How to Use Unreal Engine Data Layers: A World Partition Guide

What will you learn in this guide?

In Unreal Engine, World Partition divides large maps into grid cells within a single persistent level, then loads and unloads those cells based on streaming sources. Data Layers help you group actors in a map and manage the state of those groups in the editor or at runtime. In this guide, you’ll learn how the two systems work together, how a Data Layer Asset differs from a Data Layer Instance, and how to create layers and assign actors to them.

Data Layers are a way to organize scene content and manage loading states. In architectural visualization scenes, they can be used to keep content such as building components, landscaping, and set dressing in separate groups. Which actors belong in which layers depends on the project’s organization; the source documentation does not recommend a specific layer template for architectural scenes.

Requirements and key concepts

The map you use Data Layers in must have World Partition enabled. According to Epic’s documentation, when creating a new level, you can select Open World via File > New Level. World Partition and Data Layers are enabled by default for this map type. To add World Partition to an existing level, you can use Tools > Convert Level or the World Partition conversion commandlet.

The official documentation does not specify the Unreal Engine version, account requirements, or minimum hardware needed for these steps. You should therefore also check that the version used by your project and your team’s workflow are suitable.

It’s important to distinguish between two key concepts:

• Data Layer Asset is a project-level asset that can be used in different worlds. It contains information such as the Data Layer name, type, and debug color.

• Data Layer Instance is an instance that belongs to a specific world. The same asset can be used in multiple worlds; each instance can have properties specific to its world.

A Data Layer Asset is assigned either the Editor or Runtime type. Editor Data Layers are used to edit, load, unload, and manage the visibility of assets in the editor. Runtime Data Layers can be managed during gameplay through Blueprint or C++. For example, an in-game event can load or unload assets assigned to a particular layer.

Setting up Data Layers: step by step

1. Open a map with World Partition enabled. To create a new map, go to File > New Level and select Open World. If you’re continuing with an existing map, consider the conversion option. Since conversion can affect the level structure, testing it in your project workflow before applying it to a production map is a cautious approach.

2. Create a Data Layer Asset. In the Content Browser, go to the folder where you want to store the asset. Right-click and select Miscellaneous > Data Layer. Saving the asset with a name that describes the content group it will contain can make it easier to find the right layer later in the Outliner. This is a workflow suggestion; the source documentation does not require a specific naming convention.

3. Add a Data Layer Instance. Open the Data Layers Outliner by going to Window > World Partition > Data Layer Outliner. Right-click in the Outliner and select Create New Data Layer. Assign the Data Layer Asset you created to the new instance using the drop-down menu. Alternatively, drag the asset into the Outliner to create a new instance. Dropping the asset onto an existing instance creates a child instance associated with the selected asset.

4. Assign actors to a layer. Select the actors you want to add in the viewport. Then right-click the target instance in the Outliner and select Add Selected Actors to Selected Data Layers. Another option is to use the Data Layers section in the selected actors’ Details panel. To assign a layer this way, the selected Data Layer Asset must have an instance in the world.

5. Choose a layer type based on how you’ll use it. Consider the Editor type if you want to edit content, load or unload it, or manage its visibility in the editor; consider the Runtime type if you want to manage it at runtime through Blueprint or C++. For example, keeping different environment variations in separate groups can make it easier to work on specific content in the editor. This is a suggestion for adapting the system to an architectural scene workflow; layer scope depends on the project’s needs.

6. Manage Runtime states. You can change the state of Runtime Data Layer Instances through Blueprint or C++. In Epic’s Blueprint documentation example, the Set Data Layer Instance Runtime State node is used. In the example, setting an instance to Loaded keeps it loaded but not visible in the level. When managing layers at runtime, don’t confuse loading with visibility; check the intended behavior in the scene.

7. Adjust the Outliner view as needed. The Data Layers Outliner is used to view existing instances and create new assets or instances. Its options let you hide Editor or Runtime Data Layers, hide unloaded actors from the list, and highlight instances that contain selected actors. These options can help simplify the view when working with many layers.

Using Data Layers in architectural and visualization workflows

Architecture firms, interior designers, and archviz teams can use Data Layers to organize content groups in large Unreal Engine scenes. Putting building surroundings, landscaping elements, and set-dressing actors in separate layers can make it easier to select and manage related content while working on a particular group. However, creating layers does not by itself define team tasks or file-sharing workflows; its primary function is to organize actors and manage their loading states.

Data Layers work alongside World Partition. World Partition divides the scene into grid cells and loads them based on streaming sources. Player controllers can be used as streaming sources, and you can also add a World Partition Streaming Source component. Data Layers, meanwhile, organize actors into logical groups and help structure large levels. Teams should first decide which content to group, then determine whether the layers will be controlled in the editor or at runtime.

In terms of performance, Epic notes that loading too many assets at once can cause problems. Assigning commonly used assets to many Runtime Data Layer Instances can also reduce World Partition streaming performance. This warning does not set a fixed limit on the number of layers, so you’ll need to monitor loading behavior under your project’s conditions. Using functional groups rather than creating a separate layer for every actor is a workflow suggestion for keeping the organization clear.

The sources do not specify a minimum hardware requirement, so it isn’t possible to conclude that a particular computer configuration will be sufficient. In large scenes, test the amount of content being loaded and how streaming behaves. Also verify with your team that the Unreal Engine version used by the project supports the conversion and Data Layers workflow.

Common mistakes

Skipping the World Partition requirement: Data Layers require a map with World Partition enabled. Check that the map meets this requirement before creating layers.

Treating an asset and an instance as the same thing: The asset exists at the project level, while the instance belongs to a specific world. Make sure you assign the instance you created in the Outliner to the correct asset.

Confusing Editor and Runtime types: Editor Data Layers are intended for editing and visibility management in the editor; Runtime Data Layers are intended to be controlled through Blueprint or C++ during runtime. Choose the type that fits your use case.

Ignoring loading costs: Loading too many assets at once, or assigning commonly used assets to many Runtime Data Layer Instances, can affect performance. Validate your layer structure with a small test.

Next steps

Start with a small test using only a few actors: create one Editor Data Layer and one Runtime Data Layer, assign actors to them, and check visibility and loading states in the Outliner. If you need to make changes at runtime, manage the Runtime Data Layer states through Blueprint or C++.

Teams converting an existing level can use the -ReportOnly option in the World Partition documentation to generate a report on what the conversion will do. This option does not perform the conversion. Check the commandlet’s available options and the structure of the source level; don’t apply untested changes directly to a production scene.

For larger scenes, consider the Data Layers setup together with World Partition cells and streaming sources. Epic also notes that using multiple runtime grids can negatively affect performance. Testing the layer and streaming setup in your own project before moving it into a production scene can help identify potential loading issues early.

Sources and license

This guide has been adapted into Turkish based on Epic Games’ official Unreal Engine Data Layers and World Partition documentation. Both sources are identified as freely licensed in the source information provided.