This is a paid asset, but now you can download Terrain To Mesh Free.
Detail this asset from Unity Asset Store: Original Link
Terrain To Mesh v2020.5 (Latest version)
Terrain To Mesh v2019.5
Terrain To Mesh v2018.3
Terrain To Mesh v1.43
“If possible, please buy the package to support the developer”
Tool for converting Terrain to mesh.
• Ultra fast converter.
• Vertex count control.
• Chunking system.
• Splatmaps exporter.
• Basemap exporter (diffuse and bump) *.
• Heightmap exporter.
• Tree exporter.
• OBJ file exporter.
• All above works in editor and run-time.
Includes shaders for blending 2 to 8 textures. Shaders support mobile (Unlit and One Directional Light), Legacy and PBR shading models.
Shaders are Curved World compatible.
Scriptable render pipeline shaders available separately (link).
Have questions? Forum
Terrain To OBJ and All Terrain Textures can be purchased separately too.
Tool is already included in Mesh Materializer asset.
Scripts are packed in dll.
Basemap baking works only with Unity built-in terrain shaders.
Terrain hole system is not exported.