Connection

Unreal Bridge

The bridge separates source export from Unreal-side import, so assets and scene placement can be updated independently.

On this pageBridge controls What Update does in Unreal Source files beside the blend Remote execution

Bridge controls

Control	What it does
Refresh Instances	Scans for running `UnrealEditor.exe` processes and lets you choose the target project.
Export Assets	Writes FBX, texture files, and an `ImportData.txt` description for enabled structures.
Write Placement	Writes only collection and Geometry Nodes instance transforms to the current scene’s placement file.
Export Assets + Write Placement	Runs both source-data operations in one pass.
Update	Executes the Unreal-side Python update in the selected editor.
Convert Active Material	Serializes the supported active Blender material graph and recreates it as an Unreal Material.

What Update does in Unreal

Finds every generated *_ImportData.txt below the local Content source folder.
Imports missing assets and attempts native reimport for assets that already exist.
Imports referenced textures and reapplies their color, compression, wrapping, and filtering settings.
Applies LOD screen sizes, Nanite choice, sockets, simple collision, complex collision, and collision complexity.
Copies target materials into editable material instances and applies exported parameters.
Reads the current *_PlacementData.txt file and creates or updates level actors.

Source files beside the blend

For an asset named SM_Rock_A with Content/ set to Environment/Rocks/, B2ULink mirrors Unreal’s content hierarchy locally:

BlendFolder/Content/Environment/Rocks/SM_Rock_A/
├─ SM_Rock_A.fbx
├─ SM_Rock_A_ImportData.txt
├─ SM_Rock_A_ComplexCollision.fbx   (when used)
└─ Textures/

The Unreal asset path becomes /Game/Environment/Rocks/SM_Rock_A/SM_Rock_A.

Remote execution

B2ULink loads the remote_execution.py shipped with the selected Unreal installation. Unreal must expose a remote Python node before Blender can send the update script.