k3d/share/shaders/k3d_windowlight.sl:43:  uniform vector path;
k3d/share/shaders/k3d_windowlight.sl:48:  path = normalize(from - to);
k3d/share/shaders/k3d_windowlight.sl:56:  PL = Ps - path * (d / (path.inv));
k3d/share/shaders/k3d_windowlight.sl:58:  illuminate(PL, -path, .01)
