You can use either the Image element or the VisualElement.style.backgroundImage
property to add visual content to your UI. The choice between the two depends on the specific requirements of your application. For more information, refer to Image versus VisualElement.style.backgroundImage
.
You can use an imported or built-in image asset to set a background image. When you set the background image, you must select a supported background image type:
When you import an image to your project, define the image import settings for the best results.
You can set the background image in UI Builder, directly in USS, or in C# files. For more information about referencing project assets, refer to AssetsAny media or data that can be used in your game or project. An asset may come from a file created outside of Unity, such as a 3D Model, an audio file or an image. You can also create some asset types in Unity, such as an Animator Controller, an Audio Mixer or a Render Texture. More info
See in Glossary.
UI Builder:
4. Click in the Image field to select an image asset from your project.
USS example:
MyElement {
background-image: url("path/to/imageFile.png");
}
C# example:
// Use the AssetDatabase method to load the texture.
myElement1.style.backgroundImage = AssetDatabase.LoadAssetAtPath<Texture2D>("path/to/imageFile.png");
// Use the AssetDatabase method to load the sprite.
myElement2.style.backgroundImage = new StyleBackground(AssetDatabase.LoadAssetAtPath<Sprite>("path/to/spriteAssetFile.png"));
// Load the texture from the project's Resources folder.
myElement3.style.backgroundImage = Resources.Load<Texture2D>("imageFile");
// Load the sprite from the project's Resources folder.
myElement4.style.backgroundImage = new StyleBackground(Resources.Load<Sprite>("spriteAssetFile"));
// Use the Unity Editor's default resources.
myElement5.style.backgroundImage = EditorGUIUtility.FindTexture("CloudConnect");
myElement6.style.backgroundImage = Background.FromTexture2D(EditorGUIUtility.IconContent("FolderOpened Icon").image as Texture2D);
Scale mode for a background image defines how the image scales to fit the visual elementA node of a visual tree that instantiates or derives from the C# VisualElement
class. You can style the look, define the behaviour, and display it on screen as part of the UI. More info
See in Glossary.
The supported scale modes for a background image.
A: stretch-to-fill
that stretches the image to fill the entire area of the visual element.
B: scale-and-crop
that scales the image to fit the visual element. If the image is larger than the visual element, the image is cropped.
C: scale-to-fit
that scales the image to fit the visual element. It’s similar to the stretch-to-fill mode, but the aspect ratioThe relationship of an image’s proportional dimensions, such as its width and height.
See in Glossary of the image is preserved.
You can set the scale mode in UI Builder, directly in USS, or in C# files.
USS example:
MyElement {
-unity-background-scale-mode: scale-and-crop;
}
C# example:
// Set the scale mode to scale-and-crop.
myElement.style.backgroundPositionX = BackgroundPropertyHelper.ConvertScaleModeToBackgroundPosition(ScaleMode::ScaleAndCrop);
myElement.style.backgroundPositionY = BackgroundPropertyHelper.ConvertScaleModeToBackgroundPosition(ScaleMode::ScaleAndCrop);
myElement.style.backgroundRepeat = BackgroundPropertyHelper.ConvertScaleModeToBackgroundRepeat(ScaleMode::ScaleAndCrop);
myElement.style.backgroundSize = BackgroundPropertyHelper.ConvertScaleModeToBackgroundSize(ScaleMode::ScaleAndCrop);
Generally, you can apply the 9-slice technique to a regular 2D Sprite. However, with UI Toolkit, you can apply the 9-slice technique to Texture, Render Texture, and SVG Vector images.
To apply 9-slice, set the following:
-unity-slice-scale
by the sprite’s pixels-per-unit
value in relation to the panel’s reference sprite pixels per unit value
, which is by default 100
. For example, if the sprite’s pixels-per-unit
is 16
, the scale is adjusted by 16/100 = 0.16
. Therefore, if you set the scale to 2px
, the final scale is 2px * 0.16px = 0.32px
. For texture and vector images, Unity doesn’t make additional adjustments to the slice scale value you set.sliced
or tiled
. The Sliced type scales the center, while the Tiled type tiles the center and sides.You can set the slice values and slice scale with UI Builder, or directly in USS, or in C# files. For a sprite image, you can also set the values in the Sprite Editor.
UI Builder:
Use the Slice fields in the Background section to set the slice values, slice scale, and slice type.
USS example:
MyElement {
-unity-slice-left: 10px;
-unity-slice-right: 10px;
-unity-slice-top: 10px;
-unity-slice-bottom: 10px;
-unity-slice-scale: 2px;
-unity-slice-type: tiled;
}
C# example:
MyElement.style.unitySliceLeft = 10px;
MyElement.style.unitySliceRight = 10px;
MyElement.style.unitySliceTop = 10px;
MyElement.style.unitySliceBottom = 10px;
MyElement.style.unitySliceScale = 2px;
MyElement.style.unitySliceType = SliceType.Tiled;
Important:
Sliced vs Tiled
You can use -unity-slice-type
to have the center and sides of the slice tiled instead of streched.
To properly support tiling, import the image as a Sprite (2D and UI) and set the MeshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary Type to Full Rect.