ARFace.swift

var originalSource: Any? = nil
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if originalSource == nil {
        originalSource = sceneView.scene.background.contents
        sceneView.scene.background.contents = UIColor.black
    } else {
        sceneView.scene.background.contents = originalSource
        originalSource = nil
    }
}