k3d/share/shaders/k3d_stones.sl:110: float surface_mag = 0;
k3d/share/shaders/k3d_stones.sl:152:    surface_mag = max(surface_mag,mag);
k3d/share/shaders/k3d_stones.sl:171:        surface_mag += grunge * grunginess;
k3d/share/shaders/k3d_stones.sl:177:  P += Km * surface_mag * normalize(N);
k3d/share/shaders/k3d_stones.sl:181:  N = normalize(calculatenormal(P + Km * surface_mag * normalize(N)));
