gistfile1.txt

surface
ambocc(float samples = 128)
{
        float occ = 0;

        normal nf = faceforward(normalize(N), I);

        gather("illuminance", P, nf, PI/2, samples, "distribution", "cosine") {
                    occ += 1;
        }

        float ave = occ / samples;

        Ci = (1 - ave) * Cs;
        Oi = 1;
}