HOW TO USE IT

To use that you just need to "Append" the 'Smart Terrain.blend" file to your scene, selecting the "TERRAIN" inside the "Object" folder.

 After that you should see that a new terrain mesh was added to your scene.

Select the terrain and go to the Modifiers tab, here you will gonna find a Geometry Nodes tool that is generating the terrain.

Load the render camera into the "Render Camera" input. (This is a very important step, as all of the optimization of the relies on it.)

Load your Displacement Map on the input in the modifier.

OPTIMIZING

Use the "Base Terrain Resolution" to set the lowest resolution of the terrain.

Use "Adaptive Terrain Resolution" to set how far from the camera the terrain will gonna be subdivided.

 Use the "Render Resolution Multiplier" to subdivide the terrain even more.

Use the "Viewport Resolution", Viewport Subdivision Multiplier" and the "Bounding Box Trees" to optimize how the terrain is shown on the viewport, while keeping all of the quality for the render time.

ADDING TREES

To instantiate the trees, you need to create a new collection and add all of trees with it's origins set the to the bottom of the4 mesh. Load it on the "Tree Collection" input and increase the density until it fills the area that you want.

TEXTURING

To use textures with the terrain, you musty to go on the Shader Editor with the terrain material selected, add a "Attribute" node and connect the vector to the vector of all of the textures used in the material.