The terrain authoring tools inside Unity are not great. This project was an exploration of a workflow where a terrain is authored completely within Houdini and then exported and converted to the Unity Terrain Data format.

The terrain also uses a custom shader to provide some more interesting lighting.

I use Houdini to render splat maps based on slope, flow, height, ambient occlusion etc.

Houdini also generates density maps for grass procedurally.