I’m quite new to Unreal and have trouble with the child/parent definition.
What I’m trying to do :
I have a parent actor, its purpose is to hold the utility functions I need and to be a parent of new actors.
This parent actor has a function that is callable in editor. This function uses the SpawnActor node to create some new actors from a given BP.
This function also sets the spawned actors to bet children of the parent actor via Attach Actor to Actor.
The problem that I have is, when I call the function in editor, everything works fine, the children are correctly bound to the parent but as long as I save the project, they no longer are children of the parent actor.
Note that they no longer have any parent, they go back to the root of my level.
I have tried many things, in particular trying to modify the parent (as it doesn’t appear in the unsaved actors). I have also tried to set the children as children of a scene in the parent actor via Attach Actor to Component. I have also tried to modify the parent actor to be a Editor Utility Blueprint but it didn’t change anything (this is the version shown on the screenshots).
Do you have any idea of what is happening ? Is this a correct way to setup this kind of child/parent relationship or should I use another method ?
I would like to understand what’s going wrong rrather than just a dirty fix, as I would like to use this kind of relationships for other actors in my game.
I wonder if you have a construction script or another script that resets the parent of those child actors? Could you share a screenshot of your Blueprint? It would be easier to identify the issue.
Basically it’s two for loops for the two axis of the grid, I call SpawnActor at a given location. Then I store the children in an array. The, after the for loop, I iterate over the array to attach all the spawned actors.
Once again, everything works fine until I save my project. Also if I save by quitting the project, it seems to be saved properly.
I understand the issue you’re experiencing. It’s not related to your blueprint; rather, it’s related to the OneFilePerActor feature in Unreal. This feature stores your actor data separately instead of directly in the map file. To confirm this, please create a basic level and try again.
Don’t worry if you lose your hierarchy. Just reopen your map, and everything will work properly.
You can also use ChildActorComponent to spawn them as child, that way child actors always belong to component and component will belong to parent and it should always load the same.
Creating a new basic map worked ! Thanks a lot for your help
Just to be sure, I saw on the documentation page of OneFilePerActor that its main use is for source control when different people are working on the same project. Since I’m working alone, I shouldn’t need it right ?
