k3d/share/shaders/k3d_luna.sl:59:  float raydist;
k3d/share/shaders/k3d_luna.sl:175:      raydist = 0.2 + 0.2 * snoise(20 * mod(u + 0.022, 1));
k3d/share/shaders/k3d_luna.sl:176:      lighten *= (1 - smoothstep(raydist - .2, raydist, pd));
