How to get current SCNnode position after apply force

Question

I use the following method to apply a constant force to my SCNnode in the scene,

 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 rhBlade = nodo.childNode(withName: "Rotor_R_2", recursively: true) else {fatalError()}
        if isHovering == true {
            print("x gravity = \(gravity.x), \(gravity.y) \(gravity.z)")
            let force = SCNVector3(gravity.x, abs(gravity.y), gravity.z)

            nodo.physicsBody?.applyForce(force, asImpulse: false)
        } else {
            print("apply power  \(powerApply)")
            let positionBladeLH = lhBlade.position
            let positionBladeRH = rhBlade.position
            let force = SCNVector3(0, powerApply, 0)
            nodo.physicsBody?.applyForce(force, at: positionBladeLH, asImpulse: false)
            nodo.physicsBody?.applyForce(force, at: positionBladeRH, asImpulse: false)
            
            let alt = nodo.position.y // position is wrong ... is always the starting position
            print(alt)
        }
    }

I use than this func in the render method to fly my drone.

func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {}

i want to read the current position of the node every time the force is applied.

How can I get the update position while the render is applying the force.

I tried with :

let alt = nodo.position.y

but it always gave me the starting position of the node and not the one after the force is applied.

Thanks

ZAY ZAY · Accepted Answer · 2021-02-19T11:05:22

use the node's presentation object like so:

instead of

nodo.position.y

use

nodo.presentation.position.y // local space

or

nodo.presentation.worldPosition.y // world space

How to get current SCNnode position after apply force

1 Answers