Btukfyl

I'm trying to animate between two camera positions using the point of view node.

I want the animation to mimic the animation I get when I click and drag the orbit arc ball camera controller, which is a very short route most of the time.

As you can see in the movie below, the animation looks weird. It takes big detours. Sometimes out of the viewport.

Is it a gimbal lock situation? I get the same results whether I'm using rotation, eulerAngles or just set the transform. You can see my various attempts commented out in the code below

Here's the entire code :

import Cocoa

import SceneKit

class ViewController: NSViewController {



@IBOutlet weak var scnView: SCNView!

@IBOutlet weak var button: NSButton!



var secondaryPov : SCNNode!



var phoneNode : SCNNode!



var destination : SCNNode!



override func viewDidLoad() {

    super.viewDidLoad()



    guard let scn = SCNScene(named: "TestScene.scnassets/TestScene.scn") else {

        print("couldnt load the scene")

        fatalError()

    }



    scnView.scene = scn



    phoneNode = scn.rootNode.childNode(withName: "box", recursively: true)



    scnView.allowsCameraControl = true

    scnView.defaultCameraController.interactionMode = .orbitArcball



    print(scnView.pointOfView)

}



@IBAction func button(_ sender: Any) {

    print("bushed")

    print("point of view is now ")

    print(scnView.pointOfView)



    destination = SCNNode()

    destination.position = scnView.pointOfView!.position

    destination.rotation = scnView.pointOfView!.rotation



}



@IBAction func play(_ sender: Any) {

    let pov = scnView.pointOfView!



    SCNTransaction.begin()

    SCNTransaction.animationDuration = 3

    pov.transform = destination.transform

    SCNTransaction.commit()





    // A few other things I've tried





    // Also tried this. Rotation still weird, and I don't want to lock the object in the middle

    //        let lookAt = SCNLookAtConstraint(target: phoneNode)

    //        lookAt.isGimbalLockEnabled = false

    //        pov.constraints = [lookAt]





    //  This seems to produce the same results

    //        let rotationAction = SCNAction.rotateTo(x: destination.eulerAngles.x, y: destination.eulerAngles.y, z: destination.eulerAngles.z,  duration: 1, usesShortestUnitArc: true)

    //        let positionAction = SCNAction.move(to: destination.position, duration: 1)

    //        let group = SCNAction.group([rotationAction, positionAction])

    //        pov.runAction(group)







    // Same weird rotation

    //        SCNTransaction.begin()

    //        pov.pivot = phoneNode.pivot

    //        SCNTransaction.animationDuration = 3

    //        pov.position = destination.position

    //        pov.rotation = destination.rotation

    //        SCNTransaction.commit()





}

}