This is a paid asset, but now you can download Texture Forest Studio Free.
Detail this asset from Unity Store: Original Link
Texture Forest Studio v2.0 (Latest version)
A forest is an essential part of landscape. Usually trees are very close to each other in the forest. So close that there is virtually no space between adjacent trees.
In computer games, if we try to create a really dense wood it will cause significant FPS drop.
This is especially true for games where the player can rise to a considerable height and see the forest stretching to the horizon. In this case the frame can contain millions trees.
With the standard approach, computer game designers have to reduce the density of the forest to increase FPS. That usually looks unrealistic.
Texture Forest technology allows you to draw dense forest without reducing FPS. It involves the use of multiple texture layers which show the relevant sections of the forest.
Texture Forest technology works fast enough even on weak machines, though looking realistic.
Texture Forest Studio allows you to create your own forest texture sets which you can use with Texture Forest asset and separately.
At the next link you can fly over endless terrain with Texture Forest. Texture Forest WebGL.