I felt like this should be obvious because it's such an important use case for dropping RealityKit scenes into the world without user interaction, but I tried a few things with translation that failed.
For some reason what worked for me was calling box.setPosition.... relative to nil. I'm not sure why it works given that the documentation says "nil" means "world space", when it appears to behave as if nil means "parent space" in this case?
class Model: ObservableObject {
var wall: AnchorEntity?
var child: ModelEntity?
}
struct ImmersiveView: View {
@StateObject var model = Model()
var body: some View {
RealityView { content in
let wall = AnchorEntity(.plane(.vertical, classification: .wall, minimumBounds: [2.0, 1.5]), trackingMode: .continuous)
model.wall = wall
let mesh = MeshResource.generateBox(size: 0.3)
let box = ModelEntity(mesh: mesh, materials: [SimpleMaterial(color: .green, isMetallic: false)])
model.child = box
wall.addChild(box, preservingWorldTransform: false)
content.add(wall)
box.setPosition([0, 0, 0], relativeTo: wall)
} update: { content in
if let box = model.child, let wall = model.wall {
// box.setPosition([0, 0, 0], relativeTo: wall) // <---- DOES NOT WORK
box.setPosition([0, 0, 0], relativeTo: nil) // <---- DOES WORK even though nil means "world space"????
}
}
}
}
