Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference

Context

PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spawns Instanced Actors, this creates Instanced Actors Managers with instances.

Problem

The created Instanced Actor Manager actors get MainGrid assigned as Runtime Grid, even if the PCGActor that spawned them didn’t have a Runtime Grid value (i.e. its None). Next time the map is loaded, this results in error messages:

Actor /Game/MAP_ReproPCG.PCG_PlaceInstancedActors references an actor in a different runtime grid /Game/MAP_ReproPCG.InstancedActorsManager_-1_-1_0
Actor /Game/MAP_ReproPCG.PCG_PlaceInstancedActors references an actor in a different runtime grid /Game/MAP_ReproPCG.InstancedActorsManager_0_-1_0
Actor /Game/MAP_ReproPCG.PCG_PlaceInstancedActors references an actor in a different runtime grid /Game/MAP_ReproPCG.InstancedActorsManager_-1_0_0
Actor /Game/MAP_ReproPCG.PCG_PlaceInstancedActors references an actor in a different runtime grid /Game/MAP_ReproPCG.InstancedActorsManager_0_0_0

Suggested Fix

The PCG actor and spawned IAMs runtime grids should match. If the PCG actor had it set to None, perhaps leave the IAMs value as None as well.

• Open attached repro project
• Open MAP_ReproPCG
• Observe: Map errors
• Select the actor PCG_PlaceInstancedActors
• Cleanup and regenerate
• Save the map
• Reopen the map
• Observe: Map errors
• Expected: No errors, i.e. generation should be adjusted to result in a valid setup