unity get perlin noise 3d
public static float PerlinNoise3D(float x, float y, float z)
{
float xy = Mathf.PerlinNoise(x, y);
float xz = Mathf.PerlinNoise(x, z);
float yz = Mathf.PerlinNoise(y, z);
float yx = Mathf.PerlinNoise(y, x);
float zx = Mathf.PerlinNoise(z, x);
float zy = Mathf.PerlinNoise(z, y);
return (xy + xz + yz + yx + zx + zy) / 6;
}