Official Deprecating Sprite Packer Legacy

We are in the process of deprecating Sprite Packer Legacy(SpriteAtlas packing through option of PackingTags in the TextureImporter settings). However we are still allowing existing Assets to continue working with the following constraints :

1. The Packing Tags box in Texture Importer is now read-only.
2. Atlases based on Packing Tags are not automatically packed. Requires calling the script using IPreprocessBuildWithReport
3. Editor Packer Settings only shows Disabled and SpriteAtlas options

We strongly recommend that you start using the SpriteAtlas system which has better functionality, however if for some reason you wish to continue using PackingTags you may need to add the following Editor script.

Editor Settings no longer displays Legacy Sprite Packer options:


Custom Script to force Packing Atlas for Packing Tags:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEditor;
4. using UnityEditor.Build;
5. using UnityEditor.Build.Reporting;
6. using UnityEngine;
7. class BuildPreProcessor : IPreprocessBuildWithReport
8. {
9.     public int callbackOrder { get { return 0; } }
10.     public void OnPreprocessBuild(BuildReport report)
11.     {
12.         EditorSettings.spritePackerMode = SpritePackerMode.BuildTimeOnly;
13. UnityEditor.Sprites.Packer.RebuildAtlasCacheIfNeeded(BuildTarget.StandaloneWindows64, false);
14.     }
15. }
16.  

Note:

BuildPreProcessor

class inherits from

IPreprocessBuildWithReport

, thus it only triggers when building


To migrate existing tag based Atlas to SpriteAtlas, please use the following conversion Script:

Code (CSharp):

1. using UnityEditor;
2. using UnityEngine;
3. using System.Collections;
4. using System.Collections.Generic;
5. using UnityEditor.U2D;
6. using UnityEngine.U2D;
7.  
8. public class PrintAtlas : MonoBehaviour
9. {
10.     [MenuItem("Atlas/Print Usage")]
11.     static void AtlasedSprite()
12.     {
13.         Dictionary<string, List<string>> TagSpriteMap = new Dictionary<string, List<string>>();
14.  
15.         foreach (string s in AssetDatabase.GetAllAssetPaths())
16.         {
17.             TextureImporter ta = AssetImporter.GetAtPath(s) as TextureImporter;
18.             if (ta != null)
19.             {
20.                 if (ta.spritePackingTag != "")
21.                 {
22.                     if (!TagSpriteMap.ContainsKey(ta.spritePackingTag))
23.                     {
24.                         List<string> newList = new List<string>();
25.                         TagSpriteMap[ta.spritePackingTag] = newList;
26.                     }
27.                     TagSpriteMap[ta.spritePackingTag].Add(s);
28.                 }
29.             }
30.         }
31.  
32.         AssetDatabase.CreateFolder("Assets", "SpriteAtlas");
33.         foreach (var tagSprite in TagSpriteMap)
34.         {
35.             List<string> assetsforTag = tagSprite.Value;
36.             string alasPath = "Assets/SpriteAtlas/" + tagSprite.Key + ".spriteatlas";
37.             SpriteAtlas sa = new SpriteAtlas();
38.             AssetDatabase.CreateAsset(sa, alasPath);
39.  
40.             foreach (var asset in assetsforTag)
41.             {
42.                 Debug.Log(tagSprite.Key + " = " + asset);
43.                 Texture2D tex = AssetDatabase.LoadAssetAtPath<Texture2D>(asset);
44.                 sa.Add(new Object[1] { tex } );
45.             }
46.         }
47.  
48.         AssetDatabase.SaveAssets();
49.     }
50. }
51.  

 

Hi @travelsound84

1. If I now put one of my sprites into a SpriteAtlas, it still has the Packing Tag on it. Is that something I need to worry about?
No, once you migrated to Atlas (either using the scripts above) or manually please ensure that SpriteAtlas is set in Editor Settings -> SpritePacker Mode. PackingTag will be ignore while building SpriteAtlas Textures.
2. What about the settings on each sprite. Are they going to be overwritten by the settings on the SpriteAtlas? I'm talking about "Filter mode", "Compression" and other properties that I find in both places.
Legacy SpritePacker groups sprites based on PackerPolicy (configurable through Scripting Unity - Manual: Sprite Packer (unity3d.com) ). These settings are not migrated to SpriteAtlas automatically as each SpriteAtlas provides the ability to customize these settings per Atlas. Hence please ensure that you set these properties for each Atlas either through Inspector or through Scripting.

Please take a look at Unity - Manual: Sprite Atlas workflow (unity3d.com). Please do let us know if you need more info.