@threenative/ueformat

A strict UEFormat v10 .uemodel parser and Three.js loader for assets exported from Unreal packages by CUE4Parse/FModel.

.uasset / .uexp / .ubulk / .pak / .utoc
                  ↓ CUE4Parse
              .uemodel
                  ↓ this package
     BufferGeometry / Mesh / LOD / Group

This package does not pretend that an isolated .uasset is a self-contained mesh. It handles the stable interchange boundary: CUE4Parse extracts UE4/UE5 packages, then this loader validates and constructs renderable Three.js objects.

Supported

• UEFormat v10 UEMODEL headers and named attribute sets
• uncompressed, GZIP, and injected-decoder ZSTD bodies
• static and skeletal mesh LOD records
• positions, normals, tangents, indices, multiple UV/color channels
• material sections as BufferGeometry.groups
• sparse morph targets
• skin indices/weights and skeleton metadata parsing
• sockets, virtual bones, and convex collision geometry
• Unreal centimeters/Z-up/left-handed coordinates to Three.js meters/Y-up/right-handed coordinates
• automatic winding and tangent-sign repair
• browser Loader.load, synchronous parse, and ueformat-inspect CLI validation

Not implemented

• Automatic texture/material extraction — .uemodel carries material slots (name, path, index range), not texture payloads. Resolve textures through your own pipeline (the asset MCP does this) and supply materials through materialFactory.
• Skeletal binding — parsed bones, sockets and skin weights are exposed on userData and as skinIndex/skinWeight attributes, but the package never constructs a THREE.SkinnedMesh or binds a skeleton. That is deliberately left to the game; nothing here invents it.
• ZSTD bodies require an injected zstdDecoder — the package never bundles a ZSTD implementation.

The look is the game's

Every material comes from the game through materialFactory. The fallback matches three.js's own GLTFLoader: a plain MeshStandardMaterial named after the slot. No colour, roughness, or metalness is decided here.

Provenance

Absorbed from the standalone three-ueformat-loader package (MIT, ThreeNative contributors, 2026) into the engine. The parser is pure TypeScript with no browser or Node globals — the same code runs in the browser, in Node, and on the native arm.