一个矩形，围绕一条轴转动，这样的动画，能否实现？

轴是垂直方向的。如下图，然后，矩形围绕轴，旋转。

这样的动画，如何实现？

XML code

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C# code

    public partial class MainWindow : Window    {        int i = 0;        MatrixTransform3D mt3d = new MatrixTransform3D();        public MainWindow()        {            InitializeComponent();            Viewport3D viewport = new Viewport3D();            ModelVisual3D modelvisual = new ModelVisual3D();            Model3DGroup modelgroup = new Model3DGroup();            GeometryModel3D geomodel = new GeometryModel3D();            GeometryModel3D geomodel2 = new GeometryModel3D();            MeshGeometry3D mgeo = new MeshGeometry3D();            MeshGeometry3D mgeo2 = new MeshGeometry3D();            viewport.Camera = new PerspectiveCamera(new Point3D(0, 0.5, 8), new Vector3D(0, 0, -1), new Vector3D(0.5, 0, -1), 45);            mgeo.Positions.Add(new Point3D(-0.5, -0.5, -0.5));            mgeo.Positions.Add(new Point3D(0.5, -0.5, 0.5));            mgeo.Positions.Add(new Point3D(0.5, 0.5, 0.5));            mgeo.Positions.Add(new Point3D(0.5, 0.5, 0.5));            mgeo.Positions.Add(new Point3D(-0.5, 0.5, -0.5));            mgeo.Positions.Add(new Point3D(-0.5, -0.5, -0.5));            mgeo2.Positions.Add(new Point3D(-1.5, 1, -1));            mgeo2.Positions.Add(new Point3D(1.5, 1, -1));            mgeo2.Positions.Add(new Point3D(1.5, 1.1, -1));            mgeo2.Positions.Add(new Point3D(1.5, 1.1, -1));            mgeo2.Positions.Add(new Point3D(-1.5, 1.1, -1));            mgeo2.Positions.Add(new Point3D(-1.5, 1, -1));            geomodel.Geometry = mgeo;            geomodel.Material = new DiffuseMaterial(Brushes.Black);            geomodel.Transform = mt3d;            geomodel.BackMaterial = new DiffuseMaterial(Brushes.Black);            geomodel2.Geometry = mgeo2;            geomodel2.Material = new DiffuseMaterial(Brushes.Black);            modelgroup.Children.Add(geomodel);            modelgroup.Children.Add(geomodel2);            modelvisual.Content = modelgroup;            viewport.Children.Add(modelvisual);            grid1.Children.Add(viewport);            CompositionTarget.Rendering += new EventHandler(CompositionTarget_Rendering);        }        void CompositionTarget_Rendering(object sender, EventArgs e)        {            double m11 = Math.Cos(i * 0.01);            double m12 = Math.Sin(i * 0.01);            Matrix3D matrix = new Matrix3D();            matrix.M11 = 0;            matrix.M12 = m11;            matrix.M13 = m12;            matrix.M21 = 1;            matrix.M22 = 0;            matrix.M23 = 0;            matrix.M31 = 0;            matrix.M32 = -m12;            matrix.M33 = m11;            matrix.OffsetY = 0.9 * (1 - m11 + m12);            matrix.OffsetZ = 0.9 * (1 - m12 - m11);            mt3d.Matrix = matrix;            i++;        }    }