Method SetParent

Source/Engine/Level/Actor.cpp:299–408

}

void Actor::SetParent(Actor* value, bool worldPositionsStays, bool canBreakPrefabLink)
{
    if (_parent == value)
        return;
#if USE_EDITOR || !BUILD_RELEASE
    if (Is<Scene>())
    {
        LOG(Error, "Cannot change parent of the Scene. Use Level to manage scenes.");
        return;
    }
#endif

    // Peek the previous state
    const Transform prevTransform = _transform;
    const bool wasActiveInTree = IsActiveInHierarchy();
    const auto prevParent = _parent;
    const auto prevScene = _scene;
    const auto newScene = value ? value->_scene : nullptr;

    // Detect it actor is not in a game but new parent is already in a game (we should spawn it)
    const bool isBeingSpawned = !IsDuringPlay() && newScene && value->IsDuringPlay();

    // Actors system doesn't support editing scene hierarchy from multiple threads
    if (!IsInMainThread() && (IsDuringPlay() || isBeingSpawned))
    {
        LOG(Error, "Editing scene hierarchy is only allowed on a main thread.");
        return;
    }

    // Handle changing scene (unregister from it)
    const bool isSceneChanging = prevScene != newScene;
    if (prevScene && isSceneChanging && wasActiveInTree)
    {
        OnDisableInHierarchy();
    }

    Level::ScenesLock.Lock();

    // Unlink from the old one
    if (_parent)
    {
        _parent->Children.RemoveKeepOrder(this);
        _parent->_isHierarchyDirty = true;
    }

    // Set value
    _parent = value;

    // Link to the new one
    if (_parent)
    {
        _parent->Children.Add(this);
        _parent->_isHierarchyDirty = true;
    }

    // Sync scene change if need to
    if (isSceneChanging)
    {