Epic Games Unreal Datasmith (UDATASMITH) Writer

FME can write data in the Unreal Datasmith format.

The Datasmith version created by FME is supported in Unreal Studio version 4.21 and higher.

Unreal Datasmith Product and System Requirements



Operating System


FME Desktop License

FME Server

FME Cloud

Windows 64-bit




Available in FME Professional Edition and higher




Yes (Ubuntu only) 64-bit



Epic Games Unreal Datasmith (.udatasmith) is a file standard that is used to import 3D scenes into Unreal Engine projects. Datasmith folders contain Assets such as meshes and textures. These Assets are used to create a .udatasmith file, which contains a scene hierarchy of Unreal Engine Actors (instances). Multiple Actors can be associated with the same Assets, and each Actor can also contain a set of metadata keys and values.

UDATASMITH files are organized in a hierarchical structure:


FME Representation



Writer Dataset

A file that contains a group of Assets and Actors.


Feature Type

A group of related Actors in a Scene.


Geometry Instance

An instance of a game object, which may contain other Actors. An Actor usually references one or more Assets.


Appearance, Texture, Raster, or Geometry Definition

A file that contains data used to render one or more Actors in a Scene.


Attribute or Trait

A key and value in an Actor's metadata dictionary.

The writer dataset is a folder where FME will write asset files and a scene file.

Each FME Feature Type will be represented as a Layer in the scene. For each geometry on an FME feature, the writer will create an Actor in the scene. If the geometry can be represented as a surface, then the writer will create an associated mesh asset. If the geometry has one or more appearances, then the writer will create associated material and texture assets. Feature attributes and geometry traits are written as a metadata dictionary attached to each Actor.

Note: The Unreal Datasmith format is limited to 32-bit precision for its coordinates and, as a result, translations involving a greater level of precision (that is, using world coordinates instead of local coordinates) may produce data where different coordinates are collapsed into a single coordinate. You can resolve this issue by offsetting the x,y,z coordinates such that the model's origin is moved to (0,0,0) or another point close to this, which has the effect of moving the model into a local coordinate system.

Texture Formats

UDataSmith supports the following texture formats:

  • JPEG
  • PNG