[I] - THE TERRAIN; VEGETATION AND WATER:
The map is 4096*4096
The landscape is randomly cast: Painting & vegetation.
At the end of the video, is a demo of the waves shader I could write using the leaves.shader on the water.shader.
The shader is in the workshop for free to use. It is far not perfect but it adds a good animation for ocean water.
[II] - THE CARS PHYSICS: