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Unity Engine

Create a sprite atlas

Create a sprite atlas, add sprites and textures to it, and analyze and optimize it.
Read time 3 minutesLast updated 23 days ago
Create a sprite atlas and pack sprites into it.
Note
You can also create multiple sprites from a single texture instead. For more information, refer to Import a sprite or spritesheet texture and Cut out sprites from a texture.

Prepare sprites for packing

To optimize the performance of sprite atlases and the memory they use, do the following for each texture you want to pack:
  • Disable Read/Write unless you read or write to the texture in C# scripts.
  • Enable Tight Packing to reduce the number of transparent pixels around the sprite.
Select Open Sprite Editor and check the following:
  • The Custom Outline tab, to make sure the outline fits closely to the sprite. For more information, refer to Crop a sprite.
  • The Secondary Textures tab, to make sure the sprite has the same number of secondary textures as the other sprites you want to pack it with. Otherwise the combined secondary textures in the sprite atlas might contain a lot of empty space. For more information, refer to Add normal map and mask map textures to a sprite.

Create a sprite atlas

To create a sprite atlas, from the main menu, go to Assets > Create > 2D >
Sprite Atlas

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.
Unity creates a file with a 
.spriteatlasv2
file extension in the Project window. Unity no longer uses Sprite Atlas V1 format by default. For more information, refer to Convert Sprite Atlas V1 assets.

Add sprites to a sprite atlas

For more information about assigning sprites to different sprite atlases, refer to Sprite atlases.
  1. In the Project window, select the sprite atlas asset.
  2. To add a sprite to the sprite atlas, drag a sprite from the Project window onto the Objects for Packing label in the
    Inspector

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    window.
    You can drag sprites, textures, or folders onto the Objects for Packing label. You can also select the Add (+) button in the Objects for Packing section.
  3. Select Pack Preview to display the packed texture in the Preview window at the bottom of the Inspector window.
If your textures have normal maps or mask maps as secondary textures, select the dropdown at the top-right of the Preview window to display the combined secondary textures.
Sprites now render using their sprite atlas texture in the Scene view, the Game view, and in Play mode. Unity also includes sprite atlases in your builds by default, and automatically loads and uses them at runtime.
Note
If you add a sprite to multiple sprite atlases, Unity randomly chooses which sprite atlas texture to use at runtime. To avoid this, refer to Load sprite atlases manually at runtime.

Use the original textures while editing

To use the original unpacked textures in the Scene view and Game view, but keep using the sprite atlas textures in Play mode and at runtime, follow these steps:
  1. From the main menu, select Edit >
    Project Settings

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    .
  2. Select Editor.
  3. In the Sprite Atlas section, set Mode to Sprite Atlas V2 - Enabled for Builds. Unity now builds and uses sprite atlases only when you enter Play mode or build your project.
For information on other Mode values, refer to Editor settings.

Additional resources