检测在 arkit 上点击了哪个平面

Question

我正在使用 ARKit，我在一个场景中有多个平面节点 (SCNPlanes)。我想使用 hittest 来检测飞机上的触摸，但我不确定如何检测哪架飞机被点击了。每架飞机都有一个与我的图像识别代码相关联的名称。这是我的 TouchesBegan 函数：

//detects taps on transparent planes created by reference images
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        let touch = touches.first as! UITouch
        if(touch.view == self.sceneView){
            let viewTouchLocation:CGPoint = touch.location(in: sceneView)
            guard let result = sceneView.hitTest(viewTouchLocation, options: nil).first else {
                return
            }
            print("results", "\(result)")
            let touchPlaneNode = planeNode
            if touchPlaneNode == result.node {
                print("tapped on a match, but which plane did I tap on?")
            }

        }
    }

谢谢！

Answer 1

假设我已经正确阅读了你的问题，开始的一个好方法是将 ARPlaneAnchor 及其关联的 SCNNode 存储在字典中，例如：

    var planes = [ARPlaneAnchor: PlaneNode]()

我的 'Plane Node' 值是自定义 SCNNode，但您可以存储任何您喜欢的节点。

然后将在以下 ARSCNView 委托方法中创建此引用：

 func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

        //1. Check The We Have An ARPlane Anchor
        guard let planeAnchor = anchor as? ARPlaneAnchor else { return }

        //2. Create Our Plane Node
        let planeNode = PlaneNode(anchor: planeAnchor, node: node, image: true, identifier: planes.keys.count, opacity: 1)

        //3. Store A Reference To It
        planes[planeAnchor] = planeNode


}

然后在 Touches Began 中你可以这样做：

   override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    /*
     1. Get The Current Touch Location
     2. Check That We Have Touched A Valid Node
     3. Check That Our Touched Object Is An ARPlane Anchor
     4. Determine If It Is One That Has Been Stored
     5. Get It's Name
     */

    guard let touchLocation = touches.first?.location(in: augmentedRealityView),
        let hitTest = augmentedRealityView.hitTest(touchLocation, types: .existingPlaneUsingExtent).first,
        let planeAnchor = hitTest.anchor as? ARPlaneAnchor,
        let detectedPlane = self.planes[planeAnchor],
        let nodeID = detectedPlane.name
        else {
             //No Valid Plane Has Been Detected
            return

    }

    print(nodeID)


}

在touchesBegan方法中，augmentedRealityView引用了一个设置为IBOutlet的ARSCNView。

我的 PlaneNode Class 看起来像这样（您需要添加自己的图像，在我的 Assets Bundle 中称为：defaultGrid）：

class PlaneNode: SCNNode {

let DEFAULT_IMAGE: String = "defaultGrid"
let NAME: String = "PlaneNode"
var planeGeometry: SCNPlane
var planeAnchor: ARPlaneAnchor

var widthInfo: String!
var heightInfo: String!
var alignmentInfo: String!

//---------------
//MARK: LifeCycle
//---------------

/// Inititialization
///
/// - Parameters:
///   - anchor: ARPlaneAnchor
///   - node: SCNNode
///   - node: Bool
init(anchor: ARPlaneAnchor, node: SCNNode, image: Bool, identifier: Int, opacity: CGFloat = 0.25){

    self.planeAnchor = anchor

    self.planeGeometry = SCNPlane(width: CGFloat(anchor.extent.x), height: CGFloat(anchor.extent.z))
    let planeNode = SCNNode(geometry: planeGeometry)

    super.init()

    if image{

        let planeMaterial = SCNMaterial()
        planeMaterial.diffuse.contents = UIImage(named: DEFAULT_IMAGE)

        self.planeGeometry.materials = [planeMaterial]
    }

    planeNode.simdPosition = float3(self.planeAnchor.center.x, 0, self.planeAnchor.center.z)
    planeNode.eulerAngles.x = -.pi / 2
    planeNode.opacity = opacity

    node.addChildNode(planeNode)
    node.name = "\(NAME) \(identifier)"

}

required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") }

deinit {
    #if DEBUG
    print("Plane Node Deinitialized")
    #endif
}

/// Updates The Size Of The Plane As & When The ARPlaneAnchor Has Been Updated
///
/// - Parameter anchor: ARPlaneAnchor
func update(_ anchor: ARPlaneAnchor) {

    self.planeAnchor = anchor

    self.planeGeometry.width = CGFloat(anchor.extent.x)
    self.planeGeometry.height = CGFloat(anchor.extent.z)

    self.position = SCNVector3Make(anchor.center.x, 0.01, anchor.center.z)

    returnPlaneInfo()
}

//-----------------------
//MARK: Plane Information
//-----------------------

/// Returns The Size Of The ARPlaneAnchor & Its Alignment
func returnPlaneInfo(){

    let widthOfPlane = self.planeAnchor.extent.x
    let heightOfPlane = self.planeAnchor.extent.z

    var planeAlignment: String!

    switch planeAnchor.alignment {

    case .horizontal:
        planeAlignment = "Horizontal"
    case .vertical:
        planeAlignment = "Vertical"
    }

    #if DEBUG
    print("""
        Width Of Plane =  \(String(format: "%.2fm", widthOfPlane))
        Height Of Plane =  \(String(format: "%.2fm", heightOfPlane))
        Plane Alignment = \(planeAlignment)
        """)
    #endif

    self.widthInfo = String(format: "%.2fm", widthOfPlane)
    self.heightInfo = String(format: "%.2fm", heightOfPlane)
    self.alignmentInfo = planeAlignment
  }

}

检测在 arkit 上点击了哪个平面

detect which plane is tapped on arkit

ios

scenekit

arkit