使用触摸移动 SceneKit 中的节点

Question

我正在尝试通过触摸移动 SceneKit 中的一个节点。我在这里使用代码：

我遇到的问题是每次启动 panGesture 时，我触摸的对象都会转到场景的左角以开始移动。从那个位置移动它并释放是可以的，只是在每次开始平移时，对象从左角重置的问题。如果我缩小，它会从这个新缩放级别的一角重置自身。

我的代码是：

func CGPointToSCNVector3(view: SCNView, depth: Float, point: CGPoint) -> SCNVector3 {
    let projectedOrigin = view.projectPoint(SCNVector3Make(0, 0, depth))
    let locationWithz   = SCNVector3Make(Float(point.x), Float(point.y), projectedOrigin.z)
    return view.unprojectPoint(locationWithz)
}
func dragObject(sender: UIPanGestureRecognizer){
    if(movingNow){
        let translation = sender.translationInView(sender.view!)
        var result : SCNVector3 = CGPointToSCNVector3(objectView, depth: tappedObjectNode.position.z, point: translation)
        tappedObjectNode.position = result
    }
    else{
        let hitResults = objectView.hitTest(sender.locationInView(objectView), options: nil)
        if hitResults.count > 0 {
            movingNow = true
        }
    }
    if(sender.state == UIGestureRecognizerState.Ended) {
    }
}

和

override func viewDidLoad() {
    super.viewDidLoad()
    let scnView = objectView
    scnView.backgroundColor = UIColor.whiteColor()
    scnView.autoenablesDefaultLighting = true
    scnView.allowsCameraControl = true

我通过这样做在调用 dragObject 之前暂时禁用 allowsCameraControl 的平移功能：

globalPanRecognizer = UIPanGestureRecognizer(target: self, 
    action:#selector(ViewController.dragObject(_:)))
objectView.addGestureRecognizer(globalPanRecognizer)

这些是第一次调用 CGPointToSCNVector3 时的值：

tappedObjectNode初始值：SCNVector3(x: 0.100000001, y: 0.100000001, z: 3.0)
projectedOrigin : SCNVector3(x: 261.613159, y: 285.530396, z: 0.949569583) - 这异常大
CGPointToSCNVector3 返回的值：SCNVector3(x: 1.03418088, y: 1.9734658, z: 4.64346933)

我玩过 CGPointToSCNVector3 的不同变体，但运气不好。这种行为的原因是什么？谢谢，

Answer 1

解决方案是将 sender.translationInView(sender.view!) 更改为 sender.translationInView(self.view!)

Answer 2

Swift 4.1 / Xcode 9.3 / iOS 11.3

// node that you want the user to drag
var tappedObjectNode = SCNNode()

// the SCNView
@IBOutlet weak var sceneView: SCNView!

// the scene
let scene = SCNScene()

//helper
func CGPointToSCNVector3(view: SCNView, depth: Float, point: CGPoint) -> SCNVector3 {
    let projectedOrigin = view.projectPoint(SCNVector3Make(0, 0, depth))
    let locationWithz   = SCNVector3Make(Float(point.x), Float(point.y), projectedOrigin.z)
    return view.unprojectPoint(locationWithz)
}

// gesture handler
var movingNow = false
@objc func dragObject(sender: UIPanGestureRecognizer){
if(movingNow){
        let translation = sender.translation(in: sender.view!)
        var result : SCNVector3 = CGPointToSCNVector3(view: sceneView, depth: tappedObjectNode.position.z, point: translation)    
        tappedObjectNode.position = result
    } else {
        // view is the view containing the sceneView
        let hitResults = sceneView.hitTest(sender.location(in: view), options: nil)
        if hitResults.count > 0 {
            movingNow = true
        }
    }
}


// in viewDidLoad
sceneView.scene = scene

let panner = UIPanGestureRecognizer(target: self, action: #selector(dragObject(sender:)))
sceneView.addGestureRecognizer(panner)

使用触摸移动 SceneKit 中的节点

Moving a node in SceneKit using touch

ios

scenekit

swift