Remember there are two things we are discussing: 1. Height Fog kind of effect that simulates translucency, sub surface scattering and fake AO effect. 2. Second is simulating blend between two meshes (not terrain) using textures that start from lower party of mesh to edges or we can use Top down projection. You can see this other example of using height fog again and this time it even animates the blend color on top mesh for fun https://assetstore.unity.com/packages/vfx/shaders/height-fog-118960 *The image is very low res actual effect is very smooth. Here are some variations, now maybe you understand the AO trick more clearly in the Variation 3 image. I am sure we can use that data for many things once we target that channel?