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globalobjectid [2021/02/08 09:15]
uninomiconadmin [Converting a Prefab Gid to an Unpacked Gid]
globalobjectid [2021/02/11 20:36] (current)
uninomiconadmin
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 //All notes below only apply to running the game in Play mode in the Editor.// //All notes below only apply to running the game in Play mode in the Editor.//
  
-When a scene is loaded in play mode, prefabs are unpacked ((I've seen this mentioned in the profiler as Prefabs.MergePrefabs, during [[engine:scenemanager]] scene loads.)) into standard game-objects. These gameobjects have a different GID than the original prefab. However the GID of the unpacked GameObjects is *still* unique and stable!+When a scene is loaded in play mode, prefabs are unpacked ((I've seen this mentioned in the profiler as Prefabs.MergePrefabs, during [[scenemanager]] scene loads.)) into standard game-objects. These gameobjects have a different GID than the original prefab. However the GID of the unpacked GameObjects is *still* unique and stable!
  
 For example. You may have a prefab in the scene with GID: For example. You may have a prefab in the scene with GID:
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 ''%%(%%prefabGid.targetObjectId ^ prefabGid.targetPrefabId) & 0x7fffffffffffffff'' ''%%(%%prefabGid.targetObjectId ^ prefabGid.targetPrefabId) & 0x7fffffffffffffff''
  
-<codedoc toggle Example Code>+++++ Example Code
 + 
 +<code csharp>
 private static GlobalObjectId ConvertPrefabGidToUnpackedGid(GlobalObjectId id) private static GlobalObjectId ConvertPrefabGidToUnpackedGid(GlobalObjectId id)
-  +
-            ulong fileId = (id.targetObjectId ^ id.targetPrefabId) & 0x7fffffffffffffff; +    ulong fileId = (id.targetObjectId ^ id.targetPrefabId) & 0x7fffffffffffffff; 
-            bool success = GlobalObjectId.TryParse( +    bool success = GlobalObjectId.TryParse( 
-                $"GlobalObjectId_V1-{id.identifierType}-{id.assetGUID}-{fileId}-0", +        $"GlobalObjectId_V1-{id.identifierType}-{id.assetGUID}-{fileId}-0", 
-                out GlobalObjectId unpackedGid); +        out GlobalObjectId unpackedGid); 
-            Assert.IsTrue(success); +    Assert.IsTrue(success); 
-            return unpackedGid; +    return unpackedGid; 
-        +
-</codedoc>+</code> 
 + 
 +++++ 
 + 
 +===== Bug: Querying deleted objects ===== 
 +When calling ''GlobalObjectId.GlobalObjectIdentifiersToObjectsSlow'' with a GlobalObjectId that was assigned to a now-deleted object, the Object returned will sometimes be a valid, arbitrary Object in the project, rather than the correct value of ''null''
 + 
 +For example, in this case, when passed an array of only scene objects: 
 +{{ :hdmvjaumtf.png?direct&400 |}} 
 + 
 +The function will return non-scene objects (the shader editor asset at 205).  
 +{{ :is0bzbpnb6.png?direct&400 |}} 
 + 
 +This seems to be a bug. The correct result should have been ''null'', because that GID was deleted. 
 + 
 +I have had some luck <sup>[//[[:wiki:tag:dark-magic|dark magic]]//]</sup> querying these 'bad' GIDs individually with ''GlobalObjectIdentifierToObjectSlow''. This seems to properly return null in certain cases. This does not cure all cases, however((Luckily, there was only a small set of objects that were valid to be stored by my GIDs, and so I could discard any GIDs resolving to the wrong type.)).
  
 +Update: This is fixed in 2021.1 [[https://issuetracker.unity3d.com/issues/globalobjectidglobalobjectidentifierstoobjectsslow-sometimes-returns-a-random-existing-gameobject|bug tracker]].
  
globalobjectid.1612775753.txt.gz · Last modified: 2021/02/08 09:15 by uninomiconadmin