Value of optional type must be unwrapped to a value of type : <p>I'm trying to have a sceneView load a scene but I get the error <em>Value of optional type 'SCNScene?' must be unwrapped to a value of type 'SCNScene'</em> With options of <em>Coalesce using '??' to provide a default when the optional value contains 'nil'</em> or <em>Force-unwrap using '!' to abort execution if the optional value contains 'nil'</em></p>

<pre class="lang-swift prettyprint-override"><code>override func viewDidLoad() {
        super.viewDidLoad()
        sceneView.scene = SCNScene(named: "Models.scnassets/CDMTEST1");

        VirtualObject.readCoreData()
    }
</code></pre>

<p>Error message : <em>Value of optional type 'SCNScene?' must be unwrapped to a value of type 'SCNScene'</em>
<em>Coalesce using '??' to provide a default when the optional value contains 'nil'</em>
<em>Force-unwrap using '!' to abort execution if the optional value contains 'nil'</em></p>
