WPF 3 D Coordinate System with A Camera: Example

Then we can map 2D Texture to 3D using MeshGeometry3D

       <Viewport3D>
            <Viewport3D.Camera>
                <PerspectiveCamera Position="-20,46,0" UpDirection="0,0,1" LookDirection="4,-10,0" NearPlaneDistance="0"/>
            ......
                    <GeometryModel3D.Geometry>
                      <MeshGeometry3D  Positions="-10,-10,-10  10,-10,-10  10,10,-10  -10,10,-10  -10,-10,10  -10,10,10"
                          TriangleIndices="0 2 3  0 1 2   0 4 3  4 5 3" 
                               TextureCoordinates="0,0  0,1  1,1  1,0" />