From 29dde32240443a8437592b568d70155a740059d6 Mon Sep 17 00:00:00 2001
From: Andrew B <bibigone@gmail.com>
Date: Wed, 16 Oct 2019 17:27:20 +0300
Subject: [PATCH] Switching to version 0.9.4 of Body Tracking SDK. New joints
 for hands, confidence level for joints, CPU only mode (very slow!)

---
 .../ProcessingParameters.cs                   | 28 ++++++++++++++++
 .../Processor.cs                              |  4 ++-
 .../Program.cs                                |  8 +++++
 .../BackgroundTrackingLoop.cs                 |  4 +--
 .../MainModel.cs                              | 11 +++++--
 .../MainWindow.xaml                           | 16 ++++++----
 .../SkeletonVisualizer.cs                     | 26 +++++++++++++--
 .../TrackerModel.cs                           |  4 +--
 K4AdotNet/BodyTracking/Joint.cs               |  8 +++--
 .../BodyTracking/JointConfidenceLevel.cs      | 28 ++++++++++++++++
 K4AdotNet/BodyTracking/JointType.cs           | 24 ++++++++++++++
 K4AdotNet/BodyTracking/JointTypes.cs          | 30 +++++++++++++++++
 K4AdotNet/BodyTracking/Skeleton.cs            | 30 +++++++++++++++++
 .../BodyTracking/TrackerConfiguration.cs      | 16 ++++++++--
 K4AdotNet/K4AdotNet.xml                       | 25 +++++++++++++++
 K4AdotNet/Sdk.cs                              |  8 ++---
 README.md                                     |  6 ++--
 externals/k4abt/include/k4abttypes.h          | 32 ++++++++++++++++++-
 externals/k4abt/include/k4abtversion.h        |  4 +--
 19 files changed, 281 insertions(+), 31 deletions(-)
 create mode 100644 K4AdotNet/BodyTracking/JointConfidenceLevel.cs

diff --git a/K4AdotNet.Samples.Core.BodyTrackingSpeed/ProcessingParameters.cs b/K4AdotNet.Samples.Core.BodyTrackingSpeed/ProcessingParameters.cs
index 39cb061..15a34aa 100644
--- a/K4AdotNet.Samples.Core.BodyTrackingSpeed/ProcessingParameters.cs
+++ b/K4AdotNet.Samples.Core.BodyTrackingSpeed/ProcessingParameters.cs
@@ -8,6 +8,7 @@ internal sealed class ProcessingParameters
         public const string MKV_FILE_EXTENSION = ".mkv";
 
         public static readonly string MkvPathDescription = "Path to MKV file";
+        public static readonly string CpuOnlyModeDescription = "CPU/GPU mode (C - use only CPU, G - use GPU, default - G)";
         public static readonly string ImplementationDescription = "Optional implementation type (S - single thread, P - pop in background, E - enqueue in background, default - S)";
         public static readonly string StartTimeDescription = "Optional start time of video interval in seconds (default - beginning of recording)";
         public static readonly string EndTimeDescription = "Optional end time of video interval in seconds (default - end of recording)";
@@ -26,6 +27,7 @@ public static bool IsValueLikeToMkvFilePath(string value)
         }
 
         public string MkvPath { get; private set; }
+        public bool CpuOnlyMode { get; private set; }
         public ProcessingImplementation Implementation { get; private set; }
         public TimeSpan? StartTime { get; private set; }
         public TimeSpan? EndTime { get; private set; }
@@ -68,6 +70,32 @@ public bool TrySetMkvPath(string value, out string message)
             return true;
         }
 
+        public bool TrySetCpuOnlyMode(string value, out string message)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                CpuOnlyMode = false;
+                message = null;
+                return true;
+            }
+
+            value = value.Trim().ToLowerInvariant();
+            switch (value)
+            {
+                case "c":
+                    CpuOnlyMode = true;
+                    message = null;
+                    return true;
+                case "g":
+                    CpuOnlyMode = false;
+                    message = null;
+                    return true;
+            }
+
+            message = $"Invalid value. Expected 'C' or 'G'.";
+            return false;
+        }
+
         public bool TrySetImplementation(string value, out string message)
         {
             if (string.IsNullOrWhiteSpace(value))
diff --git a/K4AdotNet.Samples.Core.BodyTrackingSpeed/Processor.cs b/K4AdotNet.Samples.Core.BodyTrackingSpeed/Processor.cs
index ac941a4..052a19b 100644
--- a/K4AdotNet.Samples.Core.BodyTrackingSpeed/Processor.cs
+++ b/K4AdotNet.Samples.Core.BodyTrackingSpeed/Processor.cs
@@ -30,7 +30,9 @@ protected Processor(ProcessingParameters processingParameters)
             playback.GetCalibration(out calibration);
             if (processingParameters.StartTime.HasValue)
                 Seek(processingParameters.StartTime.Value);
-            tracker = new BodyTracking.Tracker(ref calibration);
+            var config = BodyTracking.TrackerConfiguration.Default;
+            config.CpuOnlyMode = processingParameters.CpuOnlyMode;
+            tracker = new BodyTracking.Tracker(ref calibration, config);
         }
 
         public virtual void Dispose()
diff --git a/K4AdotNet.Samples.Core.BodyTrackingSpeed/Program.cs b/K4AdotNet.Samples.Core.BodyTrackingSpeed/Program.cs
index 385f625..3c9bbd8 100644
--- a/K4AdotNet.Samples.Core.BodyTrackingSpeed/Program.cs
+++ b/K4AdotNet.Samples.Core.BodyTrackingSpeed/Program.cs
@@ -62,6 +62,8 @@ private static ProcessingParameters AskProcessingParameters()
             var parameters = new ProcessingParameters();
             if (!AskParameter(ProcessingParameters.MkvPathDescription, parameters.TrySetMkvPath))
                 return null;
+            if (!AskParameter(ProcessingParameters.CpuOnlyModeDescription, parameters.TrySetCpuOnlyMode))
+                return null;
             if (!AskParameter(ProcessingParameters.ImplementationDescription, parameters.TrySetImplementation))
                 return null;
             if (!AskParameter(ProcessingParameters.StartTimeDescription, parameters.TrySetStartTime))
@@ -100,6 +102,11 @@ private static ProcessingParameters ParseCommandLineArguments(string[] args)
                 var arg = args[i].Trim();
                 switch (arg.ToLowerInvariant())
                 {
+                    case "-m":
+                    case "--mode":
+                        if (!ParseArgument(args, ref i, parameters.TrySetCpuOnlyMode))
+                            return null;
+                        break;
                     case "-i":
                     case "--implementation":
                         if (!ParseArgument(args, ref i, parameters.TrySetImplementation))
@@ -168,6 +175,7 @@ private static void PrintHowToUse()
             Console.WriteLine("where: ");
             Console.WriteLine("  <mkvFile> - " + ProcessingParameters.MkvPathDescription);
             Console.WriteLine("  options:");
+            Console.WriteLine("    -m, --mode c|g\t\t" + ProcessingParameters.StartTimeDescription);
             Console.WriteLine("    -i, --implementation s|p|e\t\t" + ProcessingParameters.StartTimeDescription);
             Console.WriteLine("    -s, --startTime <time>\t\t" + ProcessingParameters.StartTimeDescription);
             Console.WriteLine("    -e, --endTime <time>\t\t" + ProcessingParameters.EndTimeDescription);
diff --git a/K4AdotNet.Samples.Wpf.BodyTracker/BackgroundTrackingLoop.cs b/K4AdotNet.Samples.Wpf.BodyTracker/BackgroundTrackingLoop.cs
index d933ab4..2ff1da8 100644
--- a/K4AdotNet.Samples.Wpf.BodyTracker/BackgroundTrackingLoop.cs
+++ b/K4AdotNet.Samples.Wpf.BodyTracker/BackgroundTrackingLoop.cs
@@ -11,9 +11,9 @@ internal sealed class BackgroundTrackingLoop : IDisposable
         private readonly Thread backgroundThread;
         private volatile bool isRunning;
 
-        public BackgroundTrackingLoop(ref Calibration calibration, SensorOrientation sensorOrientation, float smoothingFactor)
+        public BackgroundTrackingLoop(ref Calibration calibration, bool cpuOnlyMode, SensorOrientation sensorOrientation, float smoothingFactor)
         {
-            var config = new TrackerConfiguration { SensorOrientation = sensorOrientation };
+            var config = new TrackerConfiguration { SensorOrientation = sensorOrientation, CpuOnlyMode = cpuOnlyMode };
             tracker = new Tracker(ref calibration, config) { TemporalSmoothingFactor = smoothingFactor };
             isRunning = true;
             backgroundThread = new Thread(BackgroundLoop) { IsBackground = true };
diff --git a/K4AdotNet.Samples.Wpf.BodyTracker/MainModel.cs b/K4AdotNet.Samples.Wpf.BodyTracker/MainModel.cs
index c7283f1..b5c0507 100644
--- a/K4AdotNet.Samples.Wpf.BodyTracker/MainModel.cs
+++ b/K4AdotNet.Samples.Wpf.BodyTracker/MainModel.cs
@@ -44,7 +44,7 @@ public void Playback()
                             disableColor: DisableColor,
                             disableDepth: false,
                             doNotPlayFasterThanOriginalFps: DoNotPlayFasterThanOriginalFps);
-                        var viewModel = new TrackerModel(app, readingLoop, SensorOrientation, SmoothingFactor);
+                        var viewModel = new TrackerModel(app, readingLoop, CpuOnlyMode, SensorOrientation, SmoothingFactor);
                         app.ShowWindowForModel(viewModel);
                     }
                 }
@@ -102,7 +102,7 @@ public void OpenDevice()
                 using (app.IndicateWaiting())
                 {
                     var readingLoop = BackgroundReadingLoop.CreateForDevice(device, DepthMode, ColorResolution, FrameRate);
-                    var viewModel = new TrackerModel(app, readingLoop, SensorOrientation, SmoothingFactor);
+                    var viewModel = new TrackerModel(app, readingLoop, CpuOnlyMode, SensorOrientation, SmoothingFactor);
                     app.ShowWindowForModel(viewModel);
                 }
             }
@@ -117,6 +117,13 @@ public void OpenDevice()
 
         #region Settings
 
+        public bool CpuOnlyMode
+        {
+            get => cpuOnlyMode;
+            set => SetPropertyValue(ref cpuOnlyMode, value, nameof(CpuOnlyMode));
+        }
+        private bool cpuOnlyMode;
+
         public float SmoothingFactor
         {
             get => smoothingFactor;
diff --git a/K4AdotNet.Samples.Wpf.BodyTracker/MainWindow.xaml b/K4AdotNet.Samples.Wpf.BodyTracker/MainWindow.xaml
index 3ddb70c..9d8ab7e 100644
--- a/K4AdotNet.Samples.Wpf.BodyTracker/MainWindow.xaml
+++ b/K4AdotNet.Samples.Wpf.BodyTracker/MainWindow.xaml
@@ -80,21 +80,23 @@
                         <RowDefinition/>
                         <RowDefinition/>
                         <RowDefinition/>
+                        <RowDefinition/>
                     </Grid.RowDefinitions>
-                    <Label Grid.Row="0" Grid.Column="0" Margin="3">Orientation:</Label>
-                    <ComboBox Grid.Row="0" Grid.Column="1" Margin="3"
+                    <CheckBox Grid.Row="0" Grid.Column="1" Margin="3" IsChecked="{Binding CpuOnlyMode}">CPU only mode</CheckBox>
+                    <Label Grid.Row="1" Grid.Column="0" Margin="3">Orientation:</Label>
+                    <ComboBox Grid.Row="1" Grid.Column="1" Margin="3"
                             ItemsSource="{Binding SensorOrientations}"
                             DisplayMemberPath="Value"
                             SelectedValuePath="Key"
                             SelectedValue="{Binding SensorOrientation}"/>
-                    <Label Grid.Row="1" Grid.Column="0" Margin="3,0">Smoothing:</Label>
-                    <Slider Grid.Row="1" Grid.Column="1" Margin="3,0" VerticalAlignment="Bottom"
+                    <Label Grid.Row="2" Grid.Column="0" Margin="3,0">Smoothing:</Label>
+                    <Slider Grid.Row="2" Grid.Column="1" Margin="3,0" VerticalAlignment="Bottom"
                             Minimum="0" Maximum="1" SmallChange="0.05" LargeChange="0.25"
                             TickPlacement="BottomRight"
                             Value="{Binding SmoothingFactor}"/>
-                    <TextBlock Grid.Row="2" Grid.Column="1" FontSize="14" FontWeight="Light" TextAlignment="Left" VerticalAlignment="Top">&lt; low</TextBlock>
-                    <TextBlock Grid.Row="2" Grid.Column="1" FontSize="14" FontWeight="Light" TextAlignment="Right" VerticalAlignment="Top">high &gt;</TextBlock>
-                    <TextBlock Grid.Row="2" Grid.Column="1" FontSize="14" TextAlignment="Center" VerticalAlignment="Top"><Run Text="{Binding SmoothingFactor, Mode=OneWay, StringFormat=0.00}"/></TextBlock>
+                    <TextBlock Grid.Row="3" Grid.Column="1" FontSize="14" FontWeight="Light" TextAlignment="Left" VerticalAlignment="Top">&lt; low</TextBlock>
+                    <TextBlock Grid.Row="3" Grid.Column="1" FontSize="14" FontWeight="Light" TextAlignment="Right" VerticalAlignment="Top">high &gt;</TextBlock>
+                    <TextBlock Grid.Row="3" Grid.Column="1" FontSize="14" TextAlignment="Center" VerticalAlignment="Top"><Run Text="{Binding SmoothingFactor, Mode=OneWay, StringFormat=0.00}"/></TextBlock>
                 </Grid>
             </StackPanel>
         </GroupBox>
diff --git a/K4AdotNet.Samples.Wpf.BodyTracker/SkeletonVisualizer.cs b/K4AdotNet.Samples.Wpf.BodyTracker/SkeletonVisualizer.cs
index efe1c25..f37cb80 100644
--- a/K4AdotNet.Samples.Wpf.BodyTracker/SkeletonVisualizer.cs
+++ b/K4AdotNet.Samples.Wpf.BodyTracker/SkeletonVisualizer.cs
@@ -33,7 +33,9 @@ public SkeletonVisualizer(Dispatcher dispatcher, int widthPixels, int heightPixe
             JointCircleRadius = heightPixels / 70;
             JointBorder = new Pen(Brushes.Black, JointCircleRadius / 4);
             BonePen = new Pen(Brushes.White, JointCircleRadius * 2 / 3);
-            JointFill = Brushes.LightGray;
+            JointFill = Brushes.LightGreen;
+            JointFillLow = Brushes.Yellow;
+            JointFillNone = Brushes.OrangeRed;
         }
 
         /// <summary>
@@ -49,6 +51,12 @@ public SkeletonVisualizer(Dispatcher dispatcher, int widthPixels, int heightPixe
         /// <summary>Visualization setting: brush to fill joint circle.</summary>
         public Brush JointFill { get; set; }
 
+        /// <summary>Visualization setting: brush to fill joint circle for Low confidence.</summary>
+        public Brush JointFillLow { get; set; }
+
+        /// <summary>Visualization setting: brush to fill joint circle for None confidence.</summary>
+        public Brush JointFillNone { get; set; }
+
         /// <summary>Visualization setting: radius of joint circle.</summary>
         public double JointCircleRadius { get; set; }
 
@@ -127,18 +135,30 @@ private void DrawJoints(DrawingContext dc, Skeleton skeleton)
         {
             foreach (var jointType in JointTypes.All)
             {
-                var point2D = ProjectJointToImage(skeleton[jointType]);
+                var joint = skeleton[jointType];
+                var point2D = ProjectJointToImage(joint);
                 if (point2D.HasValue)
                 {
                     var radius = JointCircleRadius;
                     // smaller radius for face features (eyes, ears, nose)
                     if (jointType.IsFaceFeature())
                         radius /= 2;
-                    dc.DrawEllipse(JointFill, JointBorder, point2D.Value, radius, radius);
+                    var fillBrush = JointConfidenceLevelToToBrush(joint.ConfidenceLevel);
+                    dc.DrawEllipse(fillBrush, JointBorder, point2D.Value, radius, radius);
                 }
             }
         }
 
+        private Brush JointConfidenceLevelToToBrush(JointConfidenceLevel confidenceLevel)
+        {
+            switch (confidenceLevel)
+            {
+                case JointConfidenceLevel.None: return JointFillNone;
+                case JointConfidenceLevel.Low: return JointFillLow;
+                default: return JointFill;
+            }
+        }
+
         private readonly Dispatcher dispatcher;
         private readonly int widthPixels;
         private readonly int heightPixels;
diff --git a/K4AdotNet.Samples.Wpf.BodyTracker/TrackerModel.cs b/K4AdotNet.Samples.Wpf.BodyTracker/TrackerModel.cs
index 671ad75..37f9d4f 100644
--- a/K4AdotNet.Samples.Wpf.BodyTracker/TrackerModel.cs
+++ b/K4AdotNet.Samples.Wpf.BodyTracker/TrackerModel.cs
@@ -32,12 +32,12 @@ public TrackerModel()
             DepthColumnWidth = ColorColumnWidth = new GridLength(1, GridUnitType.Star);
         }
 
-        public TrackerModel(IApp app, BackgroundReadingLoop readingLoop, SensorOrientation sensorOrientation, float smoothingFactor)
+        public TrackerModel(IApp app, BackgroundReadingLoop readingLoop, bool cpuOnlyMode, SensorOrientation sensorOrientation, float smoothingFactor)
             : base(app)
         {
             // try to create tracking loop first
             readingLoop.GetCalibration(out calibration);
-            trackingLoop = new BackgroundTrackingLoop(ref calibration, sensorOrientation, smoothingFactor);
+            trackingLoop = new BackgroundTrackingLoop(ref calibration, cpuOnlyMode, sensorOrientation, smoothingFactor);
             trackingLoop.BodyFrameReady += TrackingLoop_BodyFrameReady;
             trackingLoop.Failed += BackgroundLoop_Failed;
 
diff --git a/K4AdotNet/BodyTracking/Joint.cs b/K4AdotNet/BodyTracking/Joint.cs
index 7b957ba..1920cd7 100644
--- a/K4AdotNet/BodyTracking/Joint.cs
+++ b/K4AdotNet/BodyTracking/Joint.cs
@@ -5,8 +5,9 @@ namespace K4AdotNet.BodyTracking
     // Defined in k4abttypes.h:
     // typedef struct _k4abt_joint_t
     // {
-    //     k4a_float3_t position;    /**< The position of the joint specified in millimeters*/
-    //     k4a_quaternion_t orientation; /**< The orientation of the joint specified in normalized quaternion*/
+    //     k4a_float3_t position;
+    //     k4a_quaternion_t orientation;
+    //     k4abt_joint_confidence_level_t confidence_level;
     // } k4abt_joint_t;
     //
     /// <summary>Structure to define a single joint.</summary>
@@ -22,5 +23,8 @@ public struct Joint
 
         /// <summary>The orientation of the joint specified in normalized quaternion.</summary>
         public Quaternion Orientation;
+
+        /// <summary>The confidence level of the joint.</summary>
+        public JointConfidenceLevel ConfidenceLevel;
     }
 }
diff --git a/K4AdotNet/BodyTracking/JointConfidenceLevel.cs b/K4AdotNet/BodyTracking/JointConfidenceLevel.cs
new file mode 100644
index 0000000..e5a49f1
--- /dev/null
+++ b/K4AdotNet/BodyTracking/JointConfidenceLevel.cs
@@ -0,0 +1,28 @@
+namespace K4AdotNet.BodyTracking
+{
+    // Defined in k4abttypes.h:
+    // typedef enum
+    // {
+    //     K4ABT_JOINT_CONFIDENCE_NONE = 0,
+    //     K4ABT_JOINT_CONFIDENCE_LOW = 1,
+    //     K4ABT_JOINT_CONFIDENCE_MEDIUM = 2,
+    //     K4ABT_JOINT_CONFIDENCE_HIGH = 3,
+    //     K4ABT_JOINT_CONFIDENCE_LEVELS_COUNT = 4,
+    // } k4abt_joint_confidence_level_t;
+    //
+    /// <summary>This enumeration specifies the joint confidence level.</summary>
+    public enum JointConfidenceLevel
+    {
+        /// <summary>The joint is out of range (too far from depth camera).</summary>
+        None = 0,
+
+        /// <summary>The joint is not observed (likely due to occlusion), predicted joint pose.</summary>
+        Low = 1,
+
+        /// <summary>Medium confidence in joint pose. Current SDK will only provide joints up to this confidence level.</summary>
+        Medium = 2,
+
+        /// <summary>High confidence in joint pose. Placeholder for future SDK.</summary>
+        High = 3,
+    }
+}
\ No newline at end of file
diff --git a/K4AdotNet/BodyTracking/JointType.cs b/K4AdotNet/BodyTracking/JointType.cs
index 1435481..916be64 100644
--- a/K4AdotNet/BodyTracking/JointType.cs
+++ b/K4AdotNet/BodyTracking/JointType.cs
@@ -11,10 +11,16 @@
     //     K4ABT_JOINT_SHOULDER_LEFT,
     //     K4ABT_JOINT_ELBOW_LEFT,
     //     K4ABT_JOINT_WRIST_LEFT,
+    //     K4ABT_JOINT_HAND_LEFT,
+    //     K4ABT_JOINT_HANDTIP_LEFT,
+    //     K4ABT_JOINT_THUMB_LEFT,
     //     K4ABT_JOINT_CLAVICLE_RIGHT,
     //     K4ABT_JOINT_SHOULDER_RIGHT,
     //     K4ABT_JOINT_ELBOW_RIGHT,
     //     K4ABT_JOINT_WRIST_RIGHT,
+    //     K4ABT_JOINT_HAND_RIGHT,
+    //     K4ABT_JOINT_HANDTIP_RIGHT,
+    //     K4ABT_JOINT_THUMB_RIGHT,
     //     K4ABT_JOINT_HIP_LEFT,
     //     K4ABT_JOINT_KNEE_LEFT,
     //     K4ABT_JOINT_ANKLE_LEFT,
@@ -62,6 +68,15 @@ public enum JointType
         /// <summary>Left wrist joint.</summary>
         WristLeft,
 
+        /// <summary>Left hand joint.</summary>
+        HandLeft,
+
+        /// <summary>Tip of left hand joint.</summary>
+        HandTipLeft,
+
+        /// <summary>Left thumb joint.</summary>
+        ThumbLeft,
+
         /// <summary>Right clavicle joint.</summary>
         ClavicleRight,
 
@@ -74,6 +89,15 @@ public enum JointType
         /// <summary>Right wrist joint.</summary>
         WristRight,
 
+        /// <summary>Right hand joint.</summary>
+        HandRight,
+
+        /// <summary>Tip of right hand joint.</summary>
+        HandTipRight,
+
+        /// <summary>Right thumb joint.</summary>
+        ThumbRight,
+
         /// <summary>Left hip joint.</summary>
         HipLeft,
 
diff --git a/K4AdotNet/BodyTracking/JointTypes.cs b/K4AdotNet/BodyTracking/JointTypes.cs
index defa68c..03f05ff 100644
--- a/K4AdotNet/BodyTracking/JointTypes.cs
+++ b/K4AdotNet/BodyTracking/JointTypes.cs
@@ -19,10 +19,16 @@ public static class JointTypes
             JointType.ShoulderLeft,
             JointType.ElbowLeft,
             JointType.WristLeft,
+            JointType.HandLeft,
+            JointType.HandTipLeft,
+            JointType.ThumbLeft,
             JointType.ClavicleRight,
             JointType.ShoulderRight,
             JointType.ElbowRight,
             JointType.WristRight,
+            JointType.HandRight,
+            JointType.HandTipRight,
+            JointType.ThumbRight,
             JointType.HipLeft,
             JointType.KneeLeft,
             JointType.AnkleLeft,
@@ -66,6 +72,7 @@ public static bool IsFaceFeature(this JointType jointType)
         /// </returns>
         public static bool IsLeft(this JointType jointType)
             => jointType == JointType.ClavicleLeft || jointType == JointType.ShoulderLeft || jointType == JointType.ElbowLeft || jointType == JointType.WristLeft
+                || jointType == JointType.HandLeft || jointType == JointType.HandTipLeft || jointType == JointType.ThumbLeft
                 || jointType == JointType.HipLeft || jointType == JointType.KneeLeft || jointType == JointType.AnkleLeft || jointType == JointType.FootLeft
                 || jointType == JointType.EyeLeft || jointType == JointType.EarLeft;
 
@@ -77,6 +84,7 @@ public static bool IsLeft(this JointType jointType)
         /// </returns>
         public static bool IsRight(this JointType jointType)
             => jointType == JointType.ClavicleRight || jointType == JointType.ShoulderRight || jointType == JointType.ElbowRight || jointType == JointType.WristRight
+                || jointType == JointType.HandRight || jointType == JointType.HandTipRight || jointType == JointType.ThumbRight
                 || jointType == JointType.HipRight || jointType == JointType.KneeRight || jointType == JointType.AnkleRight || jointType == JointType.FootRight
                 || jointType == JointType.EyeRight || jointType == JointType.EarRight;
 
@@ -102,11 +110,19 @@ public static JointType GetParent(this JointType jointType)
                 case JointType.ShoulderLeft: return JointType.ClavicleLeft;
                 case JointType.ElbowLeft: return JointType.ShoulderLeft;
                 case JointType.WristLeft: return JointType.ElbowLeft;
+                // Left hand
+                case JointType.HandLeft: return JointType.WristLeft;
+                case JointType.HandTipLeft: return JointType.HandLeft;
+                case JointType.ThumbLeft: return JointType.WristLeft;
                 // Right arm
                 case JointType.ClavicleRight: return JointType.SpineChest;
                 case JointType.ShoulderRight: return JointType.ClavicleRight;
                 case JointType.ElbowRight: return JointType.ShoulderRight;
                 case JointType.WristRight: return JointType.ElbowRight;
+                // Right hand
+                case JointType.HandRight: return JointType.WristRight;
+                case JointType.HandTipRight: return JointType.HandRight;
+                case JointType.ThumbRight: return JointType.WristRight;
                 // Left leg
                 case JointType.HipLeft: return JointType.Pelvis;
                 case JointType.KneeLeft: return JointType.HipLeft;
@@ -136,26 +152,40 @@ public static JointType Mirror(this JointType jointType)
         {
             switch (jointType)
             {
+                // Left arm -> Right arm
                 case JointType.ClavicleLeft: return JointType.ClavicleRight;
                 case JointType.ShoulderLeft: return JointType.ShoulderRight;
                 case JointType.ElbowLeft: return JointType.ElbowRight;
                 case JointType.WristLeft: return JointType.WristRight;
+                // Left hand -> Right hand
+                case JointType.HandLeft: return JointType.HandRight;
+                case JointType.HandTipLeft: return JointType.HandTipRight;
+                case JointType.ThumbLeft: return JointType.ThumbRight;
+                // Right arm -> Left arm
                 case JointType.ClavicleRight: return JointType.ClavicleLeft;
                 case JointType.ShoulderRight: return JointType.ShoulderLeft;
                 case JointType.ElbowRight: return JointType.ElbowLeft;
                 case JointType.WristRight: return JointType.WristLeft;
+                // Right hand -> Left hand
+                case JointType.HandRight: return JointType.HandLeft;
+                case JointType.HandTipRight: return JointType.HandTipLeft;
+                case JointType.ThumbRight: return JointType.ThumbLeft;
+                // Left leg -> Right leg
                 case JointType.HipLeft: return JointType.HipRight;
                 case JointType.KneeLeft: return JointType.KneeRight;
                 case JointType.AnkleLeft: return JointType.AnkleRight;
                 case JointType.FootLeft: return JointType.FootRight;
                 case JointType.HipRight: return JointType.HipLeft;
+                // Right leg -> Left leg
                 case JointType.KneeRight: return JointType.KneeLeft;
                 case JointType.AnkleRight: return JointType.AnkleLeft;
                 case JointType.FootRight: return JointType.FootLeft;
+                // Face
                 case JointType.EyeLeft: return JointType.EyeRight;
                 case JointType.EarLeft: return JointType.EarRight;
                 case JointType.EyeRight: return JointType.EyeLeft;
                 case JointType.EarRight: return JointType.EarLeft;
+                // Invariant joints
                 default: return jointType;
             }
         }
diff --git a/K4AdotNet/BodyTracking/Skeleton.cs b/K4AdotNet/BodyTracking/Skeleton.cs
index c05c890..a35fe40 100644
--- a/K4AdotNet/BodyTracking/Skeleton.cs
+++ b/K4AdotNet/BodyTracking/Skeleton.cs
@@ -44,6 +44,15 @@ public struct Skeleton : IEnumerable<Joint>
         /// <summary>Left wrist joint.</summary>
         public Joint WristLeft;
 
+        /// <summary>Left hand joint.</summary>
+        public Joint HandLeft;
+
+        /// <summary>Tip of left hand joint.</summary>
+        public Joint HandTipLeft;
+
+        /// <summary>Left thumb joint.</summary>
+        public Joint ThumbLeft;
+
         /// <summary>Right clavicle joint.</summary>
         public Joint ClavicleRight;
 
@@ -56,6 +65,15 @@ public struct Skeleton : IEnumerable<Joint>
         /// <summary>Right wrist joint.</summary>
         public Joint WristRight;
 
+        /// <summary>Right hand joint.</summary>
+        public Joint HandRight;
+
+        /// <summary>Tip of right hand joint.</summary>
+        public Joint HandTipRight;
+
+        /// <summary>Right thumb joint.</summary>
+        public Joint ThumbRight;
+
         /// <summary>Left hip joint.</summary>
         public Joint HipLeft;
 
@@ -121,10 +139,16 @@ public Joint this[JointType index]
                     case JointType.ShoulderLeft: return ShoulderLeft;
                     case JointType.ElbowLeft: return ElbowLeft;
                     case JointType.WristLeft: return WristLeft;
+                    case JointType.HandLeft: return HandLeft;
+                    case JointType.HandTipLeft: return HandTipLeft;
+                    case JointType.ThumbLeft: return ThumbLeft;
                     case JointType.ClavicleRight: return ClavicleRight;
                     case JointType.ShoulderRight: return ShoulderRight;
                     case JointType.ElbowRight: return ElbowRight;
                     case JointType.WristRight: return WristRight;
+                    case JointType.HandRight: return HandRight;
+                    case JointType.HandTipRight: return HandTipRight;
+                    case JointType.ThumbRight: return ThumbRight;
                     case JointType.HipLeft: return HipLeft;
                     case JointType.KneeLeft: return KneeLeft;
                     case JointType.AnkleLeft: return AnkleLeft;
@@ -155,10 +179,16 @@ public Joint this[JointType index]
                     case JointType.ShoulderLeft: ShoulderLeft = value; break;
                     case JointType.ElbowLeft: ElbowLeft = value; break;
                     case JointType.WristLeft: WristLeft = value; break;
+                    case JointType.HandLeft: HandLeft = value; break;
+                    case JointType.HandTipLeft: HandTipLeft = value; break;
+                    case JointType.ThumbLeft: ThumbLeft = value; break;
                     case JointType.ClavicleRight: ClavicleRight = value; break;
                     case JointType.ShoulderRight: ShoulderRight = value; break;
                     case JointType.ElbowRight: ElbowRight = value; break;
                     case JointType.WristRight: WristRight = value; break;
+                    case JointType.HandRight: HandRight = value; break;
+                    case JointType.HandTipRight: HandTipRight = value; break;
+                    case JointType.ThumbRight: ThumbRight = value; break;
                     case JointType.HipLeft: HipLeft = value; break;
                     case JointType.KneeLeft: KneeLeft = value; break;
                     case JointType.AnkleLeft: AnkleLeft = value; break;
diff --git a/K4AdotNet/BodyTracking/TrackerConfiguration.cs b/K4AdotNet/BodyTracking/TrackerConfiguration.cs
index bf6582b..7ac1527 100644
--- a/K4AdotNet/BodyTracking/TrackerConfiguration.cs
+++ b/K4AdotNet/BodyTracking/TrackerConfiguration.cs
@@ -6,6 +6,7 @@ namespace K4AdotNet.BodyTracking
     // typedef struct _k4abt_tracker_configuration_t
     // {
     //     k4abt_sensor_orientation_t sensor_orientation;
+    //     bool cpu_only_mode;
     // } k4abt_tracker_configuration_t;
     //
     /// <summary>Configuration parameters for a k4abt body tracker.</summary>
@@ -18,10 +19,21 @@ public struct TrackerConfiguration
         /// <remarks>Setting the correct orientation can help the body tracker to achieve more accurate body tracking results.</remarks>
         public SensorOrientation SensorOrientation;
 
-        // static const k4abt_tracker_configuration_t K4ABT_TRACKER_CONFIG_DEFAULT = { K4ABT_SENSOR_ORIENTATION_DEFAULT };
+        /// <summary>Specify whether to use CPU only mode or GPU mode to run the tracker.</summary>
+        /// <remarks>
+        /// The CPU only mode doesn't require the machine to have a GPU to run this SDK.
+        /// But it will be much slower than the GPU mode.
+        /// </remarks>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool CpuOnlyMode;
+
+        // static const k4abt_tracker_configuration_t K4ABT_TRACKER_CONFIG_DEFAULT = { K4ABT_SENSOR_ORIENTATION_DEFAULT, false };
         //
         /// <summary>Default configuration setting for k4abt tracker.</summary>
         /// <remarks>Use this setting to initialize a <see cref="TrackerConfiguration"/> to a default state.</remarks>
-        public static readonly TrackerConfiguration Default = new TrackerConfiguration { SensorOrientation = SensorOrientation.Default };
+        public static readonly TrackerConfiguration Default = new TrackerConfiguration {
+            SensorOrientation = SensorOrientation.Default,
+            CpuOnlyMode = false,
+        };
     }
 }
diff --git a/K4AdotNet/K4AdotNet.xml b/K4AdotNet/K4AdotNet.xml
index 5468f6f..3086d0d 100644
--- a/K4AdotNet/K4AdotNet.xml
+++ b/K4AdotNet/K4AdotNet.xml
@@ -274,6 +274,24 @@
         <member name="F:K4AdotNet.BodyTracking.Joint.Orientation">
             <summary>The orientation of the joint specified in normalized quaternion.</summary>
         </member>
+        <member name="F:K4AdotNet.BodyTracking.Joint.ConfidenceLevel">
+            <summary>The confidence level of the joint.</summary>
+        </member>
+        <member name="T:K4AdotNet.BodyTracking.JointConfidenceLevel">
+            <summary>This enumeration specifies the joint confidence level.</summary>
+        </member>
+        <member name="F:K4AdotNet.BodyTracking.JointConfidenceLevel.None">
+            <summary>The joint is out of range (too far from depth camera).</summary>
+        </member>
+        <member name="F:K4AdotNet.BodyTracking.JointConfidenceLevel.Low">
+            <summary>The joint is not observed (likely due to occlusion), predicted joint pose.</summary>
+        </member>
+        <member name="F:K4AdotNet.BodyTracking.JointConfidenceLevel.Medium">
+            <summary>Medium confidence in joint pose. Current SDK will only provide joints up to this confidence level.</summary>
+        </member>
+        <member name="F:K4AdotNet.BodyTracking.JointConfidenceLevel.High">
+            <summary>High confidence in joint pose. Placeholder for future SDK.</summary>
+        </member>
         <member name="T:K4AdotNet.BodyTracking.JointType">
             <summary>Skeleton joint index.</summary>
             <remarks>See https://docs.microsoft.com/en-us/azure/Kinect-dk/body-joints#joint-hierarchy for details.</remarks>
@@ -846,6 +864,13 @@
             <summary>The sensor mounting orientation type.</summary>
             <remarks>Setting the correct orientation can help the body tracker to achieve more accurate body tracking results.</remarks>
         </member>
+        <member name="F:K4AdotNet.BodyTracking.TrackerConfiguration.CpuOnlyMode">
+            <summary>Specify whether to use CPU only mode or GPU mode to run the tracker.</summary>
+            <remarks>
+            The CPU only mode doesn't require the machine to have a GPU to run this SDK.
+            But it will be much slower than the GPU mode.
+            </remarks>
+        </member>
         <member name="F:K4AdotNet.BodyTracking.TrackerConfiguration.Default">
             <summary>Default configuration setting for k4abt tracker.</summary>
             <remarks>Use this setting to initialize a <see cref="T:K4AdotNet.BodyTracking.TrackerConfiguration"/> to a default state.</remarks>
diff --git a/K4AdotNet/Sdk.cs b/K4AdotNet/Sdk.cs
index 3e936bb..77047f8 100644
--- a/K4AdotNet/Sdk.cs
+++ b/K4AdotNet/Sdk.cs
@@ -31,7 +31,7 @@ public static class Sdk
         public const string BODY_TRACKING_DLL_NAME = "k4abt";
 
         /// <summary>Expected version of Body Tracking runtime. This version of K4AdotNet assembly is built and tested against this version of Body Tracking.</summary>
-        public static readonly Version BODY_TRACKING_EXPECTED_VERSION = new Version(0, 9, 3);
+        public static readonly Version BODY_TRACKING_EXPECTED_VERSION = new Version(0, 9, 4);
 
         /// <summary>Name of ONNX runtime library (DLL) which is used by <see cref="BODY_TRACKING_DLL_NAME"/>.</summary>
         /// <remarks>This library is required for Body Tracking part of API (see <c>K4AdotNet.BodyTracking</c> namespace).</remarks>
@@ -224,7 +224,7 @@ private static bool CheckBodyTrackingRuntimeVersion(string bodyTrackingRuntimePa
                 // Do not use FileVersion property as it's not populated under Unity .NET runtime
                 if (fvi != null)
                 {
-                    if (new Version(fvi.FileMajorPart, fvi.FileMinorPart, fvi.FileBuildPart, fvi.FilePrivatePart) >= BODY_TRACKING_EXPECTED_VERSION)
+                    if (new Version(fvi.FileMajorPart, fvi.FileMinorPart, fvi.FileBuildPart) == BODY_TRACKING_EXPECTED_VERSION)
                     {
                         message = null;
                         return true;
@@ -232,7 +232,7 @@ private static bool CheckBodyTrackingRuntimeVersion(string bodyTrackingRuntimePa
                 }
             }
 
-            message = $"Version {BODY_TRACKING_EXPECTED_VERSION} or greater of Body Tracking runtime is expected.";
+            message = $"Version {BODY_TRACKING_EXPECTED_VERSION} of Body Tracking runtime is expected.";
             return false;
         }
 
@@ -270,7 +270,7 @@ private static string GetBodyTrackingRuntimePath(out string message)
             if (ProbePathForBodyTrackingRuntime(sdkBinDir))
                 return sdkBinDir;
 
-            message = "Cannot find Body Tracking runtime or some of its components (neither in application directory, nor in Body Tracking SDK directory).";
+            message = $"Cannot find Body Tracking {BODY_TRACKING_EXPECTED_VERSION} runtime or some of its components (neither in application directory, nor in Body Tracking SDK directory).";
             return null;
         }
 
diff --git a/README.md b/README.md
index 0b160c9..96f8aaa 100644
--- a/README.md
+++ b/README.md
@@ -49,9 +49,9 @@
 
 | Library "component" | Depends on                                   | Version in use | Location in repository                | Included in [NuGet package](https://www.nuget.org/packages/K4AdotNet) 
 |---------------------|----------------------------------------------|----------------|---------------------------------------|--------------------------
-| Sensor API          | `k4a.dll`, `depthengine_2_0.dll`<sup>(1)</sup> | 1.2.0          | `externals/k4a/windows-desktop/amd64` | YES
-| Record API          | `k4arecord.dll`                              | 1.2.0          | `externals/k4a/windows-desktop/amd64` | YES
-| Body Tracking API   | `k4abt.dll`<sup>(2)</sup>, `dnn_model_2_0.onnx`   | 0.9.3          |                                       | no<sup>(3)</sup>
+| Sensor API          | `k4a.dll`, `depthengine_2_0.dll`<sup>(1)</sup> | 1.3.0          | `externals/k4a/windows-desktop/amd64` | YES
+| Record API          | `k4arecord.dll`                              | 1.3.0          | `externals/k4a/windows-desktop/amd64` | YES
+| Body Tracking API   | `k4abt.dll`<sup>(2)</sup>, `dnn_model_2_0.onnx`   | 0.9.4          |                                       | no<sup>(3)</sup>
 
 Notes:
 * <sup>(1)</sup> `depthengine_2_0.dll` is required only if you are using `Transformation` or `Device` classes. All other Sensor API (types from `K4AdotNet.Sensor` namespace) depends only on `k4a.dll`.
diff --git a/externals/k4abt/include/k4abttypes.h b/externals/k4abt/include/k4abttypes.h
index f7e663e..697c84d 100644
--- a/externals/k4abt/include/k4abttypes.h
+++ b/externals/k4abt/include/k4abttypes.h
@@ -64,10 +64,16 @@ typedef enum
     K4ABT_JOINT_SHOULDER_LEFT,
     K4ABT_JOINT_ELBOW_LEFT,
     K4ABT_JOINT_WRIST_LEFT,
+    K4ABT_JOINT_HAND_LEFT,
+    K4ABT_JOINT_HANDTIP_LEFT,
+    K4ABT_JOINT_THUMB_LEFT,
     K4ABT_JOINT_CLAVICLE_RIGHT,
     K4ABT_JOINT_SHOULDER_RIGHT,
     K4ABT_JOINT_ELBOW_RIGHT,
     K4ABT_JOINT_WRIST_RIGHT,
+    K4ABT_JOINT_HAND_RIGHT,
+    K4ABT_JOINT_HANDTIP_RIGHT,
+    K4ABT_JOINT_THUMB_RIGHT,
     K4ABT_JOINT_HIP_LEFT,
     K4ABT_JOINT_KNEE_LEFT,
     K4ABT_JOINT_ANKLE_LEFT,
@@ -114,6 +120,13 @@ typedef struct _k4abt_tracker_configuration_t
      * Setting the correct orientation can help the body tracker to achieve more accurate body tracking results
      */
     k4abt_sensor_orientation_t sensor_orientation;
+
+    /** Specify whether to use CPU only mode or GPU mode to run the tracker.
+     *
+     * The CPU only mode doesn't require the machine to have a GPU to run this SDK. But it will be much slower 
+     * than the GPU mode.
+     */
+    bool cpu_only_mode;
 } k4abt_tracker_configuration_t;
 
 /**
@@ -143,6 +156,21 @@ typedef union
     float v[4];  /**< Array representation of a quaternion */
 } k4a_quaternion_t;
 
+/** k4abt_joint_confidence_level_t
+ *
+ * \remarks
+ * This enumeration specifies the joint confidence level.
+
+ */
+typedef enum
+{
+    K4ABT_JOINT_CONFIDENCE_NONE = 0,          /**< The joint is out of range (too far from depth camera) */
+    K4ABT_JOINT_CONFIDENCE_LOW = 1,           /**< The joint is not observed (likely due to occlusion), predicted joint pose */
+    K4ABT_JOINT_CONFIDENCE_MEDIUM = 2,        /**< Medium confidence in joint pose. Current SDK will only provide joints up to this confidence level */
+    K4ABT_JOINT_CONFIDENCE_HIGH = 3,          /**< High confidence in joint pose. Placeholder for future SDK */
+    K4ABT_JOINT_CONFIDENCE_LEVELS_COUNT = 4,  /**< The total number of confidence levels. */
+} k4abt_joint_confidence_level_t;
+
 /** Structure to define a single joint
  *
  * The position and orientation together defines the coordinate system for the given joint. They are defined relative
@@ -152,6 +180,7 @@ typedef struct _k4abt_joint_t
 {
     k4a_float3_t     position;    /**< The position of the joint specified in millimeters*/
     k4a_quaternion_t orientation; /**< The orientation of the joint specified in normalized quaternion*/
+    k4abt_joint_confidence_level_t confidence_level; /**< The confidence level of the joint*/
 } k4abt_joint_t;
 
 /** Structure to define joints for skeleton
@@ -198,7 +227,8 @@ typedef struct _k4abt_body_t
  * \remarks
  * Use this setting to initialize a \ref k4abt_tracker_configuration_t to a default state.
  */
-static const k4abt_tracker_configuration_t K4ABT_TRACKER_CONFIG_DEFAULT = { K4ABT_SENSOR_ORIENTATION_DEFAULT };
+static const k4abt_tracker_configuration_t K4ABT_TRACKER_CONFIG_DEFAULT = { K4ABT_SENSOR_ORIENTATION_DEFAULT, // sensor_orientation
+                                                                            false };                          // use_cpu_only_mode
 
 /**
  * @}
diff --git a/externals/k4abt/include/k4abtversion.h b/externals/k4abt/include/k4abtversion.h
index 4607fb9..63d3ff0 100644
--- a/externals/k4abt/include/k4abtversion.h
+++ b/externals/k4abt/include/k4abtversion.h
@@ -6,11 +6,11 @@
 
 #define K4ABT_VERSION_MAJOR           0
 #define K4ABT_VERSION_MINOR           9
-#define K4ABT_VERSION_PATCH           3
+#define K4ABT_VERSION_PATCH           4
 #define K4ABT_VERSION_PRERELEASE      ""
 #define K4ABT_VERSION_BUILD_METADATA  ""
 
-#define K4ABT_VERSION_STR             "0.9.3"
+#define K4ABT_VERSION_STR             "0.9.4"
 
 #define K4ABT_DNN_MODEL_FILE          "dnn_model_2_0.onnx"