Reality Composer 未正确导入 RealityKit

Question

I'm trying to anchor a 3d model onto a real-world image, in my case a QR code... It works fine within Reality Composer, however, I attempted to add it into my RealityKit project and nothing is showing up in my ARView... Nothing relevant is printed in the console.

Here is my code:

struct MainARView: UIViewRepresentable {

    func makeUIView(context: Context) -> ARView {

        let view = ARView()
        let session = view.session
        let config = ARWorldTrackingConfiguration()      
        session.run(config)

        view.debugOptions = [.showFeaturePoints, 
                             .showAnchorOrigins, 
                             .showAnchorGeometry]
           
        guard let anchor = try? TestObj.loadScene() else {
            print("Error loading TestObj")
            return view     
        }       
        view.scene.addAnchor(anchor)
        return view
    }
    func updateUIView(_ view: ARView, context: Context) { }
}

Any help would be much appreciated

Answer 1

In your case, there's no need to run ARWorldTrackingConfig or ARImageTrackingConfig .

Unlike ARKit , RealityKit automatically tracks all your AnchorEntities based on Target's cases ( .object , .image , .plane , etc). Reality Composer has already created AnchorEntity(.image) for you, so ARImageTrackingConfig was automatically assigned to the session.

import SwiftUI
import RealityKit

struct ARViewContainer: UIViewRepresentable {

    func makeUIView(context: Context) -> ARView {

        let arView = ARView(frame: .zero)
        let qrCodeModel = try! Experience.loadModel()
        arView.scene.anchors.append(qrCodeModel)
        return arView
    }
    func updateUIView(_ uiView: ARView, context: Context) { }
}

In addition to the above, here's a way to create the same scenario in RealityKit from scratch.

struct ARViewContainer: UIViewRepresentable {
    
    func makeUIView(context: Context) -> ARView {
        
        let arView = ARView(frame: .zero)
        let entity = ModelEntity(mesh: .generateBox(size: 0.125))
        let anchor = AnchorEntity(.image(group: "AR Resources", 
                                          name: "QRCode.png"))
        entity.setParent(anchor)
        arView.scene.anchors.append(anchor)
        return arView
    }
    func updateUIView(_ uiView: ARView, context: Context) { }
}