WPF and 3D to create a bowl effect

Ah yes, here you go - you can now drag the red rectangle around the bowl - enjoy!

<Window x:Class="wpfbowl.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="500" Width="500"
    DataContext="{Binding RelativeSource={RelativeSource Self}}" MouseDown="Window_MouseDown" MouseMove="Window_MouseMove" MouseUp="Window_MouseUp" >
<Window.Resources>
    <Transform3DGroup x:Key="WorldTrans">

        <RotateTransform3D>
            <RotateTransform3D.Rotation>
                <AxisAngleRotation3D x:Name="myAngleRotation" Axis="0,0,1" Angle="{Binding RotationLeftRight}" />

            </RotateTransform3D.Rotation>

        </RotateTransform3D>
        <RotateTransform3D>
            <RotateTransform3D.Rotation>
                <AxisAngleRotation3D x:Name="myAngleRotation2" Axis="1,0,0" Angle="{Binding RotationUpDown}" />

            </RotateTransform3D.Rotation>

        </RotateTransform3D>
    </Transform3DGroup>
</Window.Resources>
    <StackPanel>
    <Viewport3D Name="mainViewport" ClipToBounds="True" HorizontalAlignment="Stretch" Margin="0" Height="500" >
        <Viewport3D.Camera>
            <PerspectiveCamera 
          LookDirection="0,5,0"
          UpDirection="0,0,1"
          Position="0,-10,0" 
          />
        </Viewport3D.Camera>

        <ModelVisual3D  >
        <ModelVisual3D>
            <ModelVisual3D.Content>

                <Model3DGroup>

                    <PointLight Position="0,-10,0" Range="150" Color="White" />


                    </Model3DGroup>

            </ModelVisual3D.Content>
        </ModelVisual3D>
    </ModelVisual3D>


    <ModelVisual3D Transform="{StaticResource WorldTrans}">
        <ModelVisual3D Content="{Binding Models}">

        </ModelVisual3D>
    </ModelVisual3D>
        <ModelVisual3D >
            <ModelVisual3D Content="{Binding BowlModel}">

            </ModelVisual3D>
        </ModelVisual3D>

    </Viewport3D>
    </StackPanel>
</Window>

      

        
        
        
      

    

and the code behind ...

using System;
using System.ComponentModel;
using System.Timers;
using System.Windows.Media;
using System.Windows.Media.Media3D;
using System.Windows.Threading;
using System.Windows;
using System.Windows.Input;

namespace wpfbowl
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : INotifyPropertyChanged
{
    public Window1()
    {
        InitModels();
        InitializeComponent();

    }

    private Model3DGroup _cube;
    private bool _cubeSelected;
    private bool _cubeMoving;
    private Point3D _startPoint;
    private Point3D _currentPoint;

    public void InitModels()
    {
        const int bowlQuality = 20;
        Models = new Model3DGroup();
        BowlModel = new Model3DGroup();

        _cube = GetCube(GetSurfaceMaterial(Colors.Red), new Point3D(0, 2.6, 0), new Size3D(1.5, 0.2, 2));
        Models.Children.Add(_cube);

        var bowl = CreateBowl(new Point3D(0, 0, 0), 3, bowlQuality, bowlQuality, GetSurfaceMaterial(Colors.Green));
        BowlModel.Children.Add(bowl);
    }


    private readonly Timer _timer;

    public Model3DGroup Models { get; set; }

    public Model3DGroup BowlModel { get; set; }

    private double _rotationLeftRight;
    public double RotationLeftRight
    {
        get { return _rotationLeftRight; }
        set
        {
            if (_rotationLeftRight == value) return;
            _rotationLeftRight = value;
            OnPropertyChanged("RotationLeftRight");
        }
    }

    private double _rotationUpDown;
    public double RotationUpDown
    {
        get { return _rotationUpDown; }
        set
        {
            if (_rotationUpDown == value) return;
            _rotationUpDown = value;
            OnPropertyChanged("RotationUpDown");
        }
    }


    public static Model3DGroup CreateBowl(Point3D center, double radius, int u, int v, MaterialGroup materialGroup)
    {
        var bowl = new Model3DGroup();
        if (u < 2 || v < 2) return null;
        var pts = new Point3D[u, v];
        for (var i = 0; i < u; i++)
        {
            for (var j = 0; j < v; j++)
            {
                pts[i, j] = GetPosition(radius, i * 180 / (u - 1), j * 360 / (v - 1));
                pts[i, j] += (Vector3D)center;
            }
        }

        var p = new Point3D[4];
        for (var i = 0; i < (u /2) - 1; i++)
        {
            for (var j = 0; j <  v   - 1; j++)
            {
                p[0] = pts[i, j];
                p[1] = pts[i + 1, j];
                p[2] = pts[i + 1, j + 1];
                p[3] = pts[i, j + 1];
                bowl.Children.Add(CreateTriangleModel(materialGroup, p[0], p[1], p[2]));
                bowl.Children.Add(CreateTriangleModel(materialGroup, p[2], p[1], p[0]));
                bowl.Children.Add(CreateTriangleModel(materialGroup, p[2], p[3], p[0]));
                bowl.Children.Add(CreateTriangleModel(materialGroup, p[0], p[3], p[2]));
            }
        }
        return bowl;
    }


    private static Model3DGroup CreateTriangleModel(Material material, Point3D p0, Point3D p1, Point3D p2)
    {
        var mesh = new MeshGeometry3D();
        mesh.Positions.Add(p0);
        mesh.Positions.Add(p1);
        mesh.Positions.Add(p2);
        mesh.TriangleIndices.Add(0);
        mesh.TriangleIndices.Add(1);
        mesh.TriangleIndices.Add(2);
        var normal = CalculateNormal(p0, p1, p2);
        mesh.Normals.Add(normal);
        mesh.Normals.Add(normal);
        mesh.Normals.Add(normal);

        var model = new GeometryModel3D(mesh, material);

        var group = new Model3DGroup();
        group.Children.Add(model);
        return group;
    }

    private static Vector3D CalculateNormal(Point3D p0, Point3D p1, Point3D p2)
    {
        var v0 = new Vector3D(p1.X - p0.X, p1.Y - p0.Y, p1.Z - p0.Z);
        var v1 = new Vector3D(p2.X - p1.X, p2.Y - p1.Y, p2.Z - p1.Z);
        return Vector3D.CrossProduct(v0, v1);
    }

    private static Point3D GetPosition(double radius, double theta, double phi)
    {
        var pt = new Point3D();
        var snt = Math.Sin(theta * Math.PI / 180);
        var cnt = Math.Cos(theta * Math.PI / 180);
        var snp = Math.Sin(phi * Math.PI / 180);
        var cnp = Math.Cos(phi * Math.PI / 180);
        pt.X = radius * snt * cnp;
        pt.Y = radius * cnt;
        pt.Z = -radius * snt * snp;
        return pt;
    }

    public static MaterialGroup GetSurfaceMaterial(Color colour)
    {
        var materialGroup = new MaterialGroup();
        var emmMat = new EmissiveMaterial(new SolidColorBrush(colour));
        materialGroup.Children.Add(emmMat);
        materialGroup.Children.Add(new DiffuseMaterial(new SolidColorBrush(colour)));
        var specMat = new SpecularMaterial(new SolidColorBrush(Colors.White), 30);
        materialGroup.Children.Add(specMat);
        return materialGroup;
    }

    public static Model3DGroup GetCube(MaterialGroup materialGroup, Point3D point, Size3D size)
    {
        var farPoint = new Point3D(point.X - (size.X / 2), point.Y - (size.Y / 2), point.Z - (size.Z / 2));
        var nearPoint = new Point3D(point.X + (size.X / 2), point.Y + (size.Y / 2), point.Z + (size.Z / 2));
        var cube = new Model3DGroup();

        var p0 = new Point3D(farPoint.X, farPoint.Y, farPoint.Z);
        var p1 = new Point3D(nearPoint.X, farPoint.Y, farPoint.Z);
        var p2 = new Point3D(nearPoint.X, farPoint.Y, nearPoint.Z);
        var p3 = new Point3D(farPoint.X, farPoint.Y, nearPoint.Z);
        var p4 = new Point3D(farPoint.X, nearPoint.Y, farPoint.Z);
        var p5 = new Point3D(nearPoint.X, nearPoint.Y, farPoint.Z);
        var p6 = new Point3D(nearPoint.X, nearPoint.Y, nearPoint.Z);
        var p7 = new Point3D(farPoint.X, nearPoint.Y, nearPoint.Z);
        //front side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p3, p2, p6));
        cube.Children.Add(CreateTriangleModel(materialGroup, p3, p6, p7));
        //right side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p2, p1, p5));
        cube.Children.Add(CreateTriangleModel(materialGroup, p2, p5, p6));
        //back side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p1, p0, p4));
        cube.Children.Add(CreateTriangleModel(materialGroup, p1, p4, p5));
        //left side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p0, p3, p7));
        cube.Children.Add(CreateTriangleModel(materialGroup, p0, p7, p4));
        //top side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p7, p6, p5));
        cube.Children.Add(CreateTriangleModel(materialGroup, p7, p5, p4));
        //bottom side triangles
        cube.Children.Add(CreateTriangleModel(materialGroup, p2, p3, p0));
        cube.Children.Add(CreateTriangleModel(materialGroup, p2, p0, p1));
        return cube;
    }


    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string name)
    {
        var handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }

    #endregion

    private void Window_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
    {

            var mousePos = e.GetPosition(mainViewport);
            var hitParams = new PointHitTestParameters(mousePos);
            VisualTreeHelper.HitTest(mainViewport, null, ResultCallback, hitParams);


    }

    public HitTestResultBehavior ResultCallback(HitTestResult result)
    {
        // Did we hit 3D?
        var rayResult = result as RayHitTestResult;
        if (rayResult != null)
        {
            // Did we hit a MeshGeometry3D?
            var rayMeshResult = rayResult as RayMeshGeometry3DHitTestResult;

            if (rayMeshResult != null)
            {
                if (_cubeSelected)
                {
                    _cubeMoving = true;
                    _currentPoint = rayMeshResult.PointHit;
                    RotationLeftRight = (_startPoint.X - _currentPoint.X) * 15;
                    RotationUpDown = (_currentPoint.Z -_startPoint.Z)*15;
                }
                else
                {
                    var model = rayMeshResult.ModelHit;
                    foreach (var c in _cube.Children)
                    {
                        if (c.GetType() != typeof(Model3DGroup)) continue;
                        var model3DGroup = (Model3DGroup)c;
                        foreach (var sc in model3DGroup.Children)
                        {
                            if (model != sc) continue;

                            _cubeSelected = true;
                            _startPoint = rayMeshResult.PointHit;

                        }
                    } 
                }

            }
        }
        return HitTestResultBehavior.Continue;
    }

    private void Window_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
    {
        if (!_cubeSelected) return;
        var mousePos = e.GetPosition(mainViewport);
        var hitParams = new PointHitTestParameters(mousePos);
        VisualTreeHelper.HitTest(mainViewport, null, ResultCallback, hitParams);
    }

    private void Window_MouseUp(object sender, MouseButtonEventArgs e)
    {
        if (!_cubeSelected) return;
        _cubeSelected = false;
        _cubeMoving = false;
    }

}
}