Create a new script in your project. Give the script the same file name and class name as the Terrain Tool you want to create. The basis for all Terrain tools is the `TerrainPaintTool` class in the `UnityEditor.TerrainTools` namespace. `TerrainPaintTool` is an abstract generic class.
return "This is a very basic Terrain Tool that doesn't do anything aside from appear in the list of Paint Terrain tools.";
}
}
```
The example above is a good starting point to create a custom tool from scratch. **Basic Custom Terrain Tool** now displays as an option in the **Paint Terrain** dropdown menu.
If you want to specify a category in the dropdown menu, you can add categories and subcategories such as `Category/SubCategory1/SubCategory2/Custom Terrain Tool`. Make sure to replace `Category`, `SubCategory1`, and `SubCategory2` with the actual category and subcategory names you want to use.
The image below shows an **Examples** category, which contains the **Basic Custom Terrain Tool**.