Perlin噪声梯度生成问题

Question

我看到的渐变似乎是一个问题。我不确定该如何处理，但是渐变是在4x4网格中，并且它们与它的相邻渐变（生成错误的方向？）不匹配。我已经尝试过并试图寻找答案，但只能在Stackoverflow上找到与我的问题类似的其他帖子。这是我正在使用的代码：

using UnityEngine;
using System;
using System.Collections;

public class Noise : MonoBehaviour {

private const int GradientSizeTable = 256;
private System.Random random;
private readonly double[] _gradients = new double[GradientSizeTable * 3];
private readonly int[] perm = new int[] {
    225,155,210,108,175,199,221,144,203,116, 70,213, 69,158, 33,252,
    5, 82,173,133,222,139,174, 27,  9, 71, 90,246, 75,130, 91,191,
    169,138,  2,151,194,235, 81,  7, 25,113,228,159,205,253,134,142,
    248, 65,224,217, 22,121,229, 63, 89,103, 96,104,156, 17,201,129,
    36,  8,165,110,237,117,231, 56,132,211,152, 20,181,111,239,218,
    170,163, 51,172,157, 47, 80,212,176,250, 87, 49, 99,242,136,189,
    162,115, 44, 43,124, 94,150, 16,141,247, 32, 10,198,223,255, 72,
    53,131, 84, 57,220,197, 58, 50,208, 11,241, 28,  3,192, 62,202,
    18,215,153, 24, 76, 41, 15,179, 39, 46, 55,  6,128,167, 23,188,
    106, 34,187,140,164, 73,112,182,244,195,227, 13, 35, 77,196,185,
    26,200,226,119, 31,123,168,125,249, 68,183,230,177,135,160,180,
    12,  1,243,148,102,166, 38,238,251, 37,240,126, 64, 74,161, 40,
    184,149,171,178,101, 66, 29, 59,146, 61,254,107, 42, 86,154,  4,
    236,232,120, 21,233,209, 45, 98,193,114, 78, 19,206, 14,118,127,
    48, 79,147, 85, 30,207,219, 54, 88,234,190,122, 95, 67,143,109,
    137,214,145, 93, 92,100,245,  0,216,186, 60, 83,105, 97,204, 52};

public void pNoiseSeed(int s)
{
    seed = s;
}
private int seed;

public double pNoise(double x, double y, double z)
{
    random = new System.Random(seed);
    InitGradients();

    int ix = (int)Math.Floor(x);
    double fx0 = x - ix;
    double fx1 = fx0 - 1;
    double wx = Smooth(fx0);

    int iy = (int)Math.Floor(y);
    double fy0 = y - iy;
    double fy1 = fy0 - 1;
    double wy = Smooth(fy0);

    int iz = (int)Math.Floor(z);
    double fz0 = z - iz;
    double fz1 = fz0 - 1;
    double wz = Smooth(fz0);

    double vx0 = Lattice(ix, iy, iz, fx0, fy0, fz0);
    double vx1 = Lattice(ix + 1, iy + 1, iz + 1, fx1 + 1, fy0 + 1, fz0 + 1);
    double vy0 = Lerp(wx, vx0, vx1);

    vx0 = Lattice(ix, iy + 1, iz, fx0, fy1, fz0);
    vx1 = Lattice(ix + 1, iy + 1, iz, fx1, fy1, fz0);
    double vy1 = Lerp(wx, vx0, vx1);

    double vz0 = Lerp(wy, vy0, vy1);

    vx0 = Lattice(ix, iy, iz + 1, fx0, fy0, fz1);
    vx1 = Lattice(ix + 1, iy, iz + 1, fx1, fy0, fz1);
    vy0 = Lerp(wx, vx0, vx1);

    vx0 = Lattice(ix, iy + 1, iz + 1, fx0, fy1, fz1);
    vx1 = Lattice(ix + 1, iy + 1, iz + 1, fx1, fy1, fz1);
    vy1 = Lerp(wx, vx0, vx1);

    double vz1 = Lerp(wy, vy0, vy1);
    return Lerp(wz, vz0, vz1);
}

private void InitGradients()
{
    for (int i = 0; i < GradientSizeTable; i++)
    {
        double z = 1f - 2f * random.NextDouble();
        double r = Math.Sqrt(1f - z * z);
        double theta = 2 * Math.PI * random.NextDouble();
        _gradients[i * 3] = r * Math.Cos(theta);
        _gradients[i * 3 + 1] = r * Math.Sin(theta);
        _gradients[i * 3 + 2] = z;
    }
}

private int Permutate(int x)
{
    const int mask = GradientSizeTable - 1;
    return perm[x & mask];
}

private int Index(int ix, int iy, int iz)
{
    return Permutate(ix + Permutate(iy + Permutate(iz)));
}

private double Lattice(int ix, int iy, int iz, double fx, double fy, double fz)
{
    int index = Index(ix, iy, iz);
    int g = index*3;
    return _gradients[g] * fx + _gradients[g + 1] * fy + _gradients[g + 2] * fz;
}

private double Lerp(double t, double value0, double value1)
{
    return value0 + t * (value1 - value0);
}

private double Smooth(double x)
{
    return x * x * (3 - 2 * x);
}
}

任何帮助将不胜感激！ :)

这是一张图片：