viewとviewModelの連携

参考サイトを見て仮想化しないでも速いCanvasを実装したのですが、
viewとviewModelの連携をどうすれば良いか分かりません。
viewModelからcanvasを操作する方法が分かる方がいらしたら教えてください。

c#
1<Window x:Class="FastCanvas.MainWindow"
2        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4        xmlns:local="clr-namespace:FastCanvas"
5        Title="MainWindow">
6    <ScrollViewer HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible">
7        <local:Canvas x:Name="_canvas" Width="3200" Height="32000"></local:Canvas>
8    </ScrollViewer>
9</Window>

c#
1using System.Windows;
2using System.Windows.Media;
3using System.ComponentModel;
4using System.Collections.ObjectModel;
5
6namespace FastCanvas
7{
8    public class Canvas : FrameworkElement
9    {
10        public static Point GetLocation(DependencyObject obj)
11        {
12            return (Point)obj.GetValue(LocationProperty);
13        }
14
15        public static void SetLocation(DependencyObject obj, Point value)
16        {
17            obj.SetValue(LocationProperty, value);
18        }
19        public static readonly DependencyProperty LocationProperty =
20            DependencyProperty.RegisterAttached("Location", typeof(Point), typeof(Canvas),
21            new FrameworkPropertyMetadata(default(Point),FrameworkPropertyMetadataOptions.AffectsArrange));
22
23        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
24        public ObservableCollection<UIElement> Children{get; private set;}
25
26        public Canvas()
27        {
28            Children = new ObservableCollection<UIElement>();
29
30            Children.CollectionChanged += Children_CollectionChanged;
31        }
32
33        void Children_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
34        {
35            if(e.OldItems != null)
36            {
37                foreach (UIElement oldItem in e.OldItems)
38                {
39                    RemoveVisualChild(oldItem);
40                }
41            }
42            if(e.NewItems != null)
43            {
44                foreach (UIElement newItem in e.NewItems)
45                {
46                    AddVisualChild(newItem);
47                }
48            }
49        }
50
51        protected override int VisualChildrenCount
52        {
53            get
54            {
55                return Children.Count;
56            }
57        }
58
59        protected override Visual GetVisualChild(int index)
60        {
61            return Children[index];
62        }
63
64        protected override Size ArrangeOverride(Size finalSize)
65        {
66            foreach(var child in Children)
67            {
68                var location = GetLocation(child);
69
70                child.Arrange(new Rect(location, child.DesiredSize));
71            }
72
73            return base.ArrangeOverride(finalSize);
74        }
75
76        protected override Size MeasureOverride(Size availableSize)
77        {
78            foreach (var child in Children)
79            {
80                var fe = child as FrameworkElement;
81
82                if( fe != null )
83                {
84                    child.Measure(new Size(fe.Width,fe.Height));
85                }
86            }
87
88            return base.MeasureOverride(availableSize);
89        }
90    }
91}