title: Using the geometry shader for instancing
body: <p>So I want to draw lots of quads (or even cubes), and stumbled across this lovely thing called the geometry shader.</p>
  
  <p>I kinda get how it works now, and I could probably manipulte it into drawing a cube for every vertex in the vertex buffer, but I'm not sure if it's the right way to do it. The geometry shader happens between the vertex shader and the fragment shader, so it works on the vertices in <strong>screen space</strong>. But I need them in world space to do transformations.</p>
  
  <p>So, is it OK to have my vertex shader simply pipe the inputs to the geometry shader, and have the geometry shader multiply by the modelviewproj matrix after creating the primitives? It should be no problem with the unified shader architecture, but I still feel queasy when making the vertex shader redundant.</p>
  
  <p>Are there alternatives? Or is this really the 'right' way to do it?</p>