# Editing Global Terrain


> **Notice:** Manual terrain modification is demonstrated in the [Arbitrary Terrain Generation](https://youtu.be/L_Wb-oylt_Y?t=853) video tutorial.


The built-in terrain editor allows you to change the *[Global Terrain](../../objects/objects/terrain/terrain_global/index.md)* relief on the spot with the help of brushes. In the editing mode, you can draw various terrain features, such as rocky ground and other craggy details. All brushes modify only the selected LOD.


To start editing an **already generated** *Global Terrain* (it is generated using the *[Sandworm](../../editor2/sandworm/index.md)* tool), select *Terrain Global Paint Mode* on the [toolbar](../../editor2/interface/index.md#tools_panel).


You can also click the **Brush Edit** button in the *Terrain Global* section of the *Node* tab in the *[Parameters](../../editor2/interface/index.md#parameters)* window.


![](edit_terrain.png)


The following *Active Tool* window will open:


![](active_tool.png)


## Controls


- To draw with a brush, press ***ALT + LMB***.
- To grab the height / color / material (depending on the brush type) at the current height of terrain and set it as a brush value, use ***ALT + RMB***.
- To change the brush size, use the *mouse wheel*.


The information on controls is also available at the bottom of *Active Tool*.


## Editing Modes


The following modes with their specific settings are available for modifying *Terrain Global*.


| ![](albedo_brush.png) | **Albedo brush** modifies the color of a albedo texture that is assigned to the surface. |
|---|---|
| ![](heights_brush.png) | **Heights brush** adds hills and cavities of different sizes. |
| ![](mask_brush.png) | **Mask brush** controls the clarity and spreading of details across the *Terrain Global*. The **Mask** dropdown allows you to choose a mask from the list of available ones for the current terrain. |


## Parameters


Every mode has a set of parameters allowing to configure the terrain visual representation.


| Shape | Shape of the brush: - ![](shape_circle.png) � circle shape - ![](shape_square.png) � square shape - ![](shape_custom.png) � loading a custom texture-based brush |
|---|---|
| Mode | Available editing modes: - ![](mode_replace.png) **Replace** � apply the settings defined for the selected Brush in the *Parameters* depending on the selected editing mode (albedo, height, or mask) to the corresponding *Terrain Global* data on the selected layer and/or LOD. - ![](mode_add.png) **Add** � add the value specified by the brush settings (albedo, height, or mask) to the corresponding *Terrain Global* data on the selected layer and/or LOD. - ![](mode_subtract.png) **Subtract** � subtract the value specified by the brush settings (albedo, height, or mask) from the corresponding *Terrain Global* data on the selected layer and/or LOD. - ![](mode_smooth.png) **Smooth** � blur albedo, height, or mask edges blending and softening the transitions. |
| LOD | Albedo, height, or mask LOD of the *Terrain Global* to be modified with the brush. |
| Rotate | Rotation of a non-circular brush. Can be used to make brush fit best for a specific task. |
| Size | Size of the brush, in units. Determines the area to be affected by the brush. |
| Color | Color of the brush. |
| Intensity | Intensity of the brush. *Lower* intensity values correspond to darker albedo colors, or a more translucent (less intense) texture for masks, while *higher* values � to brighter colors, or a more opaque texture. |
| Opacity | Rate at which the brush is applied. *Lower* values create a more translucent brush, and *higher* values create a more opaque brush. |
| Sharpness | Tip of the brush. The *lower* the value, the sharper and smaller the tip. The *higher* the value, the flatter and bigger the tip. |
| Height | Height value for the brush. This value is added, subtracted or applied at the corresponding point of the heightmap. |


> **Notice:** - After using the Albedo brush, do not forget to regenerate a coarse albedo texture, so that introduced color changes would be seen on all levels of detail.
> - After using the Heights brush, do not forget to regenerate a normal map so that new relief features would be correctly lit.