SCNPhysicsVehicle, wheel are rotate 90 deg - scenekit

Question

I'm try to study Scenekit and SCNPhysicsVehicle, I created a simple car as per picture below:
i wrote the following code that should load the physics to the model and place it to the scene.
func setupVeicles(nodePos: SCNVector3){
// load file usdz
let truck = loadAssetWithName(nameFile: "car", nameNode: "car", type: "usdz", scale: SCNVector3(1, 1, 1))
let chassie = truck.childNode(withName: "Chassie", recursively: true)!
// add chassie at position touch
chassie.position = SCNVector3(nodePos.x, nodePos.y+0.1, nodePos.z)
//Set the physic body
let body = SCNPhysicsBody.dynamic()
body.physicsShape = SCNPhysicsShape(node: chassie)
body.categoryBitMask = BodyType.car.rawValue //2 int, assegnato solo a quel oggetto
body.collisionBitMask = BodyType.floor.rawValue //1 con cosa puo collidere
body.contactTestBitMask = BodyType.floor.rawValue //1 attiva il delegato
body.allowsResting = false
body.mass = 5
body.restitution = 0.1
body.friction = 0.5
body.rollingFriction = 0
chassie.physicsBody = body
// Load the wheel
let wheelFL = chassie.childNode(withName: "WheelFL", recursively: true)!
let wheelFR = chassie.childNode(withName: "WheelFR", recursively: true)!
let wheelBL = chassie.childNode(withName: "WheelBL", recursively: true)!
let wheelBR = chassie.childNode(withName: "WheelBR", recursively: true)!
// test rotate , but not work
// wheelFL.eulerAngles = SCNVector3(deg2rad(90), 0, 0)
// wheelPhysic
let phywheelFL = createPhysicsVehicleWheel(wheelNode: wheelFL, position: SCNVector3(-0.212, -0.085, 0.146))
let phywheelFR = createPhysicsVehicleWheel(wheelNode: wheelFR, position: SCNVector3(-0.212, -0.085, -0.15))
let phywheelBL = createPhysicsVehicleWheel(wheelNode: wheelBL, position: SCNVector3(0.182, -0.085, 0.15))
let phywheelBR = createPhysicsVehicleWheel(wheelNode: wheelBR, position: SCNVector3(0.182, -0.085, -0.15))
let physicsVehicle = SCNPhysicsVehicle(chassisBody: chassie.physicsBody!, wheels: [phywheelFL,phywheelFR,phywheelBL,phywheelBR])
self.arView.scene.physicsWorld.addBehavior(physicsVehicle)
self.arView.scene.rootNode.addChildNode(chassie)
}
func createPhysicsVehicleWheel(wheelNode: SCNNode, position: SCNVector3) -> SCNPhysicsVehicleWheel {
let wheel = SCNPhysicsVehicleWheel(node: wheelNode)
wheel.connectionPosition = position
wheel.axle = SCNVector3(x: -1.0, y: 0, z: 0)
wheel.maximumSuspensionTravel = 4.0
wheel.maximumSuspensionForce = 100
wheel.suspensionRestLength = 0.08
wheel.suspensionDamping = 2.0
wheel.suspensionStiffness = 2.0
wheel.suspensionCompression = 4.0
wheel.radius = 0.04
wheel.frictionSlip = 0.9
return wheel
}
Can't understand why my wheel are rotate 90 deg as you cans se on the picture:
Why this wheel are like this? how to rotate them.. I tried to rotate the node but nothing happen..

Answer 1

Download the file rc_car.dae from the Scenekit Demo App that Apple provided in the past.
https://github.com/NXAristotle/appleSample/tree/master/SceneKitVehicleDemo/SceneKitVehicle/resources
You will see, that the geometry is a bit more complex, containing subnodes on the wheels. I ran into a similar issue. Then I used Blender to adapt the geometry the same way as it is in rc_car.dae to my own model. It was quite a bit of work.
Export it to DAE and use it in SceneKit.
If you need code examples, I can provide, but what you made looks quite good to me.