title: Drawing a mobius strip in OpenGL
body: <p>I'm trying to draw a Mobius strip using parametric equation such that it is always 'lit' (i.e. all of the normal vectors point towards the camera).</p>
  
  <p>The main problem that I have is that the mobius strip is not orientable, so however I orient the strip, some normal vectors are going to point away from the camera.  Is there a smart way to determine when to "flip" the normal vector such that it always points towards the camera?</p>
  
  <p>I've tried drawing the mobius strip twice such that normals are in both direction, but I then I get black and white strips from z-fighting.</p>