xra1

XRAI → visionOS (RealityKit)

Target: visionOS 2+, Apple Vision Pro. Reference impl Month 2 (hardware-gated).

Ingestion contract

import XRAIKit  // MIT package, ships Month 2

let graph = try XraiLoader.parse(data: jsonData)
let entity = try XraiSceneBuilder.build(graph: graph)
arView.scene.anchors.append(AnchorEntity(world: .zero))
arView.scene.anchors.first?.addChild(entity)

Mapping

XRAI	RealityKit
`entity.type = object.primitive`, `model_id = 0..5`	`MeshResource.generateBox/Sphere/...` + `ModelEntity`
`entity.type = object.glb`	Convert glTF → USDZ → `Entity.load(named:)` (glTFast-like bridge)
`entity.type = object.light`	`DirectionalLight` / `PointLight` / `SpotLight`
`entity.transform.position`	`entity.position = SIMD3<Float>(...)`
`entity.transform.rotation` (quat)	`entity.orientation = simd_quatf(ix: x, iy: y, iz: z, r: w)`
`entity.transform.scale`	`entity.scale = SIMD3<Float>(...)`
`entity.material.color`	`SimpleMaterial(color:, roughness:, isMetallic:)`
`relation.type = parent-of`	`parentEntity.addChild(child)`

Handedness

RealityKit: right-handed Y-up, meters (matches OpenUSD)
XRAI canonical: left-handed Y-up, meters (Unity native)
Loader negates z on ingestion unless graph.origin.handedness === "right"

Integration with USDZ ecosystem

XRAI can REFERENCE USDZ assets in entity.type = object.usdz (v1.1+ addition). This lets Apple’s ecosystem flow through XRAI graphs without forcing asset re-authoring.

Why matter for Portals strategy

Apple Design Award bait if Portals-on-visionOS ships first with voice-driven XRAI creation
Demonstrates XRAI is NOT Unity-locked — critical for open-standard credibility
Closed hardware but open format running on it

Status

Swift Package scaffold (XRAIKit)
Basic RealityKit bindings
Sample visionOS app on xrai.dev that loads scenes from URL
App Store submission (post-Portals-visionOS v1)

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