MDLViewer.xaml

<UserControl x:Class="MDLUtility2.MDLViewer"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Height="402" Width="363"  Background="Gray">
    <Grid x:Name="mainGrid" ShowGridLines="True">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"></ColumnDefinition>
            <ColumnDefinition MaxWidth="0"></ColumnDefinition>
            <ColumnDefinition Width="auto"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
            <Grid x:Name="myGrid" Grid.Column="0" MouseMove="mainViewport_MouseMove" MouseWheel="mainViewport_MouseWheel"  Focusable="True" MouseUp="UserControl_MouseUp">
                <Viewport3D Name="mainViewport" ClipToBounds="True" Focusable="True" IsHitTestVisible="True" DockPanel.Dock="Top">
                    <Viewport3D.Camera>
                        <PerspectiveCamera 
	                          LookDirection="-11,-10,-9"
	                          UpDirection="0,1,0"
	                          Position="11,10,9" 
	                          FieldOfView="70" />
                    </Viewport3D.Camera> 
                <Viewport3D.Children>
                    <ModelVisual3D x:Name="lightsModel">
                        <ModelVisual3D.Children>
                            <ModelVisual3D>
                                <ModelVisual3D.Content>
                                    <AmbientLight x:Name="ambLight" Color="DarkGray"/>
                                </ModelVisual3D.Content>                            
                                </ModelVisual3D>
                            <ModelVisual3D>
                                <ModelVisual3D.Content>
                                    <DirectionalLight x:Name="dirLight" Color="White" Direction="0,-1,-1" />
                                </ModelVisual3D.Content>
                            </ModelVisual3D>
                        </ModelVisual3D.Children>
                    </ModelVisual3D>
                </Viewport3D.Children>
            </Viewport3D>
            </Grid>
        <Canvas x:Name="hiddenCanvas" Grid.Column="1">
                <ScrollViewer x:Name="scrollToolBox" Visibility="Hidden"  Canvas.Top="3" Canvas.Right="22" Height="{Binding ElementName=hiddenCanvas,Path=Height}" VerticalScrollBarVisibility="Auto" Background="Silver">
                    <StackPanel x:Name="stackToolBox">
                        <Expander x:Name="expanderGroups" Header="Display Elements">
                            <StackPanel>
                                <CheckBox x:Name="chkLights" Checked="chkLights_Checked" Unchecked="chkLights_Checked">Lights</CheckBox>
                                <CheckBox x:Name="chkGarages" Checked="chkGarages_Checked" Unchecked="chkGarages_Checked">Garages</CheckBox>
                                <CheckBox x:Name="chkOther" Checked="chkOther_Checked" Unchecked="chkOther_Checked">Hardpoints</CheckBox>
                                <CheckBox x:Name="chkBackground" Checked="chkBackground_Checked" Unchecked="chkBackground_Checked">Background</CheckBox>
                                
                            </StackPanel>                            
                    </Expander>
                    </StackPanel>
                </ScrollViewer>            
        </Canvas>
        <Canvas x:Name="SideBar" Grid.Column="2">            
             <StackPanel x:Name="ButtonPanel" Canvas.Top="0" Canvas.Right="0" >
            <ToggleButton x:Name="btnToolBox"  Checked="btnToolBox_Checked" Unchecked="btnToolBox_Unchecked">
                ToolBox
                <ToggleButton.LayoutTransform>
                    <RotateTransform  Angle="90"></RotateTransform>
                </ToggleButton.LayoutTransform>
            </ToggleButton>            
        </StackPanel>
        </Canvas>
       
    </Grid>
        
</UserControl>