I am surprised the doc don't mention at all what we need to do to prepare textures and prefabs for grass rendering. https://docs.unity3d.com/Manual/terrain-Grass.html Since Paint Tree tool affects Nav Mesh (it marks the terrain un-walkable; unless we use the Nav Mesh Components from GitHub, which I believe have some extra options), the only proper way to add walkable grass is to use Paint Detail tool, but they are limited to 2 hidden shaders from TerrainEngine folder. It would be great to know: - What texture does the billboard shader expect? Black-and-white? - What structure does the detail prefab need? Must be a MeshRenderer/MeshFilter at the root object? It seems LOD/Multi-materials are not supported, but the doc didn't mention them in any way. Please share if you have the knowledge!