Swift – ARMeshAnchor to Data conversion

Question

In my project I'm trying to store an ARMeshAnchor into UserdDefaluts converting it to Data. I'm unable to find a solution.

This one of my errors Instance method encode(_:forKey:) requires that ARMeshAnchor conform to Encodable.

Maybe it is better to convert them to an SCNNode and try to convert the node to Data?

Thanks

Answer 1

For this you should use NSKeyedArchiver class and your code might look like this:

@IBOutlet var arView: ARView!

fileprivate func convertMeshAnchors() -> UserDefaults {

    guard let frame = arView.session.currentFrame else { return }
    let meshAnchors = frame.anchors.compactMap { $0 as? ARMeshAnchor }

    let data = try! NSKeyedArchiver.archivedData(withRootObject: meshAnchors,
                                          requiringSecureCoding: false)

    let savedAnchors = UserDefaults.standard
    savedAnchors.set(data, forKey: "MeshAnchors")
    savedAnchors.synchronize()

    return savedAnchors
}

And remember in RealityKit there's also a scene object where anchors' collection is located:

arView.scene.anchors