class `PrefabIdRemapper`

Helper class that allows prefab instance hierarchy remap their IDs for use within prefab internals.

This includes game object ID, prefab object ID and prefab resource ID. Examples are provided below for better understanding - the main purpose of this class is find the original IDs from within the prefab, from an instance of that prefab (or assign new IDs if that is not possible).

////////////////////////////////////////////////////////////////////////////////////////////////////////// The mapping of instance -> prefab is as follows: All objects within the prefab internal hierarchy will have a unique game object ID. All instance objects of that prefab will have a prefab object ID pointing to that game object ID, and prefab resource ID pointing to the prefab resource.

For example: Prefab #1 (Resource ID=PFB1) internal hierarchy: Root [Game Object ID=OB11, Prefab Object ID=OB11, Prefab Resource ID=PFB1] My object [Game Object ID=OB12, Prefab Object ID=OB12, Prefab Resource ID=PFB1]

Instance of Prefab #1 Root [Game Object ID=OBI1, Prefab Object ID=OB11, Prefab Resource ID=PFB1] My object [Game Object ID=OBI2, Prefab Object ID=OB12, Prefab Resource ID=PFB1]

////////////////////////////////////////////////////////////////////////////////////////////////////////// A prefab may contain nested prefabs, but this is not reflected in the instance of that prefab. An instance of a prefab will link directly to its parent prefab. Information about nested prefabs is instead stored in the parent prefab resource's internal prefab hierarchy. There prefab object ID and prefab resource ID will point to the nested prefab. If that nested prefab contains nested prefabs in itself, that information is stored in the nested prefab resource's internal prefab hierarchy, and so on.

For example: Prefab #2 (Resource ID=PFB2) internal hierarchy: Root [Game Object ID=OB21, Prefab Object ID=OB21, Prefab Resource ID=PFB2]

Instance of Prefab #1 Root [Game Object ID=OBI1, Prefab Object ID=OB11, Prefab Resource ID=PFB1] My object [Game Object ID=OBI2, Prefab Object ID=OB12, Prefab Resource ID=PFB1] Prefab #2 instance [Game Object ID=OBI3, Prefab Object ID=OB13, Prefab Resource ID=PFB1]

////////////////////////////////////////////////////////////////////////////////////////////////////////// The above means that generally there is only ever a single level of prefab nesting as visible from the prefab internals hierarchy. One exception are prefabs that are added to a nested prefab, but this change doesn't get applied to the nested prefab resource. In such case those prefabs are treated as instance modifications, and will result in multiple levels of nesting within the hierarchy.

For example: Prefab #3 (Resource ID=PFB3) internal hierarchy: Root [Game Object ID=OB31, Prefab Object ID=OB31, Prefab Resource ID=PFB3]

Prefab #2 (Resource ID=PFB2) internal hierarchy: Root [Game Object ID=OB21, Prefab Object ID=OB21, Prefab Resource ID=PFB2] // Note PFB3 is not part of this prefab

Prefab #1 (Resource ID=PFB1) internal hierarchy: Root [Game Object ID=OB11, Prefab Object ID=OB11, Prefab Resource ID=PFB1] My object [Game Object ID=OB12, Prefab Object ID=OB12, Prefab Resource ID=PFB1] Prefab #2 instance [Game Object ID=OB13, Prefab Object ID=OB21, Prefab Resource ID=PFB2] Prefab #3 instance [Game Object ID=OB14, Prefab Object ID=OB31, Prefab Resource ID=PFB3] // Links directly to PFB3, as it's an instance modification of PFB1, and not part of PFB2

If we were to apply the change to PFB2 within PFB1, PFB3 becomes part of PFB2, and PFB1 then links only to PFB2: Prefab #3 (Resource ID=PFB3) internal hierarchy: Root [Game Object ID=OB31, Prefab Object ID=OB31, Prefab Resource ID=PFB3]

Prefab #2 (Resource ID=PFB2) internal hierarchy: Root [Game Object ID=OB21, Prefab Object ID=OB21, Prefab Resource ID=PFB2] Prefab #3 instance [Game Object ID=OB22, Prefab Object ID=OB31, Prefab Resource ID=PFB3] // PFB3 now nested prefab of PFB2

Prefab #1 (Resource ID=PFB1) internal hierarchy: Root [Game Object ID=OB11, Prefab Object ID=OB11, Prefab Resource ID=PFB1] My object [Game Object ID=OB12, Prefab Object ID=OB12, Prefab Resource ID=PFB1] Prefab #2 instance [Game Object ID=OB13, Prefab Object ID=OB21, Prefab Resource ID=PFB2] Prefab #3 instance [Game Object ID=OB14, Prefab Object ID=OB22, Prefab Resource ID=PFB2] // This instance now links to PFB2

////////////////////////////////////////////////////////////////////////////////////////////////////////// As may be seen from examples above, if an object within internal prefab hierarchy is not part of a nested prefab, its prefab object ID will be equal to its game object ID, and resource ID point to the prefab resource it is contained in.

Public

Constructors

PrefabIdRemapper

PrefabIdRemapper(const HSceneObject &originalPrefabHierarchy, const UUID &rootPrefabId, const SPtr<GameObjectCollection> &newGameObjectCollection)

Methods

RestoreOriginalPrefabIds

UnorderedMap<UUID, UUID> RestoreOriginalPrefabIds(const HSceneObject &hierarchyRoot)

Updates all objects in with IDs so they match previously stored prefab hierarchy.

Returns a map containing a remapping from instance game object IDs to prefab game object IDs, which may be used for updating the original scene object hierarchy, so it links to the created/updated prefab hierarchy.

Private

Methods

GetOrPopulatePrefabInformation

const PrefabInformation &GetOrPopulatePrefabInformation(const UUID &prefabResourceId)

Finds the prefab associated with the scene object instance, and populates a lookup from instance ID to { prefab object id, prefab resource id }.

If a prefab has already been processed, cached data will be returned.

DeduceInternalPrefabIds

PrefabObjectIdAndLinkInformation DeduceInternalPrefabIds(const UUID &prefabObjectId, const UUID &prefabResourceId, const SceneObjectInformation &associatedSceneObjectInformation, i32 nestingLevel = 0)

Attempts to find existing instance ID, prefab object ID and prefab resource ID for in the active prefab.

prefabObjectId: Object ID to perform lookup for.
prefabResourceId: Resource ID of the prefab in which to perform lookup for.
associatedSceneObjectInformation: Information about the associated scene object for the object we're looking up the IDs for.
nestingLevel: Incremented by one each time search into a nested prefab. Should be 0 when initially called.

Returns: Instance ID, prefab object ID and prefab resource ID for . If active prefab contains information about , existing information will be returned, otherwise new instance ID will be generated and prefab object ID and prefab resource ID extracted from provided data

AssignInternalPrefabIds

void AssignInternalPrefabIds(GameObjectHandle &gameObject, const UUID &gameObjectIdInPrefab, const PrefabLinkInformation &linkInformationInPrefab, const UUID &rootPrefabResourceId, i32 nestingLevel)

Assigns original prefab game object ID, prefab object ID and prefab resource ID to the provided game object.

The original prefab IDs refers to the IDs stored when a game object is part of the internal prefab hierarchy.

gameObject: Game object to which to assign the IDs to.
gameObjectIdInPrefab: ID of the game object within the prefab hierarchy, as output by DeduceOriginalPrefabIds().
linkInformationInPrefab: Link information to nested prefabs, as output by DeduceOriginalPrefabIds().
rootPrefabResourceId: ID of the prefab resource that the resulting hierarchy will be stored in.
nestingLevel: Current depth of nested prefab we are at. 0 for root, 1 for first nested prefab, etc.

Fields

mPrefabCache

UnorderedMap<UUID, PrefabInformation> mPrefabCache

mPrefabId

UUID mPrefabId

ID of the prefab we're restoring IDs for.

mNewGameObjectCollection

SPtr<GameObjectCollection> mNewGameObjectCollection

Game object collection to use for remapping the object IDs.