# Unity — Process
**Role in the pipeline:** secondary engine, used only where it clearly beats Unreal:
1. **Apple Vision Pro mixed reality / shared space** via PolySpatial (Unreal supports full immersion only).
2. **Phone AR apps** via AR Foundation (one codebase for ARKit and ARCore), if native Swift/Kotlin teams are not available.
3. **Android XR**, if Unreal support stays in preview.
**Versions (Sept 2026):** Unity 6.3 LTS is the stable line; Unity 6.5 beta carries the latest Android XR features. AR Foundation 6.x.
## Bringing a MetaHuman into Unity
Allowed under the MetaHuman license since 2025, but costly:
- Export from Unreal (DCC export), often through Blender or Maya, into Unity (HDRP for fidelity, URP for XR).
- **Skin subsurface scattering and hair need custom shaders**; grooms do not transfer cleanly.
- Workflows can break with each Unreal or MetaHuman update.
**Rule:** for Unity targets, ship **baked, simplified** versions of the character (Optimized mesh, baked animation, card hair), never the live-rigged hero.
## PolySpatial (Vision Pro) constraints
- Apple silicon Mac + Xcode required; Unity 6 with visionOS build support.
- URP recommended; linear color only.
- **No custom ShaderLab shaders**, Shader Graph subset only; RealityKit does the rendering.
## Steps for a Unity deliverable
1. Export Optimized character + baked animation clips from Unreal (FBX or USD).
2. Rebuild materials in Unity (Shader Graph); swap hair to cards.
3. Import audio and caption tracks; sync to animation.
4. Build the AR or visionOS scene; test on device.
5. Keep the conversation client identical to Unreal's (same API and logging).
**Owners:** mobile AR engineer or visionOS developer. Tutorials: [[Unity — Tutorials]]