如何使用平移手勢識別器移動ARSCNView中的節點？

Question

我在viewDidLoad

let scene = SCNScene(named: "funModel")! 
myNode = scene.rootNode.childNode(withName: "blah")! 
myNode.position = SCNVector3Make(0, 0, -1) 
sceneView.scene = scene 
let pan = UIPanGestureRecognizer(target: self, action: #selector(panGesture(recognizer:))) 
view.addGestureRecognizer(pan) 

下面的代碼，然後從another SO answer在panGesture下面的代碼，但它不工作。節點只是看起來像0,0,0。我只是想能夠在屏幕上拖動節點。

let projectedOrigin = sceneView.projectPoint(SCNVector3Zero) 
let vp = recognizer.location(in: sceneView) 
let vpWithZ = SCNVector3(x: Float(vp.x), y: Float(vp.y), z: Float(projectedOrigin.z)) 
let worldPoint = sceneView.unprojectPoint(vpWithZ) 
myNode.position = worldPoint 

Answer 1

你首先需要得到UIPanGestureRecognizer位置則hitTest點（在UIPanGestureRecognizer功能），如：

let point = pan.location(in: scene) 
let result = scene.hitTest(point, types: .featurePoint) 
let resultPoint = result.first 

現在這個新的世界的觀點是：

let vpWithZ = SCNVector3(x: Float(resultPoint.worldTransform.columns.3.x), y: Float(resultPoint.worldTransform.columns.3.y), z: Float(projectedOrigin.z)) 

希望它幫助。