Tutorial — USD for Maya

Augmented Traveler local tutorial. Back to Maya — Tutorials · process: Maya — Process

How Augmented Traveler uses USD (Universal Scene Description) from Maya. The main use is getting props and set pieces into Unreal, Apple Vision Pro and iPhone AR from one source file.

Draft. Written from Autodesk's USD for Maya documentation and release notes. Validate on the first prop (the Mitchell telescope) and correct menu names here.

1. Where USD fits, and where it doesn't

Use USD for Don't use USD for
Props and set pieces: telescope, desk, ledger, chronometer, Vestal House furniture MetaHuman characters. They go through DCC Export, Character Assembler and DNA/FBX (MetaHuman for Maya — Considerations)
One asset with variants (book open or closed; brass polished or worn; day or night room) Skinned garments on the MetaHuman. Those follow the Marvelous Designer USD → Cloth Asset route in Unreal (Marvelous Designer to MetaHuman — Considerations)
Handing assets to Apple surfaces (Reality Composer Pro for Vision Pro; AR Quick Look on iPhone, which needs USDZ) Mocap takes and skinned meshes (FBX; see Tutorial — FBX Export Presets for Unreal)
Inspecting a Marvelous Designer USD garment before it goes to Unreal

2. Versions

3. Set-up

  1. Turn on the plug-in: Windows → Settings/Preferences → Plug-in Manager → mayaUsdPlugin → Loaded and Auto load.
  2. Units: Maya works in centimetres, and USD records this as metersPerUnit = 0.01. Unreal and Apple tools read it, so model to real size and don't rescale on export.
  3. Up axis: Maya is Y-up. Leave it; Unreal converts on import. Apple tools expect Y-up.
  4. Folders, one per asset: Assets/Props/<AssetName>/, holding the USD asset, its textures and a src/ folder with the Maya file.

4. Build one prop as a USD component

  1. Model the prop to real dimensions, with clean UVs and two LODs: _LOD0 for the kiosk and Quest desktop, _LOD1 for headsets and phones.
  2. Materials: use USD Preview Surface (or MaterialX through LookdevX) with base colour, roughness, metallic and normal maps.
    • USD Preview Surface is the safest choice for Apple AR Quick Look and converts cleanly into Unreal.
    • Refine the Unreal look in Unreal, not in Maya.
  3. Create the component: select the prop's objects → Component Creator. This writes a structured USD asset (geometry, materials, payload) instead of one flat file.
  4. Add variants in the Variant Manager, for example:
    • state: closed / open (ledger);
    • finish: polished / worn (telescope);
    • lod: LOD0 / LOD1.
  5. Save and check it in the USD Layer Editor: one root layer and no stray edit layers.

5. Edit an existing USD asset in Maya

  1. Open it as a stage: Create → Universal Scene Description (USD) → Stage from File.
  2. To change geometry: right-click the prim → Edit As Maya Data. Make the change, then Merge Maya Edits to USD.
  3. To change a property only (a transform, a variant choice, a material binding), edit it on the stage. Choose the target layer in the Layer Editor first, so the change lands in the right file.
  4. Garments from Marvelous Designer: open the USD to inspect scale, thickness and intersections. Send fixes back to Marvelous Designer when you can, because a garment edited in Maya drifts from its pattern.

6. Export to each surface

Surface How Check
Unreal 5.8 (kiosk, Quest, Vive) Turn on the USD Importer plug-in → import the component (or open it in the USD Stage editor to keep variants live) Scale, pivot at the base, materials connected, LODs present
Apple Vision Pro Bring the USD into Reality Composer Pro Materials look right under RealityKit lighting; polygon budget per Hardware — Deployment Specifications
iPhone AR Quick Look (postcards) Package as USDZ. Use the exporter's USDZ option if your USD for Maya version has it; otherwise use Apple's Reality Converter or usdzip Real size on a table; opens in Quick Look from Files or Safari; file size fits the App Clip budget

7. Rules

8. Practice exercise

  1. Model a simple ledger with two variants: closed and open.
  2. Build the component, add the variants and save.
  3. Import it into Unreal and switch the variant in the USD Stage editor.
  4. Export a USDZ and open it on an iPhone with AR Quick Look at real size.
  5. Record every snag here and correct this tutorial.

Sources