public void OnDragging(ViewControl vc, Point scrPt)
        {
            m_hasHoverPt = HitTest(out m_hoverPt, scrPt, vc);
            if (!m_hasHoverPt)
            {
                return;
            }

            var nativeVC = vc as GUILayer.IViewContext;

            if (nativeVC == null)
            {
                return;
            }

            var game = vc.As <DesignViewControl>().DesignView.Context.As <IGame>();

            if (game == null)
            {
                return;
            }

            if (ManipulatorContext.Objects.Count == 0)
            {
                return;
            }

            GUILayer.EditorInterfaceUtils.ScatterPlaceOperation op;

            var sceneManager = nativeVC.SceneManager;

            using (var editor = sceneManager.GetPlacementsEditor())
            {
                using (var scene = sceneManager.GetIntersectionScene())
                {
                    op = GUILayer.EditorInterfaceUtils.CalculateScatterOperation(
                        editor, scene,
                        ManipulatorContext.Objects.Select(C => _assetService.AsAssetName(new Uri(C.Model))),
                        XLEBridgeUtils.Utils.AsVector3(m_hoverPt),
                        ManipulatorContext.Radius, ManipulatorContext.Density);
                }
            }

            foreach (var d in op._toBeDeleted)
            {
                var adapter = m_nativeIdMapping.GetAdapter(d.Item1, d.Item2).As <DomNodeAdapter>();
                if (adapter != null)
                {
                    adapter.DomNode.RemoveFromParent();
                }
            }

            var resourceResolvers = Globals.MEFContainer.GetExportedValues <IResourceResolver>();
            var resourceConverter = Globals.MEFContainer.GetExportedValue <ResourceConverterService>();

            foreach (var s in op._creationPositions)
            {
                // select a random entry from the list of objects
                var o = ManipulatorContext.SelectRandomObject(m_rng);

                IResource resource = null;
                foreach (var d in resourceResolvers)
                {
                    resource = d.Resolve(new Uri(
                                             new Uri(System.Environment.CurrentDirectory + "\\"),
                                             o.Model + "<model"));
                    if (resource != null)
                    {
                        break;
                    }
                }

                if (resource != null)
                {
                    var resGob = resourceConverter.Convert(resource);
                    if (resGob != null)
                    {
                        resGob.As <DomNode>().InitializeExtensions();

                        var hierarchical = game.AsAll <IHierarchical>();
                        foreach (var h in hierarchical)
                        {
                            if (h.AddChild(resGob))
                            {
                                break;
                            }
                        }

                        var transform = resGob.As <LevelEditorCore.ITransformable>();
                        transform.Translation = XLEBridgeUtils.Utils.AsVec3F(s);
                        transform.Rotation    = new Sce.Atf.VectorMath.Vec3F(0.0f, 0.0f, (float)(m_rng.NextDouble()) * 2.0f * 3.14159f);

                        // set the material name (if we can)
                        var p = resGob.As <Placements.XLEPlacementObject>();
                        if (p != null)
                        {
                            p.Material    = new Uri(o.Material);
                            p.Supplements = o.Supplements;
                        }
                    }
                }
            }
        }