Rotating WPF Content in 3D Space

<UserControl 
  x:Class="ContentControl3D_Demo.Samples.AnimationLengthSample"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:thriple="http://thriple.codeplex.com/"
  >
  
  <UserControl.Background>
    <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
      <GradientStop Color="#CC000000" Offset="0" />
      <GradientStop Color="#44000000" Offset="1" />
    </LinearGradientBrush>
  </UserControl.Background>
  
  <UserControl.Resources>
    <DataTemplate x:Key="ImageButtonTemplate">
      <Button 
        Command="thriple:ContentControl3D.RotateCommand"
        Content="{TemplateBinding Content}" 
        Cursor="Hand" 
        Width="480" Height="360"
        >
        <Button.Template>
          <ControlTemplate TargetType="{x:Type Button}">
            <Border BorderBrush="#CC000000" BorderThickness="8" Background="DarkGray" Padding="1">
              <Image Source="{Binding}" Stretch="Fill" />
            </Border>
          </ControlTemplate>
        </Button.Template>
      </Button>
    </DataTemplate>
  </UserControl.Resources>

  <DockPanel>
    <Border 
      DockPanel.Dock="Bottom" 
      Background="LightGray"
      BorderBrush="Gray"
      BorderThickness="1"
      CornerRadius="6"
      Margin="3"
      Padding="3"
      >
      <DockPanel>
        <TextBlock DockPanel.Dock="Left" Text="Animation Length: " VerticalAlignment="Center" />
        <TextBlock 
          DockPanel.Dock="Right" 
          Text="{Binding ElementName=cntCtrl3D, Path=AnimationLength}" 
          VerticalAlignment="Center" 
          />
        <Slider 
          Minimum="10" Maximum="2000"
          Value="{Binding ElementName=cntCtrl3D, Path=AnimationLength}" 
          />
      </DockPanel>
    </Border>
    
    <thriple:ContentControl3D 
      x:Name="cntCtrl3D"
      BackContent="Images/HawaiianBay.jpg"
      BackContentTemplate="{StaticResource ImageButtonTemplate}"
      Content="Images/HawaiianBayAtSunrise.jpg" 
      ContentTemplate="{StaticResource ImageButtonTemplate}"
      MaxWidth="600" MaxHeight="600"
      />
  </DockPanel>
</UserControl>