VisionOS Image Tracking

Question

As I am trying to run the application with the vision Pro, I receive following error:

ar_image_tracking_provider_t <0x303d45340>: Failed to set up image tracking with error: No images were supplied.

i did add images in Assets under a “ref” folder. so normally it should work

this is my function

import Foundation
import RealityKit
import ARKit
import RealityKitContent


var arkitSession = ARKitSession()
@MainActor class ARKitViewModel: ObservableObject{
    
    private let session = ARKitSession()
    private let imageTracking = ImageTrackingProvider(referenceImages: ReferenceImage.loadReferenceImages(inGroupNamed: "ref"))
    var entityMap : [UUID: ModelEntity] = [:]
    func runSession() async {
        Task {
            do {
                try await arkitSession.run([imageTracking])
            } catch {
                print("Error: \(error)")
            }
        }
    }
    var material = SimpleMaterial()

    var rootEntity = Entity()
    func updateImage(_ anchor: ImageAnchor) {
        if entityMap[anchor.id] == nil {
            let entity = ModelEntity(mesh: .generateSphere(radius: 0.05))
            entityMap[anchor.id] = entity
            rootEntity.addChild(entity)
            entity.transform = Transform(matrix: anchor.originFromAnchorTransform)
        }
    }
    
    
    
    func processUpdates() async {
        for await _ in imageTracking.anchorUpdates{
            print("test")
        }
    }
}

i don't know why it failed to set up and basically i am trying to use this code to detect an object ,static one? exemple of these photos:

Answer 1

Creating AR Resource Group

You have to put images under a ref.arresourcegroup folder (which has an adhoc json file that created automatically), not under a regular ref folder. To do that, create you ref folder in Assets using contextual menu (do not specify .arresourcegroup extension, this folder will receive it automatically):

Place your 480x480 reference images in this folder and adjust their real-world size in the Inspector. You must use high-contrast, well-discernible, RGB-only (no Alpha-transparency) images. Also, avoid gradients and single-solid-colors in your reference images. Try to use colors that have an ideal contrast in black-and-white version of this image. Try not to use repetitive patterns like stripes or polka dots.