CODEWITHSUNDEEP
swiftswiftuiaugmented-realityarkitrealitykit
Auryn
Auryn

Reputation: 1176

Using ARKit anchor to place RealityKit Scene

I am currently struggling to add an RealityKit Scene to an ARKit anchor. As my previous question, it is not possible to directly add the RealityKit Scene to an ARKit Anchor Node.

But how can I use the ARKit Anchor to place my Scene? For example, I want to find an object in the room, and depending on which object I found, I want to use different scenes and anchor them in the room depending on the recognised objects position.

Thanks for the help.

Current try:

func makeUIView(context: Context) -> ARView {
        
        let arView = ARView(frame: .zero)
        
        // Load the "Box" scene from the "Experience" Reality File
        let boxAnchor = try! Experience.loadBox()
        
        // Add the box anchor to the scene
        arView.scene.anchors.append(boxAnchor)
        
        let configuration = ARWorldTrackingConfiguration()
        guard let referenceObjects = ARReferenceObject.referenceObjects(
                inGroupNamed: "AR Objects", bundle: nil) else {
            fatalError("Missing expected asset catalog resources.")
        }
        
        configuration.detectionObjects = referenceObjects
        arView.session.run(configuration) // not possible at arview, but i need arview for the .rcproject :-/
        
        return arView
        
    }

EDIT: add code

Upvotes: 2

Views: 3094

Answers (1)

Andy Jazz
Andy Jazz

Reputation: 58563

ARKit has no nodes. SceneKit does.

However, if you need to place RealityKit's model into AR scene using ARKit's anchor, it's as simple as this:

import ARKit
import RealityKit

class ViewController: UIViewController {
    
    @IBOutlet var arView: ARView!
    let boxScene = try! Experience.loadBox()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        arView.session.delegate = self
        
        let entity = boxScene.steelBox
        
        var transform = simd_float4x4(diagonal: [1,1,1,1])
        transform.columns.3.z = -3.0  // three meters away
        
        let arkitAnchor = ARAnchor(name: "ARKit anchor",
                              transform: transform)
        
        let anchorEntity = AnchorEntity(anchor: arkitAnchor)
        anchorEntity.name = "RealityKit anchor"
        
        arView.session.add(anchor: arkitAnchor)
        anchor.addChild(entity)
        arView.scene.anchors.append(anchorEntity)
    }
}

It's possible thanks to the AnchorEntity convenience initializer:

convenience init(anchor: ARAnchor)


Also you can use session(_:didAdd:) and session(_:didUpdate:) instance methods:

extension ViewController: ARSessionDelegate {
        
    func session(_ session: ARSession, didUpdate anchors: [ARAnchor]) {
            
        guard let objectAnchor = anchors.first as? ARObjectAnchor
        else { return }
            
        let anchor = AnchorEntity(anchor: objectAnchor)
        let entity = boxScene.steelBox
        anchor.addChild(entity)
        arView.session.add(anchor: objectAnchor)
        arView.scene.anchors.append(anchor)
    }
}

Upvotes: 4

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