Using USD Stage in Unreal Engine: A Guide to Opening and Editing Scenes

What you’ll learn in this guide

Universal Scene Description (USD) is an open-source interchange format for organizing and transferring scene data between different 3D applications. In Unreal Engine, the USD Stage workflow lets you view and edit a scene hierarchy without immediately converting the file into native static meshes and materials. This guide covers opening USD Stage, changing a prim’s properties, adding a reference to another USD file, saving your work, and importing content into an Unreal Engine project.

This approach can make it easier for architecture and visualization teams working across multiple applications to inspect scene structure. However, keep in mind that the workflow is marked beta, some data types may not transfer identically between applications, and lightmaps require additional attention.

Requirements and preparation

Epic’s guide does not specify a particular Unreal Engine version or user account requirement. The documented prerequisite for setup is enabling the USD Importer plugin in your project. The editor must be restarted after enabling the plugin. The supported source USD formats are .usd, .usda, .usdc, and .usdz.

Before you begin, make sure the USD file you plan to use and its referenced assets are accessible. For multi-user workflows, team members need to access the same USD files using the same file path; Epic recommends keeping the files in the project folder and managing them with source control.

If you’re also planning to exchange files with Blender, assess the import scope beforehand. Blender’s USD importer supports data such as cameras, curves, lights, materials, meshes, point clouds, and volumes, but it does not yet handle some layer and reference concepts in USD composition. Don’t assume that every scene structure visible in one application will have a complete equivalent in the other.

Opening and editing USD Stage in Unreal Engine

1. Enable the plugin. In Unreal Editor, open the USD Importer plugin from the Plugins menu and restart the editor. The Window > Virtual Production > USD Stage option will then appear in the Level Editor.

2. Load a USD file. In the USD Stage panel, go to File > Open and select your file. Its prim hierarchy will appear in the panel. When the loaded USD content is connected to the Level, Unreal Engine creates a USD Stage Actor, which manages the representation of the USD data in the scene.

3. Inspect the scene structure. Select prims in the Hierarchy area of the USD Stage window, then view the selected item’s properties in the Properties area. For example, the upAxis property determines the scene’s up direction. If a prim has a modelingVariant, you can change the current variant in this area. The variant option appears only if the asset has one or more variants.

4. Add a prim and a reference. Right-click an appropriate item in the hierarchy and select Add Prim to create a new prim. Then right-click the new prim, select Add Reference, and choose the USD file to reference. You can choose whether the reference targets the default prim in the destination file or a specific prim path. You can use the scene’s transform tools to position the new item.

5. Save your changes. In the USD Stage panel, use File > Save. This command writes your Stage edits to the source USD file. For important scenes, use backup and file-management practices that suit your team’s workflow.

6. Import content into the project. When you need to convert the scene into Unreal Engine assets, use Action > Import in the USD Stage Editor. This method imports both assets and Actors, replacing items in the Stage with Actors created in the Content Browser. The Add/Import option and dragging the file into the Content Browser import assets only. File > Import Into Level imports both assets and Actors.

Animation, layers, and working with Blender

If the USD file contains animation, you can access Sequencer through the Level Sequence in the USD Stage Actor’s properties. USD xform animation appears as Transform tracks. You can also add a Transform track to an Actor connected to USD Stage later. In layered scenes, it’s important to place the animation in the correct layer: Epic’s quick start guide states that the animation layer must be higher in the stack than the scene layer it affects.

USD Stage Editor also supports adding references and payloads to prims, isolating layers, and duplicating prims. The result of duplication depends on the method you choose: for example, “Flatten Composed Prim” creates a new prim from the composed prim, while “Single Layer Specs” duplicates only prim specifications in the current edit target. Before using these options, check which layers will be affected.

There are a few details to consider when importing into Blender as well. For USDZ archives, you can choose how textures are imported: not importing textures may leave materials unresolved, while options are also available to package textures or copy them to a separate folder. Blender may also produce an approximate conversion of USD Preview Surface materials to Principled BSDF nodes, without preserving all shader settings. Test the result in a sample file before using it in production.

What should architecture and visualization teams consider?

Architecture firms, interior designers, and visualization teams can use USD Stage to inspect scene hierarchies from different sources, manage alternative prims or references, and review animations in Sequencer. Being able to inspect a large scene before converting it directly into native assets can be useful during the pre-transfer editing stage. However, this does not mean that every application feature will be preserved exactly.

Pay particular attention to lighting and material appearance. Epic notes that Unreal Engine does not automatically generate lightmaps for assets when USD Stage is opened; if static lighting is built, the scene may appear completely black. Material conversion when moving to Blender may be approximate, and limitations in layer and reference support can also affect scene structure. Before final delivery, validate lighting, materials, textures, animation, and hierarchy in the target application. Factor USD Stage’s beta status into production decisions as well.

Common mistakes and next steps

• Looking for USD Stage before enabling the plugin: Enable USD Importer and restart the editor.

• Assuming a reference copies an asset into the scene: A reference links to another prim or USD file; carefully choose the target file and prim.

• Overlooking USDZ textures: Check the import option; material textures may not resolve if you don’t import them.

• Not checking the result of static lighting: Keep in mind that assets coming from USD Stage do not have lightmaps generated automatically.

• Using different file paths in a multi-user session: Make sure team members access the USD file using the same path. Epic also notes that deleting a prim during a multi-user session cannot be undone.

Start with a small, representative USD scene. Compare its hierarchy, references, textures, and appearance in the target application before moving on to larger projects. Reviewing the supported data types in the Blender and Unreal Engine documentation can help reduce unexpected losses during file transfer.

Sources and license

This guide is based on Epic Games’ USD Stage quick start, USD overview, and working with prims documentation, as well as Blender Manual’s USD import and export documentation. The Blender Manual document is licensed under CC BY-SA 4.0; its content has been adapted into Turkish.