Quick answer: Player needs a streaming source component. Check runtime grid size encompasses player position. Verify cells aren’t marked as “Editor Only”.
An open-world game uses World Partition. Player walks toward a region; assets don’t stream in. The area looks empty. Streaming source isn’t configured.
Streaming Source Required
Add to player pawn or camera:
- Component → Add → Streaming Source Component.
- Configure Default Visualizer Loading Range (e.g. 5000 units).
Without this, World Partition has no “who’s here” signal and doesn’t load.
Runtime Grid Settings
World Partition asset → Runtime Grids. Configure:
- Cell Size: spatial grid resolution (default 25600cm).
- Loading Range: per-grid range.
- Priority — higher priority loads first.
For high detail, use smaller cells; bigger ranges mean more memory.
HLOD Visibility
If cells don’t load but HLOD displays a placeholder, you see distant geometry but no interactive content. Verify HLOD has been generated for the grid.
Console Debugging
wp.Runtime.ShowRuntimeHash 1
wp.Runtime.LogActorLoading 1Shows grid cell visualization (color = streaming state) and logs each actor load/unload event.
Verifying
Walk through level. Cells stream in as you approach loading range. Console output confirms loads. No empty regions near the player.
“Streaming source + grid + HLOD: three pillars of World Partition. Each must be configured.”
For multiplayer, each player counts as a streaming source. Server may load all union of player regions — significant memory; tune carefully.