private HitTestResultBehavior HitTestCallback(HitTestResult result)
 {
     var rayhit = result as RayHitTestResult;
     hitTestValue = rayhit.PointHit;
     hit = true;
     return HitTestResultBehavior.Continue;
 }

 HitTestResultBehavior HitTest(HitTestResult ht)
 {
     var r = ht as RayMeshGeometry3DHitTestResult;
     if (r == null) return HitTestResultBehavior.Continue;
     svr.Move(bFirst, r.PointHit.X < (svr.BarPos(bFirst) - 0.5 + barRate / 2) * 300);
     return HitTestResultBehavior.Stop;
 }

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

                if (rayMeshResult != null)
                {
                    GeometryModel3D hitgeo = rayMeshResult.ModelHit as GeometryModel3D;
                    DiffuseMaterial dm = hitgeo.Material as DiffuseMaterial;
                    SolidColorBrush b = dm.Brush as SolidColorBrush;
                    Color c = b.Color;
                    c.ScB = 1 - c.ScB;
                    c.ScG = 1 - c.ScG;
                    c.ScR = 1 - c.ScR;
                    hitgeo.Material = new DiffuseMaterial(new SolidColorBrush(c));
                }
            }

            return HitTestResultBehavior.Continue;
        }

        private HitTestResultBehavior SelectModel(HitTestResult result)
        {
            RayHitTestResult res = result as RayHitTestResult;
            if (res != null)
            {
                DependencyObject visual = res.VisualHit;
                object model = null, scene = null;
                while (visual != null)
                {
                    if (consoleMode)
                    {
                        if (visual is Model)
                            scope.SetVariable("model", model = visual);
                        else if (visual is Scene)
                            scope.SetVariable("scene", scene = visual);
                    }
                    else
                        Control.SendClick(visual, result);
                    visual = VisualTreeHelper.GetParent(visual);
                }
                selection.Text = $"Selection: {model} in {scene}";
            }

            return HitTestResultBehavior.Stop;
        }

 public HitTestResultBehavior MainHitTestResult(HitTestResult result)
 {
     if ((result.VisualHit as DrawingVisual) != null)
     {
         hittedElements.Add(result.VisualHit as DrawingVisual);
     }
     return HitTestResultBehavior.Continue;
 }

        HitTestResultBehavior InfoHitTestSelOneResultCallback(HitTestResult result) {
            var frameworkElement = result.VisualHit as FrameworkElement;

            if (frameworkElement == null)
                return HitTestResultBehavior.Continue;

            _infoShape = frameworkElement;
            return HitTestResultBehavior.Stop;
        }

        HitTestResultBehavior RailHitTestSelOneResultCallback(HitTestResult result) {
            var frameworkElement = result.VisualHit as FrameworkElement;

            if (frameworkElement == null || !(frameworkElement.Tag is Rail))
                return HitTestResultBehavior.Continue;

            _railUnderMouse = frameworkElement.Tag as Rail;
            return HitTestResultBehavior.Stop;
        }

        // If a child visual object is hit, toggle its opacity to visually indicate a hit.
        public HitTestResultBehavior MyCallback(HitTestResult result)
        {
            if (result.VisualHit.GetType() == typeof (System.Windows.Media.DrawingVisual))
            {
                ((System.Windows.Media.DrawingVisual) result.VisualHit).Opacity =
                    ((System.Windows.Media.DrawingVisual) result.VisualHit).Opacity == 1.0 ? 0.4 : 1.0;
            }

            // Stop the hit test enumeration of objects in the visual tree.
            return HitTestResultBehavior.Stop;
        }

 // Return the result of the hit test to the callback.
 public HitTestResultBehavior PerformHitTest(HitTestResult result)
 {
     FrameworkElement visual = (FrameworkElement)result.VisualHit;
     // Add the hit test result to the list that will be processed after the enumeration.
     if (visual.IsHitTestVisible)
         hitTestResults.Add(visual);
     else
         return HitTestResultBehavior.Stop;
     // Set the behavior to return visuals at all z-order levels.
     return HitTestResultBehavior.Continue;
 }

 private HitTestResultBehavior HitTestCallback(HitTestResult result)
 {
     GeometryHitTestResult geometryResult = (GeometryHitTestResult)result;
     DrawingVisual visual = result.VisualHit as DrawingVisual;
     if (visual != null &&
         geometryResult.IntersectionDetail == IntersectionDetail.FullyInside)
     {
         hits.Add(visual);
     }
     return HitTestResultBehavior.Continue;
 }

        protected HitTestResultBehavior OnVisualHit(HitTestResult result)
        {
            foreach (NameValuePair nvp in dataPoints)
            {
                if (nvp.Tag == result.VisualHit)
                {
                    MessageBox.Show("Name: " + nvp.Name + ", Value: " + nvp.Value.ToString());
                    break;
                }
            }

            return HitTestResultBehavior.Continue;
        }

        // Handle the hit test results enumeration in the callback.
        internal static HitTestResultBehavior CircleHitTestResult(HitTestResult result)
        {
            // Add the hit test result to the list that will be processed after the enumeration.
            HitResultsList.Add(result.VisualHit);

            // Determine whether hit test should return only the top-most layer visual.
            if (MyWindow.TopmostLayer)
            {
                // Set the behavior to stop the enumeration of visuals.
                return HitTestResultBehavior.Stop;
            }
            // Set the behavior to continue the enumeration of visuals.
            // All visuals that intersect at the hit test coordinates are returned,
            // whether visible or not.
            return HitTestResultBehavior.Continue;
        }

        // Return the result of the hit test to the callback. 
        public HitTestResultBehavior MyHitTestResult(HitTestResult result)
        {
            if (result.VisualHit is FrameworkElement)
            {
                if (((FrameworkElement) result.VisualHit).DataContext is Appraisal)
                {
                    hitResultsList.Add(((FrameworkElement)result.VisualHit).DataContext as Appraisal);
                }
            }
                
            // Add the hit test result to the list that will be processed after the enumeration.
            

            // Set the behavior to return visuals at all z-order levels. 
            return HitTestResultBehavior.Stop;
        }

        // If a child visual object is hit, toggle its opacity to visually indicate a hit.
        public HitTestResultBehavior myCallback(HitTestResult result)
        {
            if (result.VisualHit.GetType() == typeof(DrawingVisual))
            {
                if (((DrawingVisual)result.VisualHit).Opacity == 1.0)
                {
                    ((DrawingVisual)result.VisualHit).Opacity = 0.4;
                }
                else
                {
                    ((DrawingVisual)result.VisualHit).Opacity = 1.0;
                }
            }

            // Stop the hit test enumeration of objects in the visual tree.
            return HitTestResultBehavior.Stop;
        }

        public HitTestResultBehavior myCallback(HitTestResult result)
        {
            // Toggle between a skewed rendering and normal rendering,
            // if a visual was clicked.
            if (result.VisualHit.GetType() == typeof(DrawingVisual))
            {
                if (((DrawingVisual)result.VisualHit).Transform == null)
                {
                    ((DrawingVisual)result.VisualHit).Transform = new SkewTransform(7, 7);
                }
                else
                {
                    ((DrawingVisual)result.VisualHit).Transform = null;
                }
            }

            // Tell HitTest() to stop drilling into the visual tree.
            return HitTestResultBehavior.Stop;
        }

        HitTestResultBehavior NodeOrRailHitTestSelOnlyOneNodeCallback(HitTestResult result) {
            var frameworkElement = result.VisualHit as FrameworkElement;

            if (!(frameworkElement is Path))
                return HitTestResultBehavior.Continue;
            object tag = frameworkElement.Tag;
            if (tag != null) {
                GraphmapsNode graphmapsNode = tag as GraphmapsNode;
                if (graphmapsNode != null) {
                    _nodeUnderMouse = graphmapsNode;
                    return HitTestResultBehavior.Stop;
                }
                else {
                    var rail = frameworkElement.Tag as Rail;
                    if (rail != null)
                        _railUnderMouse = rail;
                }
            }

            return HitTestResultBehavior.Continue;
        }

 // Return the result of the hit test to the callback.
 private static HitTestResultBehavior hitTestResultCallback(HitTestResult result)
 {
     // Retrieve the results of the hit test.
     IntersectionDetail intersectionDetail = ((GeometryHitTestResult)result).IntersectionDetail;
     switch (intersectionDetail)
     {
         case IntersectionDetail.FullyContains:
             // Add the hit test result to the list that will be processed after the enumeration.
             hitResultsList.Add(result.VisualHit);
             return HitTestResultBehavior.Continue;
         case IntersectionDetail.Intersects:
             hitResultsList.Add(result.VisualHit);
             // Set the behavior to return visuals at all z-order levels.
             return HitTestResultBehavior.Continue;
         case IntersectionDetail.FullyInside:
             hitResultsList.Add(result.VisualHit);
             // Set the behavior to return visuals at all z-order levels.
             return HitTestResultBehavior.Continue;
         default:
             return HitTestResultBehavior.Stop;
     }
 }

 HitTestResultBehavior HitTestResultCallback(HitTestResult res)
 {
     return HitTestResultBehavior.Continue;
 }

        private HitTestResultBehavior DirectHitTestCallback(HitTestResult result)
        {
            if (null != result && (null != result.VisualHit))
            {
                hitResultsList.Add(result.VisualHit);
                return HitTestResultBehavior.Stop;
            }

            return HitTestResultBehavior.Continue;
        }

        private HitTestResultBehavior VisualCallback(HitTestResult result)
        {
            if (result == null || result.VisualHit == null)
                throw new ArgumentNullException();

            if (result.VisualHit.GetType() == typeof(Grid))
                hitResultsList.Add(result.VisualHit);

            return HitTestResultBehavior.Continue;
        }