title: Drawing Curves on Surfaces in WebGL
body: <p>Well, the title pretty much states it.  I want to be able to draw a curve on a surface in Web GL.  So for example, I'd like to draw a parabola on the surface of a sphere.</p>
  
  <p>x = cos(theta)sin(phi); y = sin(theta)sin(phi); z = cos(phi).  </p>
  
  <p>If you make theta = theta(t) and phi = phi(t), you can draw curves on the surface.</p>
  
  <p>I guess lines on shapes is what I need.  Anyone know if that's possible in Web GL?</p>