title: Performance problem when applying a RenderTransform to a Viewport3d in WPF
body: <p>I have implemented zooming and panning in my WPF app using a RenderTranform combining scaling and translations. </p>
  
  <p>Everything is peachy with bitmaps, text, graphic paths, shapes and more. 
  As soon as I put a viewport3d in the visual tree and I zoom into the picture, performance drops to terrible (non-interactive!) levels.</p>
  
  <p>Any suggestions? </p>
  
  <p>I have already read this page <a href="http://msdn.microsoft.com/en-us/library/bb613553.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/bb613553.aspx</a> and followed all recommendations applicable to my app. That allowed me to zoom in a bit deeper in the view but not enough...</p>