Terrain3D

An editable terrain system for Godot 4, written in C++.

Features

Written in C++ as a Godot gdextension plugin, which works with official engine builds
Geometric Clipmap mesh terrain (as used in The Witcher 3)
Up to 16k x 16k, sliced up in non-contiguous 1k regions (think multiple islands without paying for 16k^2 vram)
Up to 10 levels of detail (LODs)
Up to 32 textures
Sculpting, texture painting, texture detiling, paint colors or wetness
Supports importing heightmaps from HTerrain, WorldMachine, Unity, Unreal and any tool that can export a heightmap (raw/r16/exr/+)

See the Wiki for more details on project status, features, design, and usage.

Download the latest release and extract the files, or build the plugin from source.
Run Godot, using the console executable so you can see error messages.
Import the project folder and open it. Let it complain about importing errors and likely crash. Then restart Godot.
If the demo scene doesn't open automatically, open demo/Demo.tscn. You should see a terrain. Run it. If you don't see terrain, look at the console for errors, and in Project Settings / Plugins to ensure that Terrain3D is enabled.

Copy addons/terrain_3d to your project folder in addons/terrain_3d.
Open Godot and go through the first load process & crash. Restart if needed.
In Project Settings / Plugins, ensure that Terrain3D is enabled.
Create or open a scene and add a new Terrain3D node.
Select Terrain3D in the scene tree. In the inspector, create a new Terrain3DStorage resource.
Click the down arrow to the right of the storage resource and save it as a binary .res file. This is optional, but highly recommended. Otherwise it will save terrain data as text in the current scene file.
Read the wiki to learn how to properly set up your textures, import data and more .

Read through the Wiki, especially Troubleshooting.
Search through the issues for known issues, or create a new one if you're sure it's not a duplicate.
Join the Tokisan discord server and look for the Terrain3D section.