same heightmap to generate a splatmap with color changes every 0.01 float in height for your terrain textures. If you like the generated images, hit the "Export" button, this will export the RAW data to your projects asset folder, where you can then apply the HeightMap to your terrain component.
