World Partition in Unreal Engine 5.5

Introduction

• Building large maps traditionally required manual division into sublevels and level streaming.
• Challenges included sharing files and viewing the world context.
• World Partition automates data management and streaming, removing the need for sublevels.
• Worlds are stored in a single persistent level, divided into grid cells for streaming.

Key Features

• Automatic Streaming: Loads and unloads cells based on distance from the streaming source.
• Works with features like:
  • One File Per Actor
  • Data Layers
  • Level Instancing
  • Hierarchical Levels of Detail

Enabling World Partition

Options:

1. Creating New Project: Use the Games template.
2. Open World Template: Default for large open-world maps.
3. Convert Existing Levels: Use tools or commandline for conversion.

Creating via Games Template

• Default enabled in Games templates.
• Streaming can be toggled in World Settings.

Open World Default Map

• Comes with essential features enabled (e.g., World Partition, Data Layers).
• Sample 2 km x 2 km landscape provided.

Converting Existing Levels

• Use Convert Level menu or commandlet for conversion.
• Command structure: UnrealEditor.exe -run=WorldPartitionConvertCommandlet
• Optional arguments available for customization.

Actors in World Partition

• Automatically assigned to grid cells based on settings.
• Individual files for changes, no need to check out Level file.
• Streaming based on actor references.

Streaming Sources

• Player Controllers and other components can act as streaming sources.
• Custom streaming sources can be added.

Runtime Grid Settings

• Determines grid cell loading/unloading.
• Located in World Settings' World Partition Setup.
• Default 2D Runtime Hash grid.

Loading/Unloading Regions

Using World Partition Window

• Manually select and load regions in the Editor.

Using Location Volumes

• Add volumes in the level to represent map regions.

Minimap Generation

• Use Build Minimap option or commandlet to generate.
• Enable Virtual Textures if Minimap doesn't appear.

Shortcuts/Options

• Hotkeys for snapping selection, moving camera, and loading regions.

Hierarchical Levels of Detail (HLODs)

• Built using Build HLODs option or commandlet.
• Creates HLOD Actors for World Partition cells.

Cooking World Partition World

• Use Cook commandlet for packaging.
• Command: UnrealEditor.exe -run=cook -targetplatform=WindowsNoEditor

Using World Partition with Blueprint

• Supports both Blueprint Classes and Level Blueprints.
• Blueprint Classes preferred for Always Loaded actors.

Debugging and Runtime Overrides

• Console commands available for debugging.
• Examples include toggling runtime hash display, setting loading ranges, and showing without HLODs.

Builder Commandlets

• Automate processes like HLOD and AI Nav Data generation.
• Avoids the need to load large worlds for certain operations.

For more information, refer to Epic Developer Community on World Partition in Unreal Engine 5.5.