Open Sample1 scene under the Packages/Mesh Terrain Builder/Samples folder:
Click the SampleTerrain1 game object from Hierarchy and locate the Mesh Terrain Builder component in the Inspector:
This is a Unity terrain with Mesh Terrain Builder component attached. To start converting and optimizing terrains,
you need to add the Mesh Terrain Builder component to the terrain game object.
Hitting the Generate Terrain Mesh button will start conversion with these settings.
After the conversion is complete, a new game object will be created at the same position with the terrain and
the original terrain game object will be disabled. The generated game object will have the same name with the name of the terrain data asset.