title: Circle clip and projection with D3 orthographic
body: <p>I'm working on <a href="http://bl.ocks.org/tomstove/5243213">this</a> and I'm having trouble with clipping the red circle elements as they appear on the globe even past the 90˚ clip angle. Also, is there a way you can apply the projection to the red circles, as in so it looks like they're on the surface of the globe relative to the orthographic angle? At the moment they just appear as 2d circles relative to the screen.</p>