Unable to draw boundBox while detecting object with arkit2 - ios

Question

I am developing iOS app which will highlight objects ( not specific one that we do with .arobject files) with outlined box in real world. Idea is to implement only boundBox drawing from this documentation / example.
Got some idea from this stackoverflow answer but still unable to draw outlined boundBox to scanned object.
// Declaration
let configuration = ARObjectScanningConfiguration()
let augmentedRealitySession = ARSession()
// viewWillAppear(_ animated: Bool)
configuration.planeDetection = .horizontal
sceneView.session.run(configuration, options: .resetTracking)
// renderer
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
//print("\(self.detectionObjects.debugDescription)")
guard let objectAnchor = anchor as? ARObjectAnchor else { return }
//2. Create A Bounding Box Around Our Object
let scale = CGFloat(objectAnchor.referenceObject.scale.x)
let boundingBoxNode = BlackMirrorzBoundingBox(points: objectAnchor.referenceObject.rawFeaturePoints.points, scale: scale)
node.addChildNode(boundingBoxNode)
}
// BlackMirrorzBoundingBox class
init(points: [float3], scale: CGFloat, color: UIColor = .cyan) {
super.init()
var localMin = float3(repeating: Float.greatestFiniteMagnitude)
var localMax = float3(repeating: -Float.greatestFiniteMagnitude)
for point in points {
localMin = min(localMin, point)
localMax = max(localMax, point)
}
self.simdPosition += (localMax + localMin) / 2
let extent = localMax - localMin
let wireFrame = SCNNode()
let box = SCNBox(width: CGFloat(extent.x), height: CGFloat(extent.y), length: CGFloat(extent.z), chamferRadius: 0)
box.firstMaterial?.diffuse.contents = color
box.firstMaterial?.isDoubleSided = true
wireFrame.geometry = box
setupShaderOnGeometry(box)
self.addChildNode(wireFrame)
}
func setupShaderOnGeometry(_ geometry: SCNBox) {
guard let path = Bundle.main.path(forResource: "wireframe_shader", ofType: "metal", inDirectory: "art.scnassets"),
let shader = try? String(contentsOfFile: path, encoding: .utf8) else {
return
}
geometry.firstMaterial?.shaderModifiers = [.surface: shader]
}
With above logic i am getting box only on plane surface instead of outlined box as in this picture.

Answer 1

You are probably missing the wireframe_shader shader file.
Make sure you add it to the project into the art.scnassets, then try to reload the app.
You can find a similar shader in this repository, don't forget to change the name of the shader file or the resource name in the code.