LibNoise.FastBillow.GetValue C# (CSharp) Method

        public double GetValue(double x, double y, double z)
        {
            double value = 0.0;
            double signal = 0.0;
            double curPersistence = 1.0;
            long seed;

            x *= Frequency;
            y *= Frequency;
            z *= Frequency;

            for (int currentOctave = 0; currentOctave < OctaveCount; currentOctave++)
            {

                seed = (Seed + currentOctave) & 0xffffffff;
                signal = GradientCoherentNoise(x, y, z, (int)seed, NoiseQuality);
                signal = 2.0 * System.Math.Abs(signal) - 1.0;
                value += signal * curPersistence;

                x *= Lacunarity;
                y *= Lacunarity;
                z *= Lacunarity;
                curPersistence *= Persistence;
            }

            value += 0.5;

            return value;
        }