Hey! I upgraded from 5.5 → 5.6 last week and we use a lot of Child Actor Components. I think I found the reasons for the issue and a couple of solutions.
Disclaimer: I didn’t investigate deeply — I’m not an engine expert — but these fixes worked for us and might help others — refer to that for more technical details
Problem:
Variables set from the parent into the child actor are lost.
When does it happen?
In PIE (Play In Editor)
Not after cooking / packaged builds
Why:
Parent actor CS (construction script) is not executed
CAC (child actor component) are now respawning their child actor (more details), any setup done before is lost
Solution 1 (using CAC template):
Pros:
- Minimal changes required
Cons:
-
Can’t set actor references from world placement (illegal references)
-
Can only set instance editable variables (can’t edit BP added components) (I’m not sure on what exactly you can edit)
-
For the second case, probably not the intended workflow
if the CAC is not added in the CS and variable can be set in the BP, edit the CAC template in the details panel
otherwise, edit the CAC template in the CS
UFUNCTION(BlueprintPure, Category=ChildActorComponent)
static AActor* GetChildActorTemplate(const UChildActorComponent* ChildActorComponent);
AActor* UBlueprintFunctionLibrary::GetChildActorTemplate(const UChildActorComponent* ChildActorComponent)
{
if (ChildActorComponent)
return ChildActorComponent->GetChildActorTemplate();
return nullptr;
}
Solution 2 (Child CS):
Pros:
- No C++
- Probably the intended workflow
- More robust IMO
Cons:
- Different flow → more work in my case
- Makes child dependent on parent
- Child may always load the parent (I’m not sure about that after cooking, since the cast to the parent is in the CS)
Child actor reads required values from its parent in its Construction Script:
