Sprite Masks

Sprite Masks are used to either hide or reveal parts of a SpriteA 2D graphic objects. If you are used to working in 3D, Sprites are essentially just standard textures but there are special techniques for combining and managing sprite textures for efficiency and convenience during development. More info
See in Glossary or group of Sprites. The Sprite Mask only affects objects using the Sprite RendererA component that lets you display images as Sprites for use in both 2D and 3D scenes. More info
See in Glossary Component.

Creating a Sprite Mask

To create a Sprite Mask select from the main menu GameObject > 2D Object > Sprite Mask.

A new Sprite Mask GameObject is created in the Scene

Properties

Property	Function
Sprite	The sprite to be used as a mask.
Alpha Cutoff	If the alpha contains a blend between transparent and opaque areas, you can manually determine the cutoff point for which areas will be shown. You change this cutoff by adjusting the Alpha Cutoff slider.
Range Start	The Range Start is the Sorting Layer which the mask starts masking from.
Sorting Layer	The Sorting Layer for the mask.
Order in Layer	The order within the Sorting Layer.
Range End
Mask All	By default the mask will affect all sorting layers behind it (lower sorting order).
Custom	The range end can be set to a custom Sorting Layer and Order in Layer.

Using Sprite Masks

The Sprite to be used as a mask needs to be assigned to the Sprite Mask Component

The Sprite Mask GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary itself will not be visible in sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary, only the resulting interactions with Sprites. To view Sprite Masks in the scene, select the Sprite Mask option in the Scene Menu.

Scene view with Sprite Mask view turned on in the scene

Sprite Masks are always in effect. Sprites to be affected by a Sprite Mask need to have their Mask Interaction set in the Sprite Renderer.

The character sprites Mask Interaction is set to Visible Under Mask thus only parts of the sprite that are in the mask area are visible

By default a Sprite Mask will affect any sprite in the scene that has their Mask Interaction set to Visible or Not Visible Under Mask. Quite often we want the mask to only affect a particular sprite or a group of sprites.