title: How to find the Joint coordinates(X,Y,Z) ,also how to draw a locus of the tracked joint?
body: <p>I am trying to develop a logic to recognize a circle which is made by users right hand, I got the code to draw the skeleton and track from the sample code, </p>
  
  <pre><code>private void SensorSkeletonFrameReady(object sender, SkeletonFrameReadyEventArgs e)
      {
          Skeleton[] skeletons = new Skeleton[0];
  
          using (SkeletonFrame skeletonFrame = e.OpenSkeletonFrame())
          {
              if (skeletonFrame != null)
              {
                  skeletons = new Skeleton[skeletonFrame.SkeletonArrayLength];
                  skeletonFrame.CopySkeletonDataTo(skeletons);
              }
          }
  
          using (DrawingContext dc = this.drawingGroup.Open())
          {
              // Draw a transparent background to set the render size
              dc.DrawRectangle(Brushes.Black, null, new Rect(0.0, 0.0, RenderWidth, RenderHeight));
  
              if (skeletons.Length != 0)
              {
                  foreach (Skeleton skel in skeletons)
                  {
                      RenderClippedEdges(skel, dc);
  
                      if (skel.TrackingState == SkeletonTrackingState.Tracked)
                      {
                          this.DrawBonesAndJoints(skel, dc);
                      }
                      else if (skel.TrackingState == SkeletonTrackingState.PositionOnly)
                      {
                          dc.DrawEllipse(
                          this.centerPointBrush,
                          null,
                          this.SkeletonPointToScreen(skel.Position),
                          BodyCenterThickness,
                          BodyCenterThickness);
                      }
                  }
              }
  
              // prevent drawing outside of our render area
              this.drawingGroup.ClipGeometry = new RectangleGeometry(new Rect(0.0, 0.0, RenderWidth, RenderHeight));
          }
      }
  </code></pre>
  
  <p>What I want to do now is to track the coordinates of users right hand for gesture recognition,</p>
  
  <p>Here is how I am planning to get the job done:</p>
  
  <ol>
  <li>Start the gesture</li>
  <li>Draw the circled gesture, Make sure to store the coordinates for start and then keep noting the coordinates for every 45 degree shift of the Joint from the start, for 8 octants we will get 8 samples.</li>
  <li>For making a decision that a circle was drawn we can just check the relation ship between the eight samples.</li>
  </ol>
  
  <p>Also, in the depthimage I want to show the locus of the drawn gesture, so as the handpoint moves it leaves a trace behind so at the end we will get a figure which was drawn by an user. I have no idea how to achieve this.</p>