Get name of reference image swift ARKit 1.5 - swift

Question

Is someone know how can I get the name of the reference image red by the camera in AR?
I think that the Anchor is reading the identifier and connect it to the reference image that's returning name and physical size.
I want to have one AR Resources folder where I can put different images and then, in base of what the camera is recognize I want to display one model instead of another one.
Thank you very much!

Answer 1

An ARReferenceImage has the following properties which you can access:
var name: String?
A descriptive name for the image.
var physicalSize: CGSize
The real-world dimensions, in meters, of the image.
As such, in order to get the name of the reference image and other properties you can use the following delegate callback:
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
//1. If Out Target Image Has Been Detected Than Get The Corresponding Anchor
guard let currentImageAnchor = anchor as? ARImageAnchor else { return }
//2. Get The Targets Name
let name = currentImageAnchor.referenceImage.name!
//3. Get The Targets Width & Height
let width = currentImageAnchor.referenceImage.physicalSize.width
let height = currentImageAnchor.referenceImage.physicalSize.height
//4. Log The Reference Images Information
print("""
Image Name = \(name)
Image Width = \(width)
Image Height = \(height)
""")
}
Note that this code assumes that your images have a name which is set in the ARResources Asset Folder e.g:
You can then put logic within the callback or call another function which adds an SCNNode or SCNScene at the transform of the ARImageAnchor e.g:
//1. Create An SCNNode
let nodeHolder = SCNNode()
//2. Determine Which ImageTarget Has Been Detected
if name == "ImageOne"{
let nodeGeometry = SCNBox(width: 0.02, height: 0.02, length: 0.02, chamferRadius: 0)
nodeGeometry.firstMaterial?.diffuse.contents = UIColor.cyan
nodeHolder.geometry = nodeGeometry
}else if name == "ImageTwo"{
let nodeGeometry = SCNSphere(radius: 0.02)
nodeGeometry.firstMaterial?.diffuse.contents = UIColor.cyan
nodeHolder.geometry = nodeGeometry
}
//3. Add The SCNNode At The Position Of The Anchor
nodeHolder.position = SCNVector3(currentImageAnchor.transform.columns.3.x,
currentImageAnchor.transform.columns.3.y,
currentImageAnchor.transform.columns.3.z)
//4. Add It To The Scene
augmentedRealityView?.scene.rootNode.addChildNode(nodeHolder)