let cameraNode001 = SCNNode()
cameraNode001.camera = SCNCamera()
scene.rootNode.addChildNode(cameraNode001)
cameraNode001.position = SCNVector3(x: 0, y: 0, z: 15)

let cameraNode002 = SCNNode()
cameraNode002.camera = SCNCamera()
scene.rootNode.addChildNode(cameraNode002)
cameraNode002.position = SCNVector3(x: 10, y: 10, z: 30)

let sceneView = self.view as! SCNView
sceneView.scene = scene


sceneView.pointOfView = cameraNode001

sceneView.pointOfView = cameraNode002