I'm trying to add a Viewport2DVisual3D to a Viewport3D in code, but the visual isn't showing up. Any help understanding why not would be appreciated. The following is the code for the main window.

Is it sufficient to just add the Viewport2DVisual3D to the children of the Viewport3D in order for it to be rendered?

public partial class Window1 : System.Windows.Window
{

    public Window1()
    {
        InitializeComponent();

        this.Loaded += new RoutedEventHandler(temp);
    }


    public void temp(object sender, RoutedEventArgs e)
    {
        Viewport2DVisual3D test = new Viewport2DVisual3D();
        MeshGeometry3D testGeometry = new MeshGeometry3D();

        Vector3D CameraLookDirection = Main_Target_CameraOR20.LookDirection;

        // Calculate the Positions based on the Camera 
        Point3DCollection myPoint3DCollection = new Point3DCollection();
        myPoint3DCollection.Add(new Point3D(-1, 1, 0));
        myPoint3DCollection.Add(new Point3D(-1, -1, 0));
        myPoint3DCollection.Add(new Point3D(1, -1, 0));
        myPoint3DCollection.Add(new Point3D(1, 1, 0));
        testGeometry.Positions = myPoint3DCollection;

        PointCollection myPointCollection = new PointCollection();
        myPointCollection.Add(new Point(0, 0));
        myPointCollection.Add(new Point(0, 1));
        myPointCollection.Add(new Point(1, 1));
        myPointCollection.Add(new Point(1, 0));
        testGeometry.TextureCoordinates = myPointCollection;

        Int32Collection triangleIndicesCollection = new Int32Collection();
        triangleIndicesCollection.Add(0);
        triangleIndicesCollection.Add(1);
        triangleIndicesCollection.Add(2);
        triangleIndicesCollection.Add(2);
        triangleIndicesCollection.Add(3);
        triangleIndicesCollection.Add(0);
        testGeometry.TriangleIndices = triangleIndicesCollection;


        DiffuseMaterial myDiffuseMaterial = new DiffuseMaterial(Brushes.White);
        Viewport2DVisual3D.SetIsVisualHostMaterial(myDiffuseMaterial, true);

        Transform3DGroup myTransform3DGroup = new Transform3DGroup();
        ScaleTransform3D myScaleTransform3D = new ScaleTransform3D();
        myScaleTransform3D.ScaleX = 2;
        myScaleTransform3D.ScaleY = 2;
        myScaleTransform3D.ScaleZ = 2;

        TranslateTransform3D myTranslateTransform3D = new TranslateTransform3D();

        myTranslateTransform3D.OffsetX = -27;
        myTranslateTransform3D.OffsetY = 13;
        myTranslateTransform3D.OffsetZ = 6;


        RotateTransform3D rotateTransform = new RotateTransform3D()
        {
            Rotation = new AxisAngleRotation3D
            {
                Angle = -50,
                Axis = new Vector3D(0, 1, 0)
            }
        };

        myTransform3DGroup.Children.Add(myTranslateTransform3D);
        myTransform3DGroup.Children.Add(myScaleTransform3D);
        myTransform3DGroup.Children.Add(rotateTransform);
        test.Transform = myTransform3DGroup;

        Button myButton = new Button();
        myButton.Content = "Test Button";

        test.Material = myDiffuseMaterial;
        test.Geometry = testGeometry;
        test.Visual = myButton;

        ZAM3DViewport3D.Children.Add(test);
    }
}