ARKit（Xcode）中 ARSCNView 上的滑块

Question

所以我是 Swift、Xcode 和 Arkit 的新手。 我使用 Xcode 9.2

我想构建一个简单的应用程序，当在屏幕上点击一个对象时，它会放置到它检测到一个平面或点的位置。

我启动了 Xcode，并将这段简短的代码写入了基本示例中，当您打开 scenekit 时就在该示例中。 代码如下所示：

import UIKit
import SceneKit
import ARKit

class ViewController: UIViewController, ARSCNViewDelegate {
    @IBOutlet var sceneView: ARSCNView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set the view's delegate
        sceneView.delegate = self

        // Show statistics such as fps and timing information
        sceneView.showsStatistics = true

        // Create a new scene
        let scene = SCNScene(named: "art.scnassets/ship.scn")!

        // Set the scene to the view
        sceneView.scene = scene
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // Create a session configuration
        let configuration = ARWorldTrackingConfiguration()

        // Run the view's session
        sceneView.session.run(configuration)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        // Pause the view's session
        sceneView.session.pause()
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else {return}
        let result = sceneView.hitTest(touch.location(in: sceneView), types: [ARHitTestResult.ResultType.featurePoint])
        guard let hitResult = result.last else {return}
        let hitTransform = SCNMatrix4.init(hitResult.worldTransform)
        let hitVector = SCNVector3Make(hitTransform.m41,hitTransform.m42,hitTransform.m43)
        createBall(position: hitVector)
    }

    func createBall(position: SCNVector3){
        var ballShape = SCNSphere(radius: 0.01)
        var ballNode = SCNNode(geometry: ballShape)

        ballNode.position = position

        sceneView.scene.rootNode.addChildNode(ballNode)
    }

    // MARK: - ARSCNViewDelegate

    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
    }
}

我插入了这个相关部分：

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else {return}
        let result = sceneView.hitTest(touch.location(in: sceneView), types: [ARHitTestResult.ResultType.featurePoint])
        guard let hitResult = result.last else {return}
        let hitTransform = SCNMatrix4.init(hitResult.worldTransform)
        let hitVector = SCNVector3Make(hitTransform.m41,hitTransform.m42,hitTransform.m43)
        createBall(position: hitVector)
    }

    func createBall(position: SCNVector3){
        var ballShape = SCNSphere(radius: 0.01)
        var ballNode = SCNNode(geometry: ballShape)

        ballNode.position = position

        sceneView.scene.rootNode.addChildNode(ballNode)
    }

这个应用程序运行良好。每次我点击屏幕时，它都会放置球。 现在我想向 Main.Storyboard 添加一个滑块，以更改要放置的球的大小值。 Main.Storyboard 如下所示：

当我在情节提要屏幕上拖动滑块时，滑块不会添加到场景中，而是将 ARSCNView 放置到全尺寸。然后它看起来像这样：

我需要做什么才能将滑块放在视图上？这是否适用于其他 UI 元素？这甚至可能吗？它是如何工作的。这可能很简单，但这是我第一次在 Xcode 中编码。

Answer 1

您不能将 UI 控件拖放到 ARSCNView。 （它不应该托管子视图）你需要

1. 拖动 UIView 到你的场景，
2. 然后将ARSCNView拖到它上面，
3. 添加约束（例如，上、下、左、右 = 0），
4. 将您的 ARSCNView 链接到 sceneView
5. 添加您的滑块。确保滑块在 ARSCNView 上方（层次结构中较低），否则将隐藏在后面。

Answer 2

以编程方式在快速操场上缩放球的完整编码解决方案。

import ARKit
import UIKit
import SceneKit
import PlaygroundSupport


// Main ARKIT ViewController
class ViewController : UIViewController, ARSCNViewDelegate, ARSessionDelegate {

    var ballNode: SCNNode!
    @IBOutlet var sceneView: ARSCNView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // set the views delegate
        sceneView.delegate = self as! ARSCNViewDelegate
       // show statistics such as fps and timing information
       sceneView.showsStatistics = true
       // Create a new scene 
       sceneView.scene.rootNode
       // Add ligthing
       sceneView.autoenablesDefaultLighting = true

        // sphere geometry
       let sphere = SCNSphere(radius: 0.1)

      //Create Node object
      ballNode = SCNNode(geometry: sphere)
        // position node in scene
     ballNode.position = SCNVector3(x: 0, y:0, z: -1)

     //  add new node to root node
     self.sceneView.scene.rootNode.addChildNode(ballNode)

     // Add an scaleSlider button
     weak var scaleSlider: UISlider! {
         didSet {
            scaleSlider.transform =  CGAffineTransform(rotationAngle: -CGFloat.pi/2)
        }
     }
     scaleSlider = UISlider()
     scaleSlider.addTarget(self, action: #selector(updateScaleWithSlider(_:)), for: .touchUpInside)
     scaleSlider.minimumValue = 0
     scaleSlider.maximumValue = 10
        // add scaleSlider to view
    sceneView.addSubview(scaleSlider)

    // Auto Layout
    scaleSlider.translatesAutoresizingMaskIntoConstraints = true
  }

 override func loadView() {

    sceneView = ARSCNView(frame:CGRect(x: 0.0, y: 0.0, width: 500.0, height: 600.0))
    // Set the view's delegate
    sceneView.delegate = self 

    let config = ARWorldTrackingConfiguration()
    config.planeDetection = .horizontal

    // Now we'll get messages when planes were detected...
    sceneView.session.delegate = self

    self.view = sceneView
    sceneView.session.run(config)

 }

 func scaleNode(value: Float) {
    SCNTransaction.begin()
    SCNTransaction.animationDuration = 1
    ballNode.scale = SCNVector3(value, value, value)
    SCNTransaction.commit()
 }

@IBAction func updateScaleWithSlider(_ sender: UISlider) {
    guard let slider = sender as? UISlider else { return }
    scaleNode(value: slider.value)
 }

}
PlaygroundPage.current.liveView = ViewController()
PlaygroundPage.current.needsIndefiniteExecution = true