So, let's say you want to swap between cameras, provided you have more than one, in a scene. I banged my head on this for a bit of time, primarily because I'm either dim-witted (a real strong possibility) or just too set in my 57-year old ways, trying to change the pointOfView property in SceneView. Eventually, it hit me that all I'm trying to do is change the "withName" String in .childNode(withName: String, recursively: Bool). And boy!, that's easy.
The above code I posted is junk and, frankly, embarrassing. Here's the better code. I hope it helps.
import SwiftUI
import SceneKit
extension SCNScene: ObservableObject {
}
struct SwiftUISceneKitUsingStateObjectVarsContentView: View {
		@State private var povSwitch				= true
	@State private var pointOfView			= "distantCamera"
		@StateObject var aircraftScene			= SCNScene(named: "art.scnassets/ship.scn")!
		var body: some View {
				ZStack {
						Color.black.edgesIgnoringSafeArea(.all)
						SceneView (
								scene: aircraftScene,
								pointOfView: aircraftScene.rootNode.childNode(withName: pointOfView, recursively: true)
						)
						.background(Color.black)
						VStack() {
								Text("Hello, SceneKit!").multilineTextAlignment(.leading).padding()
										.foregroundColor(Color.gray)
										.font(.largeTitle)
								Text("Change the camera.")
										.foregroundColor(Color.gray)
										.font(.title)
								Spacer(minLength: 300)
								Button( action: {
										withAnimation{
												self.povSwitch.toggle()
										}
										 if self.povSwitch == true {
												self.pointOfView = "distantCamera"
										} else {
												self.pointOfView = "aircraftCamera"
										}
								}) {
										Image(systemName: sunlightSwitch ? "video.fill" : "video")
												.imageScale(.large)
												.accessibility(label: Text("Camera Switch"))
												.padding()
								}
						}
				}
				.statusBar(hidden: true)
		}
}
