Geek asks and answers

Display a 3d model as a 3D mesh object using wpf 3D graphics

I am working on a platform C# .Netwith 3D graphics Wpf. Below is the code stream:

1) I take the depth data from the kinect and pass it to a single function that calculates three points.

private void display3DView ()

{ 
   while(loop_run)
    {
       using ( DepthImageFrame depthFrame = sensor.DepthStream.OpenNextFrame(1000))
      {
             if (depthFrame  == null)  continue;

            Point3DCollection PointCloud ;

            depthFrame.CopyDepthImagePixelDataTo(this.depthImagePixels);

            float[,] ImageArray = new float[320, 240];

            short [ ,] depth = new short[240,320]; 

            for (int i = 0; i < 240; i++)
            {
              for (int j = 0; j <320; j++)
              {
                depth[i,j]= depthImagePixels[j+i *320].Depth;

                 ImageArray[i,j] =(float)depth[i,j]/(float)1000;
             }
           }
          PointCloud =Calculate_PointCloud(ImageArray); 

          viewModel(PointCloud);   
        }
      }
     }</i>

2) I calculated 3D points with camera parameters and Kinect camera depth data

private Point3DCollection Calculate_PointCloud (float [,] ImageArray) {

   Point3DCollection PointCloud = new Point3DCollection();

    float x_coodinate;``
    float y_coordinate;
    float z_coordinate;
    float thresholdvalue = 2.0f;

    for (int i = 0; i < 239; ++i)
    {
        for (int j = 0; j < 319; ++j)
        {
            if (Math.Abs(ImageArray[i, j] - ImageArray[i, j + 1]) < thresholdvalue && Math.Abs(ImageArray[i, j] - ImageArray[i + 1, j]) < thresholdvalue && Math.Abs(ImageArray[i, j + 1] - ImageArray[i + 1, j]) < thresholdvalue)
            {

                z_coordinate = ImageArray[i, j];
                x_coodinate = ((j - this.PrincipalPointX) * z_coordinate) / FocalLengthX;
                y_coordinate = ((i - this.PrincipalPointY) * z_coordinate) / FocalLengthY;
                Point3D point1 = new Point3D(x_coodinate, y_coordinate, z_coordinate);
                PointCloud.Add(point1);

                z_coordinate = ImageArray[i, j + 1];
                x_coodinate = (((j + 1) - this.PrincipalPointX) * z_coordinate) / FocalLengthX;
                y_coordinate = ((i - this.PrincipalPointY) * z_coordinate) / FocalLengthY;
                Point3D point2 = new Point3D(x_coodinate, y_coordinate, z_coordinate);
                PointCloud.Add(point2);

                z_coordinate = ImageArray[i + 1, j];
                x_coodinate = ((j - this.PrincipalPointX) * z_coordinate) / FocalLengthX;
                y_coordinate = (((i + 1) - this.PrincipalPointY) * z_coordinate) / FocalLengthY;
                Point3D point3 = new Point3D(x_coodinate, y_coordinate, z_coordinate);
                PointCloud.Add(point3);

              }
            }
        }
    return PointCloud;
}</i>

3) Here I am transformed into a set of triangles with normal information of each three-dimensional point and pass these triangles to the 3D mesh object and render the 3d mesh object using the viewport3D control

       private void viewModel (Point3DCollection points)

       {    
           DirectionalLight DirLight1 = new DirectionalLight();
            DirLight1.Color = Colors.White;
            DirLight1.Direction = new Vector3D(1, 1, 1);
           PerspectiveCamera Camera1 = new PerspectiveCamera();
           Camera1.FarPlaneDistance = 8000;
          Camera1.NearPlaneDistance = 100;
          Camera1.FieldOfView = 10;
          Camera1.Position = new Point3D(0, 0, 1);
          Camera1.LookDirection = new Vector3D(-1, -1, -1);
          Camera1.UpDirection = new Vector3D(0, 1, 0);
           bool combinedvertices = true;
          TriangleModel Triatomesh = new TriangleModel();
          MeshGeometry3D tmesh = new MeshGeometry3D();
          GeometryModel3D msheet = new GeometryModel3D();
          Model3DGroup modelGroup = new Model3DGroup();
          ModelVisual3D modelsVisual = new ModelVisual3D();
          Viewport3D myViewport = new Viewport3D();

         for(int i =0; i<points.Count; i+=3)
        {
            Triatomesh.addTriangleToMesh(points[i],points[i + 1], points[i + 2], tmesh, combinedvertices); 
        }
        msheet.Geometry = tmesh;
       msheet.Material = new DiffuseMaterial(new SolidColorBrush(Colors.White));
       modelGroup.Children.Add(msheet);
       modelGroup.Children.Add(DirLight1);
       modelsVisual.Content = modelGroup;
       myViewport.IsHitTestVisible = false;
      myViewport.Camera = Camera1;
       myViewport.Children.Add(modelsVisual);
       canvas1.Children.Add(myViewport);
       myViewport.Height = canvas1.Height;
       myViewport.Width = canvas1.Width;
       Canvas.SetTop(myViewport, 0);
       Canvas.SetLeft(myViewport, 0);
 } </i>

4) , 3d- ,

 public  void addTriangleToMesh(Point3D p0, Point3D p1, Point3D p2,

        MeshGeometry3D mesh, bool combine_vertices)  

    {
        Vector3D normal = CalculateNormal(p0, p1, p2);

        if (combine_vertices)
        {
            addPointCombined(p0, mesh, normal);
            addPointCombined(p1, mesh, normal);
            addPointCombined(p2, mesh, normal);
        }
        else
        {
            mesh.Positions.Add(p0);
            mesh.Positions.Add(p1);
            mesh.Positions.Add(p2);
              //mesh.TriangleIndices.Add(mesh.TriangleIndices.Count);
           // mesh.TriangleIndices.Add(mesh.TriangleIndices.Count);
           // mesh.TriangleIndices.Add(mesh.TriangleIndices.Count);
            mesh.Normals.Add(normal);
            mesh.Normals.Add(normal);
            mesh.Normals.Add(normal);
        }
    }

public  Vector3D CalculateNormal(Point3D P0, Point3D P1, Point3D P2)   //static
    {
        Vector3D v0 = new Vector3D(P1.X - P0.X, P1.Y - P0.Y, P1.Z - P0.Z);

        Vector3D v1 = new Vector3D(P2.X - P1.X, P2.Y - P1.Y, P2.Z - P1.Z);

        return Vector3D.CrossProduct(v0, v1);
    }

 public  void addPointCombined(Point3D point, MeshGeometry3D mesh, Vector3D normal)  

    {
        bool found = false;
        int i = 0;
        foreach (Point3D p in mesh.Positions)

        {
            if (p.Equals(point))
            {
                found = true;
                mesh.TriangleIndices.Add(i);
                mesh.Positions.Add(point);
                mesh.Normals.Add(normal);
                break;
            }

            i++;
        }

        if (!found)
        {
            mesh.Positions.Add(point);
            mesh.TriangleIndices.Add(mesh.TriangleIndices.Count);
            mesh.Normals.Add(normal);
        }
}

5) XAML

 <Window x:Class="PointCloud3DView.MainWindow"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    Title="PointCloud" Height="653" Width="993" Background="Black" Loaded="Window_Loaded">

<Grid Height="1130" Width="1626">

    <Canvas Height="611" HorizontalAlignment="Left" Name="canvas1" VerticalAlignment="Top"

= "967" = "" /" >

</Grid>

, 3D- Wpf Screen.Please, - ? , ? .

+3
1

WPF 3D :) , , . :

  • . (0,1,0), (-1, -1, -1), , (-1,0, -1). ... ( ), (0,10,0) (0,0,0) :

    Camera1.Position = new Point3D (0, 10, 0);
    Camera1.LookDirection = new Point3D (0,0,0) - Camera1.Position;

  • ( , , ) .      (-1, -1, -1) (1,1,1).

  • trinagle (WPF , , /) -   isntead 0,1,2 try 0,2,1;

nohting , , .

/ / , . , :)

    private void viewModel(Point3DCollection points)
    {
        DirectionalLight DirLight1 = new DirectionalLight();
        DirLight1.Color = Colors.White;
        DirLight1.Direction = new Vector3D(1, 1, 1);

        PerspectiveCamera Camera1 = new PerspectiveCamera();
        Camera1.FarPlaneDistance = 8000;
        //Camera1.NearPlaneDistance = 100; //close object will not be displayed with this option
        Camera1.FieldOfView = 10;   
        //Camera1.Position = new Point3D(0, 0, 1);
        //Camera1.LookDirection = new Vector3D(-1, -1, -1);
        Camera1.Position = new Point3D(0, 0, 10);
        Camera1.LookDirection = new Point3D(0, 0, 0) - Camera1.Position; //focus camera on real center of your model (0,0,0) in this case
        Camera1.UpDirection = new Vector3D(0, 1, 0);
        //you can use constructor to create Camera instead of assigning its properties like:
        //PerspectiveCamera Camera1 = new PerspectiveCamera(new Point3D(0,0,10), new Vector3D(0,0,-1), new Vector3D(0,1,0), 10);


        bool combinedvertices = true;
        TriangleModel Triatomesh = new TriangleModel();
        MeshGeometry3D tmesh = new MeshGeometry3D();
        GeometryModel3D msheet = new GeometryModel3D();
        Model3DGroup modelGroup = new Model3DGroup();
        ModelVisual3D modelsVisual = new ModelVisual3D();
        Viewport3D myViewport = new Viewport3D();

        for (int i = 0; i < points.Count; i += 3)
        {
            Triatomesh.addTriangleToMesh(points[i + 2], points[i + 1], points[i], tmesh, combinedvertices);                
            //I did swap order of vertexes you may try both options with your model               
        }

        msheet.Geometry = tmesh;
        msheet.Material = new DiffuseMaterial(new SolidColorBrush(Colors.White));
        //you can use constructor to create GeometryModel3D instead of assigning its properties like:
        //msheet = new GeometryModel3D(tmesh, new DiffuseMaterial(new SolidColorBrush(Colors.White)));             

        modelGroup.Children.Add(msheet);
        //use AMbientLIght instead of directional
        modelGroup.Children.Add(new AmbientLight(Colors.White));

        modelsVisual.Content =  modelGroup;
        myViewport.IsHitTestVisible = false;

        myViewport.Camera = Camera1;

        myViewport.Children.Add(modelsVisual);

        canvas1.Children.Add(myViewport);
        myViewport.Height = canvas1.Height;
        myViewport.Width = canvas1.Width;
        Canvas.SetTop(myViewport, 0);
        Canvas.SetLeft(myViewport, 0);
    }

Points3DCollection, ( Kinect):

    Point3DCollection points = new Point3DCollection();
    points.Add(new Point3D(0.5, 0, 0.5));
    points.Add(new Point3D(0.5, -0.5, -0.5));
    points.Add(new Point3D(-0.5, -0.1, -0.5));
    viewModel(points);
+1

More articles:


All Articles