Functionality#

Import/Open (From USD)#

Functionality	Description
Geometry	Static Meshes Skeletal Meshes Blendshapes (as Morph Targets) Introduced in 201.0
Animation	Audio2Face Facial Animations Skeletal and Blendshape Animation Clips Introduced in 202.0
Materials	Preview Surfaces MDL
Textures	UDIM/Virtual Textures Introduced in 202.0
Cameras	USD Camera attributes mapped to Cinematic cameras
Lights	USD Distant Light (as Directional) USD Rect Light (as Rect) USD Sphere Light (as Point) USD Dome Light (as sky sphere mesh and sky material) Introduced in 101.1 USD Lights with IES Profiles Introduced in 102.6

Export (To USD)#

Functionality	Description
Geometry	Export to USD w/ Skeleton Nanite mesh exported brute-force as geometry (Unreal Engine 5.0) Static Mesh Collision data Landscapes Grass textures Introduced in 101.1 Foliage Brushes Text Actors
Animation	Skeletal Mesh animation export Level Sequence Actor export (if Autoplay checked)
Materials	Preview Surfaces MDL Export: Native translation
Cameras	Cinematic camera attributes mapped to USD Cameras
Lights	Directional Light (as USD Distant) Point Light (as USD Sphere) Spot Light (as USD Sphere) Rect Light (as USD Rect)
Postprocess	Some exposure settings saved with stage export
Blueprints	Meshes, Lights, Cameras, SceneComponents, etc. within a Blueprint are exported as USD after the Construction Script is run
Groom Asset Introduced in 100.4	Meshes, Lights, Cameras, SceneComponents, etc. within a Blueprint are exported as USD after the Construction Script is run

Live Workflow#

Functionality	Description
Stage Editing	Actor transformations Actor addition/removal Receive mesh deformation from other clients
Material Syncing	Material assignment Material Instance parameter changes

Missing Functionality & Limitations#

The Unreal Engine is vast and has many varied authoring pipelines and asset types. For now the Omniverse USD and MDL plugins are targeting a subset of those that are useful and it will continue to grow. Listed below are some of the items that are not supported, but note that this list doesn’t cover everything.

Packaging#

For now the Omniverse USD and MDL plugins are only supported in editor mode. They cannot be run in “-game” mode or used as a packaged, shipping project. If an OmniverseStageActor is used within a level it will not cook properly.

Blueprints#

Logic Run in a Blueprint is not yet translated into any sort of compute logic within USD. A Blueprint’s components are exported to USD in whatever state that they exist after the Construction Script is run. Note that if a user wishes to capture Blueprint motion as timesamples, Unreal’s Sequence Recorder may be used and then exported as USD timesamples.

Level Sequences#

Only linear keyframes are supported in the USD import/export. On export, a cubic, or any native Unreal keyframe will be translated into per-frame, linear timesamples. On import, linear USD timesamples will be imported as linear Unreal keyframes.

Materials#

When exporting unsupported material functions watch the Message Log for notifications. Not all material functions map to MDL properly, so they are often replaced with a constant value.

These material functions are not supported (incomplete list):

Complicated Custom HLSL Material Expressions that use code that doesn’t align with MDL

Atmospheric Light Vector

Atmospheric Light Color

Atmospheric Fog Color

Pixel Depth

Scene Color

Camera Vector/Position

Object Position/Radius

Field of View

View Property

Light Vector

Bump Offset

Fresnel

IOR from texture lookup

Media texture sampler

Particle

Particle Color

Particle Direction

Particle MacroUV

Particle PositionWS

Particle Radius

Particle Random

Particle RelativeTime

Particle Size

Particle Speed

Particle SubUV

Commandlet Limitations#

The export commandlet will only export maps, not individual meshes or materials.

The export commandlet will not properly export maps with multiple levels.

The export commandlet must be run with the -AllowCommandletRendering flag to support text render actors and USD Preview Surface