I have an ARKit application that detects a myriad of objects and then places 3d objects above them. I would like to change the text of the 3d object displayed above the detected objects, but can't figure out how to perform x function if y object is detected.
My collection of AR scans / objects is in a group called "gallery" and my code looks like this:
class ViewController: UIViewController, ARSCNViewDelegate {
@IBOutlet var sceneView: ARSCNView!
var arrowAnchor:ARAnchor?
override func viewDidLoad() {
super.viewDidLoad()
// Set the view's delegate
sceneView.delegate = self
sceneView.showsStatistics = true
sceneView.autoenablesDefaultLighting = true
sceneView.debugOptions = [ARSCNDebugOptions.showFeaturePoints]
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//Create ARWorldTrackingConfiguration object and load your garrey asset group.
//You can add multiple ARObject file into ar asset group,
let configuration = ARWorldTrackingConfiguration()
guard let referenceObjects = ARReferenceObject.referenceObjects(inGroupNamed: "gallery", bundle: nil) else {
fatalError("Missing expected asset catalog resources.")
}
configuration.detectionObjects = referenceObjects
sceneView.session.run(configuration)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
// Pause the view's session
sceneView.session.pause()
}
func session(_ session: ARSession, didFailWithError error: Error) {
// Present an error message to the user
}
func sessionWasInterrupted(_ session: ARSession) {
// Inform the user that the session has been interrupted, for example, by presenting an overlay
}
func sessionInterruptionEnded(_ session: ARSession) {
// Reset tracking and/or remove existing anchors if consistent tracking is required
}
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
if let objectAnchor = anchor as? ARObjectAnchor {
let translation = objectAnchor.transform.columns.3
let pos = float3(translation.x, translation.y, translation.z)
let nodeArrow = getArrowNode()
nodeArrow.position = SCNVector3(pos)
nodeArrow.constraints = [SCNBillboardConstraint()]
sceneView.scene.rootNode.addChildNode(nodeArrow)
let text = SCNText(string: "Asset", extrusionDepth: 1)
let material = SCNMaterial()
material.diffuse.contents = UIColor.white
text.materials = [material]
let node = SCNNode()
let pos2 = float3(translation.x-0.01, translation.y+0.22, translation.z-0.0)
node.position = SCNVector3(pos2)
node.scale = SCNVector3(x: 0.003, y: 0.003, z: 0.003)
node.geometry = text
node.constraints = [SCNBillboardConstraint()]
sceneView.scene.rootNode.addChildNode(node)
}
}
func getArrowNode() -> SCNNode {
let sceneURL = Bundle.main.url(forResource: "arrow_yellow", withExtension: "scn", subdirectory: "art.scnassets")!
let referenceNode = SCNReferenceNode(url: sceneURL)!
referenceNode.load()
return referenceNode
}
func getTextNode() -> SCNNode {
let sceneURL = Bundle.main.url(forResource: "text", withExtension: "scn", subdirectory: "art.scnassets")!
let referenceNode = SCNReferenceNode(url: sceneURL)!
referenceNode.load()
return referenceNode
}
}
How can have certain code blocks execute depending on which reference object was detected?
This little magic incantation does exactly what I needed:
let objectName = objectAnchor.referenceObject.name
I used the code like this:
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
if let objectAnchor = anchor as? ARObjectAnchor {
let objectName = objectAnchor.referenceObject.name
let translation = objectAnchor.transform.columns.3
let pos = float3(translation.x, translation.y, translation.z)
let nodeArrow = getArrowNode()
nodeArrow.position = SCNVector3(pos)
nodeArrow.constraints = [SCNBillboardConstraint()]
sceneView.scene.rootNode.addChildNode(nodeArrow)
let text = SCNText(string: objectName, extrusionDepth: 1)
let material = SCNMaterial()
material.diffuse.contents = UIColor.white
text.materials = [material]
let node = SCNNode()
let pos2 = float3(translation.x-0.01, translation.y+0.22, translation.z-0.0)
node.position = SCNVector3(pos2)
node.scale = SCNVector3(x: 0.003, y: 0.003, z: 0.003)
node.geometry = text
node.constraints = [SCNBillboardConstraint()]
sceneView.scene.rootNode.addChildNode(node)
}
}