Authoring

Asset structures & export

B2ULink treats a reusable Static Mesh as a named collection structure with strict roles for every child collection.

Generated collection structure

Collection	Purpose
Main	Root of one B2ULink asset. It stores the asset-level export settings and must not directly contain objects.
Parent	Contains exactly one Empty. Exportable objects are parented to this Empty so the asset has a stable origin.
LOD0–LOD7	Mesh collections for the visible LOD chain. LOD0 is required; later populated LODs must be sequential.
SOCKET	Socket objects that are exported with the asset and recreated on the Unreal Static Mesh.
UBX / UCP / USP / UCX	Simple Unreal collision shapes: box, capsule, sphere, and convex hull.
ComplexCollision	A separate detailed collision mesh, exported to its own FBX and assigned after the main mesh import.
Asset	Generated wrapper/reference collection used when the same asset is linked, appended, or instanced elsewhere.
Dump	Objects stored with the structure but excluded from the final exported geometry.

Create builds the complete structure, moves selected objects into LOD0, and parents them to the generated Empty.
Rename Structure renames Main, its typed children, the Parent Empty, and detected instances consistently.
Refresh Structure restores canonical names, initializes LOD screen sizes, repairs generated wrapper data, and reparents complex collision objects.
Delete removes the selected generated structure. Use Blender undo immediately if this was accidental.

Setting	Effect
Export	Includes this structure in Export Assets. The Main collection must also be visible, render-enabled, and not excluded.
Pre/Post Delete Interior Faces	Removes detected interior faces before or after welding the temporary export copy.
Weld	Merges vertices by the configured distance. Only Non-Manifold limits the operation to non-manifold vertices.
Vgrp Remove Prefix	Removes vertex groups beginning with the prefix before export. The default is `Exc_`.
Export LOD	Imports populated LOD collections into Unreal. Enabling this disables Build Nanite.
Build Nanite	Exports LOD0 for a Nanite asset. Enabling this disables Export LOD.
Content/	The destination beneath Unreal’s `/Game` folder, such as `Environment/Rocks/`.
Collision Complexity	Chooses Project Default, Simple and Complex, Simple as Complex, or Complex as Simple.
Auto Screen Size	Lets Unreal derive LOD screen sizes instead of using the values stored on the LOD collections.

The .blend file must be saved and Blender must be in Object Mode.
Main cannot directly contain objects.
Parent must contain exactly one Empty with scale 1, 1, 1.
LOD0 must contain geometry. Later used LODs must be continuous without gaps.
Exported objects must be parented to the structure’s Parent Empty.
LOD mesh objects need materials; material slots may not be empty.
Material names cannot contain a period, and every used material needs its target Unreal material name.