# Building Masks The mask builder works by toggling filters or/and a noise together. These masks allow to automatically apply the Sub-Layer Material on the terrain. The functions described below applies to the whole mask and not the individual filters. ![](https://3751470283-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F9KuznrlYB4kqrVq5qJMd%2Fuploads%2Fp1ImWLfVJLAlOv3GQcgM%2FMask_1.png?alt=media\&token=a9a0456a-6cb5-40a1-92db-ad3d3f5f5f66)

Number	Function
1	Changes how the masks act with the manually drawn areas of the Sub-Layer. See Manual Sub-Layer Drawing for more information.
2	Clicking on the rectangle shows the color picker, to change the color of the layer when in LOOKDEV View. See LOOKDEV View for more information.
3	Contrasts, Increase/Decrease force of the Sub-Layer mask. The Force multiplies the mask by itself to increase its force. The steps values steps down the values instead of letting them smooth if set to a value greater than 0. The "Start from white mask" sets the mask to start to 1 instead of 0.

The **"Contrain Mask to Sub-Layer"** options allows you to constrain the Mask of the current Sub-Layer to one or more Sub-Layers, as long as they are under the Sub-Layers being edited and have valid masks.

The Sub-Layer 2 (Green) is constrained
to the Sub-Layer 1 (Red).

The next page will show in more detail each filters.