Import terrain heightmap

World Machine from scratch:
- resolution: 1025x1025
- altitude: 1280 m
- Savefile: Valley3.tmd

Unity:
Terrain (Valley)
- size 8000x8000
- height: 1280
- heightmap resolution: 1025

- Add 16-bit raw heightmap file from WM to assets.
- Import Raw... (Valley.r16, Windows byte order)

- Add directional light:
Position (0,2000,0)
Rotation (35,0,0)

- Main Camera:
Pos (0,1000,0)
Rot (0,45,0)