swift – 如何使用ARKit检测触摸并显示新的SCNPlane？

首先,您正在创建一个您已声明的全局变量：

var cake_1_PlaneNode : SCNNode? = nil

但是,在yourDelegate回调中为cake_1_PlaneNode使用本地变量和全局变量：

let cake_1_PlaneNode = SCNNode(geometry: cake_1_Plane)
self.cake_1_PlaneNode = cake_1_PlaneNode

这应该只是这样读：

self.cake_1_PlaneNode = SCNNode(geometry: cake_1_Plane)

其次,您将cake_1_PlaneNode添加到ARSCNView的rootNode而不是您检测到的ARImageAnchor,这可能是您不想做的事情,因为当检测到ARAnchor时：

You can provide visual content for the anchor by attaching geometry
(or other SceneKit features) to this node or by adding child nodes.

因此,这种方法(除非你真的想这样做)是不必要的.

剩下的问题在于你的cake_1函数本身.

首先,您实际上并没有将planeNodee添加到sceneHierachy中.

由于您尚未指定是否应将新初始化的planeNode直接添加到ARSCNView或作为cake_1_planeNode的childNode,因此您的函数应包括以下内容之一：

self.sceneView.scene.rootNode.addChildNode(planeNodee)    
self.cake_1_planeNode.addChildNode(planeNodee)

此外,可能还没有必要旋转您的planeNodee,因为默认情况下SCNPlane是垂直渲染的.

由于您没有规定放置内容的位置,因此可能不需要使用-.pi / 2,因为这可能使其几乎看不见肉眼.

另一个问题也可能导致您在实际添加节点时没有看到您的节点是Z位置.

如果您在同一位置设置2个节点,您可能会遇到一个称为Z-fighting的问题(您可以阅读更多关于here的信息).因此,您可能应该在添加节点时稍微向前移动添加的节点,例如SCNVector3(0,0.001)来解释这一点.

基于所有这些要点,我在下面提供了一个完整的工作和评论示例：

import UIKit
import ARKit

//-------------------------
//MARK: - ARSCNViewDelegate
//-------------------------

extension ViewController: ARSCNViewDelegate {

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

        //1. Check We Have An ARImageAnchor,Then Get It's Reference Image & Name
        guard let imageAnchor = anchor as? ARImageAnchor else { return }

        let detectedTarget = imageAnchor.referenceImage

        guard let detectedTargetName = detectedTarget.name  else { return }

        //2. If We Have Detected Our Virtual Menu Then Add The CakeOnePlane
        if detectedTargetName == "cakeMenu" {

            let cakeOnePlaneGeometry = SCNPlane(width: 0.045,height: 0.045)
            cakeOnePlaneGeometry.firstMaterial?.diffuse.contents = UIColor.cyan
            cakeOnePlaneGeometry.cornerRadius = 0.01

            let cakeOnPlaneNode = SCNNode(geometry: cakeOnePlaneGeometry)
            cakeOnPlaneNode.eulerAngles.x = -.pi/2

            //3. To Allow Us To Easily Keep Track Our Our Currently Added Node We Will Assign It A Unique Name
            cakeOnPlaneNode.name = "Strawberry Cake"

            node.addChildNode(cakeOnPlaneNode)
            cakeOnPlaneNode.runAction(SCNAction.moveBy(x: 0.15,duration: 0.75))


        }
    }
}

class ViewController: UIViewController {

    @IBOutlet var augmentedRealityView: ARSCNView!
    let augmentedRealitySession = ARSession()
    let configuration = ARWorldTrackingConfiguration()

    //------------------
    //MARK: - Life Cycle
    //------------------

    override func viewDidLoad() {
        super.viewDidLoad()

        setupARSession()
    }


    //-----------------
    //MARK: - ARSession
    //-----------------

    /// Runs The ARSession
    func setupARSession(){

        //1. Load Our Detection Images
        guard let detectionImages = ARReferenceImage.referenceImages(inGroupNamed: "AR Resources",bundle: nil) else { return }

        //2. Configure & Run Our ARSession
        augmentedRealityView.session = augmentedRealitySession
        augmentedRealityView.delegate = self
        configuration.detectionImages = detectionImages
        augmentedRealitySession.run(configuration,options: [.resetTracking,.removeExistingAnchors])

    }

    //--------------------
    //MARK: - Interaction
    //--------------------

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

        //1. Get The Current Touch Location & Perform An ARSCNHitTest To Check For Any Hit SCNNode's
        guard let currentTouchLocation = touches.first?.location(in: self.augmentedRealityView),let hitTestNode = self.augmentedRealityView.hitTest(currentTouchLocation,options: nil).first?.node else { return }

        //2. If We Have Hit Our Strawberry Cake Then We Call Our makeCakeOnNode Function
        if let cakeID = hitTestNode.name,cakeID == "Strawberry Cake"{

            makeCakeOnNode(hitTestNode)

        }
    }


    /// Adds An SCNPlane To A Detected Cake Target
    ///
    /// - Parameter node: SCNNode
    func makeCakeOnNode(_ node: SCNNode){

        let planeGeometry = SCNPlane(width: 0.15,height: 0.15)
        planeGeometry.firstMaterial?.diffuse.contents = UIColor.black.withAlphaComponent(0.75)

        let planeNode = SCNNode(geometry: planeGeometry)
        planeNode.position = SCNVector3(0,0.001)
        planeNode.runAction(SCNAction.moveBy(x: 0.21,duration: 0))
        node.addChildNode(planeNode)

    }
}

这在我的设备上产生以下内容：

对于您的信息,这似乎表明您放置内容的计算是关闭的(除非当然这是期望的结果).

正如您所看到的,所有内容都正确呈现,但是这些内容的间距非常大,因此您可能需要稍微平移设备,以便在进一步测试和开发时看到它们.

希望能帮助到你…