Set background images

UI Builder doesn’t have a dedicated “image” element. To create an image, do the following:

1. Import a background image into your project.
2. Create a regular VisualElement in UI Builder.
3. Set the element’s background image to the imported image.

When you set the background image, you must select a supported background image type:

• Textures
• Sprites
• Render textures
• SVG Vector images

Note: To use an SVG image as a background for a VisualElement, you must install a package. To do so, in the Package Manager window, install the package com.unity.vectorgraphics from Git URL.

Image import settings

After you have imported an image to your project, for the most intuitive results, Unity recommends you to apply certain import settings for Textures, Sprites, and Vector images before you use them as a background for a visual element in the UI Builder.

Texture

The recommended import settings for a Texture image that you use as a background for a visual element:

属性：		值：
Texture Type		Default
	Non-Power of 2	无
	Compression	无
	Alpha Is Transparency	true
Texture Type		Editor GUI and Legacy GUI
	Non-Power of 2	无
	Compression	无
	Alpha Is Transparency	true
Texture Type		Sprite (2D and UI)
	Compression	无
	Alpha Is Transparency	true
	Sprite Mode	Single
	Mesh Type	Tight

Sprites

The recommended import settings for a Sprite image that you use as a background for a visual element:

属性：		值：
Texture Type		Sprite (2D and UI)
	Compression	无
	Alpha Is Transparency	true
	Sprite Mode	Multiple if file contains multiple sprites, Single otherwise
	Mesh Type	Tight

Vector images

The recommended import settings for a SVG Vector image that you use as a background for a visual element:

属性：	值：
Generated Asset Type	UI Toolkit Vector Image
Tessellation Settings	Basic
Target Resolution	Lowest value that produces satisfactory results

Tip:

• You can apply default presets to Assets by folder to automatically set your desired import settings.
• All image types are subject to dynamic atlasing if they’re not already in an atlas. (An image is in an atlas if imported as a Sprite with Sprite Mode set to Multiple, or if you have manually added it to a Sprite Atlas asset.) You can configure dynamic atlasing in a Panel Settings asset.

9-Slice images with UI Toolkit

Generally, you can only 9-slice a regular 2D Sprite. With UI Toolkit however, you can also 9-slice Texture, Render Texture, and SVG Vector images.

To 9-slice an image:

• For a Sprite image, use Sprite Editor or USS.
• For other types of images, use USS.

To 9-slice a selected image using USS:

1. Open UI Builder .
2. In the Background section in the Inspector, specify the Left, Right, Top, and Bottom slice values.

You can also specify the slice values directly in USS, UXML, or C# files for the following properties:

• -unity-slice-left
• -unity-slice-right
• -unity-slice-top
• -unity-slice-bottom
• -unity-slice-scale

Important:

• Slice values set using USS apply only to the image in the associated visual element. The values don’t apply to the same image used in other visual elements, in other UI documents, or in a scene.
• Unset slice value is zero. For example, if you set the Top,Bottom, and Right slice attributes but leave the Left slice empty, the Left slice is zero.
• Slice values set in USS override slice values set in the Sprite Editor. For the example above, no matter what value you added to the Left slice in the Sprite Editor, the Left slice value is zero.