title: Fetching the vertices from the backbuffer (HLSL) on XNA
body: <p>Hello and sorry for the obscure title :}
  I`ll try to explain the best i can.</p>
  
  <p>First of all, i am new to HLSL but i understand about the pipeline and stuff that are from the fairy world. What i`m trying to do is use the gpu for general computations (GPGPU).</p>
  
  <p>What i don`t know is: how can i read* the vertices (that have been transformed using vertex shaders) back to my xna application? I read something about using the texture memory of the gpu but i can't find anything solid...</p>
  
  <p>Thanks in advance for any info/tip! :-)</p>
  
  <p>*not sure if possible bacause of the rasterizer and the pixel shader (if any), i mean, in the end it's all about pixels, right?</p>