title: Fourth row of VP Matrix
body: <p>If have a quesstion regarding matrix multiplication.
  What's the information stored in the fourth row of a View Projection Matrix?
  I thought rotation and scaling information is stored in the upper 3x3 Matrix, translation then in the fourth column with the last element set to 1.
  Im struggling because i get following results for my VP Matrix:</p>
  
  <p>When applying no rotation and no translation (note all values are rounded): </p>
  
  <pre><code>0.34 0 0 0
  0 0.61 0 0
  0 0 -1 -0.2
  0 0 -1 0
  </code></pre>
  
  <p>Applying translation by -100:</p>
  
  <pre><code>0.34 0 0 0
  0 0.61 0 -61.73
  0 0 -1 -0.2
  0 0 -1 0
  </code></pre>
  
  <p>Translation by -100, then rotate 30° on positive X-Axis, afterwards rotate 180° on positive Y-Axis:</p>
  
  <pre><code>-0.34 0 -3 0
  0 0.53 0.3 -53.46
  0 -0.5 0.86 49.8
  0 -0.5 0.8 50
  </code></pre>
  
  <p>It doesnt look right to me. The funny part: It works. So whats the information of this line? </p>
  
  <pre><code>0 -0.5 0.8 50
  </code></pre>
  
  <p>Thanks for helping!</p>