Thank you for asking and no, my interests changed since then. Just to clarify the background of this particular topic: The strak/surfacing (ICEMsurf or former VSR Tools for Rhino) community is using zebra lights for live analyzing of surfaces in a different way than in Rhino possible. The stripes are fixed to the object, even if you change the view. The stripes only change if you drag a CV or otherwise change the geometry. Mathematically, these are Isophotes of a light source which is bound to the object and not to the position of the view. May be that helps. I don’t want to mess up your original topic with that stuff. Here another related topic: Draft Angle Analysis Component