SceneKit，object 不移动并对施加在 childNode 上的力做出反应

Question

我正在尝试使用 ARKit 和 SceneKit 驾驶我的无人机。

这里我的scn文件结构和我在游戏开始时加载无人机的方法。

func loadDrone(){
        guard let scene = SCNScene(named: "Model.scnassets/Drone.scn") else {fatalError()}
        guard let heli = scene.rootNode.childNode(withName: "helicopter", recursively: false) else {fatalError()}
        heli.name = "elicottero"
        guard let blade1Node = heli.childNode(withName: "Rotor_R_2", recursively: true) else {fatalError()}
        guard let blade2Node = heli.childNode(withName: "Rotor_L_2", recursively: true) else {fatalError()}
        guard let rotorR = blade1Node.childNode(withName: "Rotor_R", recursively: true) else {fatalError()}
        guard let rotorL = blade2Node.childNode(withName: "Rotor_L", recursively: true) else {fatalError()}
        rotorRGen = rotorR
        rotorLGen = rotorL
        blade1NodeGen = blade1Node
        blade2NodeGen = blade2Node
        // apply material
        let bodyMaterial = SCNMaterial()
        bodyMaterial.diffuse.contents =  UIImage(named: "Flying drone_col")
        heli.geometry?.materials = [bodyMaterial]
        scene.rootNode.geometry?.materials = [bodyMaterial]
        // rotation blade
        let rotate = SCNAction.rotateBy(x: 0, y: 200, z: 0, duration: 0.5)
        let moveSequence = SCNAction.sequence([rotate])
        let moveLoop = SCNAction.repeatForever(moveSequence)
        rotorL.runAction(moveLoop)
        rotorR.runAction(moveLoop)
        let shape = SCNPhysicsShape(node: heli, options: nil)
        let body = SCNPhysicsBody(type: .dynamic, shape: shape)
        heli.physicsBody = body
        heli.physicsBody?.mass = 1
        heli.physicsBody?.categoryBitMask = BodyType.drone.rawValue // cosa e
        heli.physicsBody?.collisionBitMask = BodyType.airport.rawValue | BodyType.ball.rawValue// con cosa deve collidere
        heli.physicsBody?.contactTestBitMask = BodyType.airport.rawValue | BodyType.ball.rawValue  // with what need to report contact
        
     
        self.drone = heli


    }

现在这里的问题：

使用以下方法我施加力使其飞行，这个力施加在无人机的质心上

用这种方法，我的无人机飞得很完美。

 func applyForce(powerApply: Double, isHovering: Bool, gravity : SCNVector3) {
   
        let nodo = arrayDrone[0] // load the first drone in the scene
        
        if isHovering == true { // use to hold the altitude
           
            let grav = SCNVector3(gravity.x, abs(gravity.y), gravity.z)
            
            nodo.physicsBody?.applyForce(grav, asImpulse: false)
        } else {
// APPLY FORCE HERE
            print("apply power  \(powerApply)")
            let force = SCNVector3(0, powerApply, 0)
            
            nodo.physicsBody?.applyForce(force, asImpulse: false)
        }
    }

现在由于无人机有 2 个引擎，我想将作用在 2 个转子之一上的力更逼真.. 但以下方法不正确。

我正在尝试将力施加到左转子..

func applyForceToDrone(powerApply: Double, isHovering: Bool, gravity : SCNVector3) {
   
        let nodo = arrayDrone[0] // load the first drone in the scene
        guard let lhBlade = nodo.childNode(withName: "Rotor_L_2", recursively: true) else {fatalError()}
        guard let rotorL = lhBlade.childNode(withName: "Rotor_L", recursively: true) else {fatalError()}
        
        print("Got rotorL named:\(String(describing: rotorL.name))")
        if isHovering == true {
            print("x gravity = \(gravity.x), \(gravity.y) \(gravity.z)")
            let force = SCNVector3(gravity.x, abs(gravity.y), gravity.z)
            
            rotorL.physicsBody?.applyForce(force, asImpulse: false)
        } else {
// HERE... why I can not apply force to the LHRotor of the drone
            print("apply power  \(powerApply)")
            let force = SCNVector3(0, powerApply, 0)
            
           
            rotorL.physicsBody?.applyForce(force, asImpulse: false)
        }
    }

如何对子节点施加力？ 如果我对孩子施加力量，他的父母也应该受到影响吗？ 我做错了什么？