只能移动场景中放置的最后一个对象

由于您没有发布任何代码,因此很难提供准确的答案。

然而,为了跟踪当前 SCNNode 您希望使用,当您加载模型等时,可以将其存储为变量,例如:

var currentNode: SCNNode!

您也可以使用 name 属性,以保留对其更具体的引用。

下面是一个这样做的示例:

/// Example Of Loading An SCNScene & Setting It As The Current Node
func loadModel(){

        let modelPath = "Character.scn"

        //1. Get The Reference To Our SCNScene & Get The Model Root Node
        guard let model = SCNScene(named: modelPath),
            let modelObject = model.rootNode.childNode(withName: "Root", recursively: false) else { return }

        //2. Scale It
        modelObject.scale = SCNVector3(0.4, 0.4, 0.4)

        //3. Add It To The Scene & Position It 1.5m Away From The Camera
        augmentedRealityView.scene.rootNode.addChildNode(modelObject)
        modelObject.position = SCNVector3(0, 0, -1.5)

        //4. Set It As The Current Node & Assign A Name
        currentNode = modelObject
        currentNode.name = "Character"

 }

您还可以使用 SCNHitTest 其中:

沿指定的光线查找SCNGeometry对象。对于每个 光线和几何体之间的交点,SceneKit创建 点击测试结果以提供有关SCNNode对象和 包含几何图形和交叉点的位置 几何曲面。

这可以用来区分哪些节点被击中,例如:

/// Detects A Tap On An SCNNode
///
/// - Parameter gesture: UITapGestureRecognizer
@objc func detectTap(_ gesture: UITapGestureRecognizer){

    //1. Get The Current Touch Point
    let currentTouchPoint = gesture.location(in: self.augmentedRealityView)

    //2a. Perform An SCNHitTest To Detect If An SCNNode Has Been Touched
    guard let nodeHitTest = self.augmentedRealityView.hitTest(currentTouchPoint, options: nil).first else { return }

    if nodeHitTest.node == currentNode{
        print("The Current Node Has Been Touched")
    }

    //Or To See Which Node Has Been Touched
    if nodeHitTest.node.name == "The Model"{
        print("The Model Has Been Touched")
    }
}

处理此问题的另一种方法是向视图中添加UITapgestureRecognitor,并根据结果启用交互,例如以这种方式设置currentNode,例如:

/// Detects A Tap On An SCNNode & Sets It As The Current Node
///
/// - Parameter gesture: UITapGestureRecognizer
@objc func detectTap(_ gesture: UITapGestureRecognizer){

    //1. Get The Current Touch Point
    let currentTouchPoint = gesture.location(in: self.augmentedRealityView)

    //2a. Perform An SCNHitTest To Detect If An SCNNode Has Been Touched
    guard let nodeHitTest = self.augmentedRealityView.hitTest(currentTouchPoint, options: nil).first else { return }

    //2b. Set It As The Current Node
    currentNode = nodeHitTest.node
}

然后,您可以应用逻辑来确保 currentNode 移动等:

/// Moves An SCNNode
///
/// - Parameter gesture: UIPanGestureRecognizer
@objc func moveNode(_ gesture: UIPanGestureRecognizer) {

    //1. Get The Current Touch Point
    let currentTouchPoint = gesture.location(in: self.augmentedRealityView)

    //2. If The Gesture State Has Begun Perform A Hit Test To Get The SCNNode At The Touch Location
    if gesture.state == .began{

        //2a. Perform An SCNHitTest To Detect If An SCNNode Has Been Touched
        guard let nodeHitTest = self.augmentedRealityView.hitTest(currentTouchPoint, options: nil).first else { return }

        //2b. Get The SCNNode Result
        if nodeHitTest.node == currentNode{

            //3a. If The Gesture State Has Changed Then Perform An ARSCNHitTest To Detect Any Existing Planes
            if gesture.state == .changed{

                //3b. Get The Next Feature Point Etc
                guard let hitTest = self.augmentedRealityView.hitTest(currentTouchPoint, types: .existingPlane).first else { return }

                //3c. Convert To World Coordinates
                let worldTransform = hitTest.worldTransform

                //3d. Set The New Position
                let newPosition = SCNVector3(worldTransform.columns.3.x, worldTransform.columns.3.y, worldTransform.columns.3.z)

                //3e. Apply To The Node
                currentNode.simdPosition = float3(newPosition.x, newPosition.y, newPosition.z)

            }

        }
    }
}

这应该足以为您指明正确的方向。。。