To mask text in Unity, you typically use a combination of a UI element (like TextMeshPro), a graphic element (like an Image) to act as the mask, and the built-in Unity UI Mask component. This allows you to reveal or hide parts of the text based on the shape of the masking element.
Here is a step-by-step guide based on common Unity practices, incorporating the provided reference points:
Steps to Mask Text in Unity UI
Masking text in Unity involves setting up a parent-child hierarchy with the mask object being the parent and the text object being a child. The parent object will have the Mask component, and its graphic will define the area where the child text is visible.
Step 1: Create a UI Element (Text)
First, you need the text object you want to mask. This can be a standard UI Text element or, more commonly, a TextMeshPro text object for better quality and features.
- In the Unity Editor, go to
GameObject > UI. - Select
Text - TextMeshPro. If prompted, import the TMP Essentials. - Position this text element within your UI canvas.
Step 2: Create a Masking Image (Parent)
Next, create the UI element that will act as the mask. This element should be a parent of the text object created in Step 1. An Image component is commonly used for this.
- In the Unity Editor, go to
GameObject > UI > Image. This will create a new Image. - Drag the TextMeshPro object (from Step 1) onto this newly created Image object in the Hierarchy. This makes the Image the parent and the TextMeshPro the child.
- The size and shape of this Image will determine the visible area of the text.
Step 3: Add a Mask Component
The core of the masking functionality comes from the Mask component. Add this component to the parent Image object.
- Select the Image object (the parent) in the Hierarchy.
- In the Inspector, click
Add Component. - Search for and select
Mask.
Step 4: Assign the Masking Image
The Mask component uses the graphic on the same GameObject (the Image in this case) to define the masking area. Ensure the parent object has a graphic assigned (like a Source Image on the Image component). The Mask component will automatically use this graphic.
- The Mask component usually has a toggle like
Show Mask Graphic. When enabled, the graphic itself is visible and acts as the mask. When disabled, the graphic is invisible but still acts as the mask.
Step 5: Adjust Mask Type (Optional but Relevant)
The Mask component doesn't have a 'type' property directly, but its behavior is governed by the graphic used and the Mask component's properties. The key property is typically the graphic's alpha channel. Pixels in the child content will only be rendered where the mask graphic has sufficient alpha (typically > 0).
Step 6: Position and Scale
Position and scale the parent Image object to define the masking area. The child text object should be positioned relative to the parent. Only the parts of the text that fall within the bounds and the visible shape (defined by the graphic and alpha) of the parent Image will be displayed.
- Adjust the
Rect Transformof the parent Image to set the masking area. - Adjust the
Rect Transformof the child Text object to position the text within the mask area.
Step 7: Fine-tune and Test
Run your scene to test the masking effect. Adjust the position and size of both the parent mask object and the child text object as needed to achieve the desired visual outcome.
- Experiment with different
Source Imageassets on the parent Image component to change the shape of the mask (e.g., a circle, a star, a custom shape).
Conclusion
By following these steps – creating the UI elements, establishing a parent-child relationship, adding and configuring the Mask component on the parent, and positioning the elements correctly – you can effectively mask text and other UI elements in Unity.
