In this lesson, you will learn how to leverage the World Partition Editor and console commands to visualize streaming cells and pinpoint memory bottlenecks in your open-world environment.
Visualizing Streaming States
When performance hitches occur during movement, it is often due to the engine struggling to load or unload heavy grid cells. The primary tool for diagnosing this is the World Partition Editor window.
By opening this via Window > World Partition > World Partition Editor, you gain a bird's-eye view of your world’s spatial grid. Ensure you toggle the "Loading" filter in the editor settings; this allows you to see exactly which cells are active based on the Streaming Distance settings of your camera. If you notice a "stutter" when crossing a boundary, watch the editor to see if a massive cell—or a cluster of cells containing high-poly actors—is loading simultaneously.
Identifying Memory Bottlenecks
To confirm if your streaming setup is causing memory spikes, use the console command wp.Runtime.ToggleDrawRuntimeHash. This overlays the current streaming status directly into your viewport, color-coding cells as "Loaded" or "Unloaded."
If you suspect specific cells are too heavy, you can inspect them via the World Partition Explorer. Look for the "Memory" column or use the following command to print a summary of loaded actor counts:
wp.Runtime.ShowRuntimeSpatialHashCellInfo
This command prints information to your output log regarding how many actors and objects are currently residing in active memory. If you see a specific cell reporting an unusually high actor count, that cell is your bottleneck. You should either move some of those actors into a different grid or, better yet, offload them into Data Layers to prevent them from being loaded until specifically required.
By combining the spatial visualizer with memory logging, you can identify "hot spots" where streaming density exceeds your target memory budget. If a cell contains too many complex meshes or large collision assets, the streaming cost will inherently spike during cell transitions.
Key Takeaway: Use the World Partition Editor’s visual grid alongside the wp.Runtime console commands to correlate physical movement hitches with specific high-density streaming cells.