XAML początki rysowania 3d

Witam, mam mały problem w xamlu, chciałbym narysować sobie trójkąt (później zrobię z tego prostokąt) o współrzędnych 0,0,0 0,0,-5 5,0,-5 pozycję kamery mam ustawioną na 0,20,0 a patrzę w kierunku 0,-1,0. Nie wiem dlaczego nie widać narysowanego trójkąta, może ktoś pomoże

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
    <DockPanel>
        <Viewbox>
            <Canvas Width="600" Height="201">

                <!-- The Viewport3D provides a rendering surface for 3-D visual content. -->
                <Viewport3D Name="MyAnimatedObject"
          ClipToBounds="True" Width="600" Height="150"
          Canvas.Left="0" Canvas.Top="10">

                    <!-- Defines the camera used to view the 3D object. -->
                    <Viewport3D.Camera>
                        <PerspectiveCamera x:Name="myPerspectiveCamera" Position="0,20,0" LookDirection="0,-1,0" 
             FieldOfView="60" />
                    </Viewport3D.Camera>

                    <!-- The ModelVisual3D children contain the 3D models -->
                    <Viewport3D.Children>

                        <!-- This ModelVisual3D defines the light cast in the scene. Without light, the
                 3D object cannot be seen. -->
                        <ModelVisual3D>
                            <ModelVisual3D.Content>
                                <DirectionalLight Color="#FFFFFF" Direction="-0.612372,-0.5,-0.612372" />
                            </ModelVisual3D.Content>
                        </ModelVisual3D>
                        <ModelVisual3D>
                            <ModelVisual3D.Content>
                                <GeometryModel3D>

                                    <!-- The geometry specifes the shape of the 3D plane. In this case, a flat sheet is created. -->
                                    <GeometryModel3D.Geometry>
                                        <MeshGeometry3D
                    
                    
                     
                     Positions="0,0,0 0,0,-5 5,0,-5 " />
                                    </GeometryModel3D.Geometry>

                                    <!-- The material specifies the material applied to the plane. In this case it is a linear gradient.-->
                                    <GeometryModel3D.Material>
                                        <MaterialGroup>
                                            <DiffuseMaterial>
                                                <DiffuseMaterial.Brush>
                                                    <SolidColorBrush Color="Cyan" Opacity="0.3"/>
                                                </DiffuseMaterial.Brush>
                                            </DiffuseMaterial>
                                        </MaterialGroup>
                                    </GeometryModel3D.Material>
                                    <!-- The Transform specifies how to transform the 3D object. The OffsetX property is animated
                       in the Storyboard below. -->
                                    <GeometryModel3D.Transform>
                                        <TranslateTransform3D x:Name="myTranslateTransform3D" OffsetX="0" OffsetY="0" OffsetZ="0" />
                                    </GeometryModel3D.Transform>
                                </GeometryModel3D>
                            </ModelVisual3D.Content>
                        </ModelVisual3D>
                    </Viewport3D.Children>
                    <!-- Trigger the TranslateTransform3D animation when the 3D object loads. -->
                    <Viewport3D.Triggers>
                        <EventTrigger RoutedEvent="Viewport3D.Loaded">
                            <BeginStoryboard>
                                <Storyboard>

                                    <!-- This animation animates the OffsetX property of the TranslateTransform3D. -->
                                    <DoubleAnimation
                   Storyboard.TargetName="myTranslateTransform3D" 
                   Storyboard.TargetProperty="OffsetX" 
                   To="-0.8" 
                   AutoReverse="True" RepeatBehavior="Forever" />

                                    <!-- If you want to animate OffsetY and/or OffsetZ, create similar DoubleAnimations
                       respectively. -->

                                </Storyboard>
                            </BeginStoryboard>
                        </EventTrigger>
                    </Viewport3D.Triggers>
                </Viewport3D>
            </Canvas>
        </Viewbox>
    </DockPanel>
</Page>

Problem rozwiązany look direction był źle ustawiony.