title: How to draw diamond in wpf GeometryModel3D?
body: <p>I am unable to draw the correct shape of diamond.</p>
  <pre><code>        0,1,0
      -1,0,-1 1,0,-1
      -1,0, 1 1,0, 1
          0,-1,0
  </code></pre>
  <p>This is my approach for the diamond top point (0 1 0) and bottom point (0 -1 0) and the a square in between at y = 0. and then connecting them all with <code>TriangleIndices</code>.</p>
  <p>My Code:</p>
  <pre><code>&lt;MeshGeometry3D x:Key=&quot;diamond&quot;
                                  Positions=&quot;
                                         0, 1, 0  
                                         -1, 0,-1    1, 0,-1
                                         -1, 0, 1    1, 0, 1
                                         -1, 0,-1   -1, 0, 1
                                          1, 0, 1    1, 0,-1
                                         0,-1, 0  
                                        &quot;
                                  TriangleIndices=&quot;
                                         0  1  2     0  3  4
                                         0  5  6     0  7  8
                                         9  1  2     9  3  4
                                         9  5  6     9  7  8
                                         1  2  3     4  5  6
                                         7  8  9     1  2  5
                                         5  6  8     1  2  4
                                         1  2  6     1  2  8
                                         5  6  7     1  5  6
                                         1  3  5     0  2  3
                                         &quot; /&gt;
  </code></pre>
  <p>This is my final result for the image</p>
  <p><a href="https://i.stack.imgur.com/f8CVM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/f8CVM.png" alt="enter image description here" /></a>
  <a href="https://i.stack.imgur.com/Aqzmw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Aqzmw.png" alt="" /></a></p>
  <p>As you can see not all triangles are drawn and I don't know why. I know I have added alot of TriangleIndices in the XAML properties but still there is no full diamond.</p>