The Raise brush continuously raises the terrain under the mouse until you release the left mouse button.

The Lower brush continuously lowers the terrain under the mouse until you release the left mouse button.

The Set to brush allows you to set the terrain within the brush radius to a specific altitude.

When you select the set to tool, you will be prompted to enter the desired brush height, which is measured in metres above sea level. To help in choosing the correct brush height, the head-up display at the top left of the screen displays the height at the current mouse cursor position and height in the 'cur:' field (e.g. 260m, in example below left). The level of the chosen brush height is displayed by a second circle rendered in white, as shown below. This circle gives the position of the platform that will be created by the set to tool.

The set to brush is particularly useful for building platforms, such as that shown below:

A platform build by the set to brush, rendered in polygon mode.

The Raise to brush is a modification of the set to brush that only sets the terrain within the brush radius to the tool height if it is below the tool height. Note in the below image, the valley has been filled, while the hills to the back-left of the brush were unaffected:

A valley filled by the raise to brush.

The Lower to brush is a modification of the set to brush that only sets the terrain within the brush radius to the tool height if it is above the tool height. Note in the below image, the hills to the back-left of the brush have been clipped, while the valley is unaffected:

A hill clipped by the lower to brush.