AssetDatabase.CopyAsset changes GUID of target

We have a script that calls AssetDatabase.CopyAsset to overwrite an existing asset but when this happens Unity assigns a new GUID to the target asset breaking any references to the target asset in Unity.

Is there a reason the CopyAsset function modifies the target asset's GUID? It was my understanding that this was an extremely bad thing to do in Unity and I'm a little surprised that Unity itself is doing it.

 

It handles it as a new asset and every asset must have an unique identifier, thus it created a new guid. If you want to replace the content of an existing asset, use EditorUtility.CopySerialized instead.
https://docs.unity3d.com/ScriptReference/EditorUtility.CopySerialized.html

 

My question is why does it handle it as a new asset? It's an existing asset with its own GUID that simply gets discarded and replaced, breaking all references in Unity.

 

For me simple file copying worked as expected (at least I am not aware of some destructive side-effects):

Code (CSharp):

1.  
2. private static bool CopySceneAsset(string path, string newPath)
3. {
4.     var fullPath = Path.Combine(Application.dataPath, "..", path);
5.     if (!File.Exists(fullPath))
6.     {
7.         Debug.LogError(path + ": file not found.");
8.         return false;
9.     }
10.    
11.     var fullNewPath = Path.Combine(Application.dataPath, "..", newPath);
12.     if (File.Exists(fullNewPath))
13.     {
14.         File.Copy(fullPath, fullNewPath, true);
15.         return true;
16.     }
17.     else
18.     {
19.         return AssetDatabase.CopyAsset(path, newPath);
20.     }
21. }
22.  

 

EditorUtility.CopySerialized is not a useful API，Because when your original asset changed and execute EditorUtility.CopySerialized, the target asset is not update

 

Hi, so just a couple more lines will work for you but are you still looking? Weird such an old post is showing up top.