k3d/share/shaders/k3d_antialiasedchecks.sl:35:  float Nfactor;        /* Multiplicative factor for AA due to normal */
k3d/share/shaders/k3d_antialiasedchecks.sl:45:  Nfactor = abs (Nf . I) / (length(Nf) * length(I));
k3d/share/shaders/k3d_antialiasedchecks.sl:46:  sfuzz = .5 * swidth * frequency / Nfactor;
k3d/share/shaders/k3d_antialiasedchecks.sl:47:  tfuzz = .5 * twidth * frequency / Nfactor;
k3d/share/shaders/k3d_brick3.sl:60:  float Nfactor;
