Lighting problem

namespace game
{
    public class Form1 : Form
    {
        D3D.Device device = null;
        D3D.VertexBuffer vb = null;                
        protected D3D.CustomVertex.PositionNormalColored[] data;
        public Form1()
        {
            InitD3D();
            this.Size = new Size(800, 600);
            this.Text = "GAME";
        }
        public void InitD3D()
        {
            D3D.PresentParameters param = new D3D.PresentParameters();
            param.Windowed = true;            
            param.SwapEffect = D3D.SwapEffect.Discard;
            param.AutoDepthStencilFormat = D3D.DepthFormat.D16;            
            data = new D3D.CustomVertex.PositionNormalColored[3];
            device = new D3D.Device(0, D3D.DeviceType.Hardware, this, D3D.CreateFlags.SoftwareVertexProcessing, param);            
            this.Data();
            //this.SetupMaterials();
            this.Lights();
            this.Camera();
        }
        public void Camera()
        {          
            float angle = Environment.TickCount / 500.0F;
            device.Transform.World = Matrix.RotationY(angle);
            device.Transform.View = Matrix.LookAtLH(new Vector3(0, 0.5F, -3), 
            new Vector3(0, 0.5F, 0), new Vector3(0, 1, 0));
            device.Transform.Projection = Matrix.PerspectiveFovLH((float)Math.PI/4.0F, 1.0F, 1.0F, 3.25F);
        }
        protected void SetupMaterials()
        {
            D3D.Material mat = new D3D.Material();                      
            mat.Diffuse = Color.Blue;            
            mat.Specular = Color.LightGray;
            mat.SpecularSharpness = 15.0F;
            device.Material = mat;            
            device.RenderState.SpecularEnable = true;
        }
        public void Lights()
        {           
                device.Lights[0].Diffuse = Color.White;
                device.Lights[0].Type = D3D.LightType.Directional;
                device.Lights[0].Direction = new Vector3(-1, -1, -3);
                device.Lights[0].Update();
                device.Lights[0].Enabled = true;
                device.RenderState.Ambient = Color.White;                                        
        }       
        public void Data()
        {
            vb = new D3D.VertexBuffer(typeof(D3D.CustomVertex.PositionNormalColored), data.Length, device, D3D.Usage.WriteOnly, D3D.CustomVertex.PositionNormalColored.Format, D3D.Pool.Managed);
            data[0] = new D3D.CustomVertex.PositionNormalColored(0, 1, 0, 0, 0, 1, Color.Purple.ToArgb());
            data[1] = new D3D.CustomVertex.PositionNormalColored(-0.5f, 0, 0, 0, 0, 1, Color.Red.ToArgb());
            data[2] = new D3D.CustomVertex.PositionNormalColored(0.5f, 0, 0, 0, 0, 1, Color.Green.ToArgb());
            vb.SetData(data, 0, D3D.LockFlags.None);
        }                
        public void Render()
        {
            device.VertexFormat = D3D.CustomVertex.PositionNormalColored.Format;
            device.Clear(D3D.ClearFlags.Target, Color.Orange, 1.0f, 0);
            //device.RenderState.Lighting = false;
            device.RenderState.CullMode = D3D.Cull.None;
            device.BeginScene();
            this.Camera();
            device.SetStreamSource(0, vb, 0);
            device.DrawPrimitives(D3D.PrimitiveType.TriangleList, 0, 1);
            device.EndScene();
            device.Present();
        }        
        protected override void OnKeyPress(KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)Keys.Return)
            {
                this.Close();
            }
            if (e.KeyChar == (char)Keys.Escape)
            {
                this.Close();
            }
        }        
        public static void Main()
        {
            Form1 form = new Form1();
            form.Show();
            while (form.Created)
            {
                form.Render();                
                Application.DoEvents();
            }
        }
    }
}