public MainViewModel()
        {
            RenderTechniquesManager = new DefaultRenderTechniquesManager();
            RenderTechnique = RenderTechniquesManager.RenderTechniques[DefaultRenderTechniqueNames.Blinn];
            EffectsManager = new DefaultEffectsManager(RenderTechniquesManager);

            // ----------------------------------------------
            // titles
            this.Title = "Lighting Demo";
            this.SubTitle = "WPF & SharpDX";

            // ----------------------------------------------
            // camera setup
            this.Camera = new PerspectiveCamera { Position = new Point3D(8, 9, 7), LookDirection = new Vector3D(-5, -12, -5), UpDirection = new Vector3D(0, 1, 0) };

            // ----------------------------------------------
            // setup scene
            this.AmbientLightColor = new Color4(0.2f, 0.2f, 0.2f, 1.0f);

            this.RenderLight1 = true;
            this.RenderLight2 = true;
            this.RenderLight3 = true;
            this.RenderLight4 = true;

            this.Light1Color = (Color4)Color.White;
            this.Light2Color = (Color4)Color.Red;
            this.Light3Color = (Color4)Color.LightYellow;
            this.Light4Color = (Color4)Color.LightBlue;

            this.Light2Attenuation = new Vector3(1.0f, 0.5f, 0.10f);
            this.Light3Attenuation = new Vector3(1.0f, 0.1f, 0.05f);
            this.Light4Attenuation = new Vector3(1.0f, 0.2f, 0.0f);

            this.Light1Direction = new Vector3(0, -10, -10);
            this.Light1Transform = new TranslateTransform3D(-Light1Direction.ToVector3D());
            this.Light1DirectionTransform = CreateAnimatedTransform2(-Light1Direction.ToVector3D(), new Vector3D(0, 1, -1), 24);

            this.Light2Transform = CreateAnimatedTransform1(new Vector3D(-4, 0, 0), new Vector3D(0, 0, 1), 3);
            this.Light3Transform = CreateAnimatedTransform1(new Vector3D(0, 0, 4), new Vector3D(0, 1, 0), 5);

            this.Light4Direction = new Vector3(0, -5, 0);
            this.Light4Transform = new TranslateTransform3D(-Light4Direction.ToVector3D());
            this.Light4DirectionTransform = CreateAnimatedTransform2(-Light4Direction.ToVector3D(), new Vector3D(1, 0, 0), 12);

            // ----------------------------------------------
            // light model3d
            var sphere = new MeshBuilder();
            sphere.AddSphere(new Vector3(0, 0, 0), 0.2);
            Sphere = sphere.ToMeshGeometry3D();
            this.LightModelMaterial = new PhongMaterial
            {
                AmbientColor = Color.Gray,
                DiffuseColor = Color.Gray,
                EmissiveColor = Color.Yellow,
                SpecularColor = Color.Black,
            };

            // ----------------------------------------------
            // scene model3d
            var b1 = new MeshBuilder(true, true, true);
            b1.AddSphere(new Vector3(0.25f, 0.25f, 0.25f), 0.75, 64, 64);
            b1.AddBox(-new Vector3(0.25f, 0.25f, 0.25f), 1, 1, 1, BoxFaces.All);
            b1.AddBox(-new Vector3(5.0f, 0.0f, 0.0f), 1, 1, 1, BoxFaces.All);
            b1.AddSphere(new Vector3(5f, 0f, 0f), 0.75, 64, 64);
            b1.AddCylinder(new Vector3(0f, -3f, -5f), new Vector3(0f, 3f, -5f), 1.2, 64);

            this.Model = b1.ToMeshGeometry3D();
            this.ModelTransform = new Media3D.TranslateTransform3D(0, 0, 0);
            this.ModelMaterial = PhongMaterials.Chrome;
            //this.ModelMaterial.TextureMap = new BitmapImage(new System.Uri(@"TextureCheckerboard2.jpg", System.UriKind.RelativeOrAbsolute));
            this.ModelMaterial.NormalMap = new BitmapImage(new System.Uri(@"TextureCheckerboard2_dot3.jpg", System.UriKind.RelativeOrAbsolute));
            //odelMaterial.NormalMap = new BitmapImage(new System.Uri(@"TextureNoise1_dot3.jpg", System.UriKind.RelativeOrAbsolute));

            // ----------------------------------------------
            // floor model3d
            var b2 = new MeshBuilder(true, true, true);
            b2.AddBox(new Vector3(0.0f, -5.0f, 0.0f), 15, 0.1, 15, BoxFaces.All);
            b2.AddSphere(new Vector3(-5.0f, -5.0f, 5.0f), 4, 64, 64);
            b2.AddCone(new Vector3(6f, -9f, -6f), new Vector3(6f, -1f, -6f), 4f, true, 64);
            this.Floor = b2.ToMeshGeometry3D();
            this.FloorTransform = new Media3D.TranslateTransform3D(0, 0, 0);
            this.FloorMaterial = new PhongMaterial
            {
                AmbientColor = Color.Gray,
                DiffuseColor = new Color4(0.75f, 0.75f, 0.75f, 1.0f),
                SpecularColor = Color.White,
                SpecularShininess = 100f,
                DiffuseMap = new BitmapImage(new System.Uri(@"TextureCheckerboard2.jpg", System.UriKind.RelativeOrAbsolute)),
                NormalMap = new BitmapImage(new System.Uri(@"TextureCheckerboard2_dot3.jpg", System.UriKind.RelativeOrAbsolute)),
            };
        }