title: Stage 3D - draw orbit lines 'mathematically'
body: <p>I'd like to know if there's a way, using Stage3D and AGAL, to draw just the perimeter of a circle without using an actual mesh; I’m thinking the vertex shader could, somehow, be ‘tricked’ into thinking it’s processing the vertices of a mesh, while always setting the op (output position) register to the same distance from a point in space on a specific plane. (I'd like to render the orbits of planets in a space game I'm making)<br>
  I can't get my head around how that might be done though. Any ideas?</p>