3D snoise has artifacts and periodic tendencies

Inizia eseguendo il PerlinNoiseGenJob fornito e ispezionando la texture generata da noise.snoise(float3(pnx, pny, z)) con le dimensioni e la frequenza mostrate. Segui l’implementazione di 3D snoise e i relativi test o esempi, quindi verifica che l’output generato non mostri più la periodicità diagonale segnalata né i pixel discontinui -1/1.

The provided 3D snoise function produces very low quality perlin noise and appears to be unusable for any practical application.

Here is a sample output of the algorithm, converted to PNG format:

As you can see, there is a diagonal periodic nature to it at higher scales. And, if you look very closely, you can see a pattern of discontinuous individual pixels (stuck at values -1 or 1).

Here is the code I used to generate this texture. Perhaps I made a mistake somewhere?

    [BurstCompile]
    public struct PerlinNoiseGenJob : IJob, IDisposable
    {
        public PerlinNoiseGenJob(int2 seed, float frequency, int2 origin, int2 dimensions, float valueMultiplier=1)
        {
            this.seed = seed;
            this.frequency = frequency;
            this.origin = origin;
            this.dimensions = dimensions;
            this.valueMultiplier = valueMultiplier;
            perlinNoise = new NativeArray<float>(dimensions.x * dimensions.y, Allocator.TempJob, NativeArrayOptions.UninitializedMemory);
        }
        
        public int2 seed;

        public float frequency;

        public int2 origin;

        public int2 dimensions;

        public float valueMultiplier;

        public NativeArray<float> perlinNoise;
        
        public void Execute()
        {
//            float z = (float) hash(seed) / uint.MaxValue;
            float z = 0;
            for (int i = 0; i < perlinNoise.Length; i++)
            {
                int ox = i % dimensions.x;
                int oy = i / dimensions.x;
                float pnx = (origin.x + ox) * frequency;
                float pny = (origin.y + oy) * frequency;
                perlinNoise[i] = noise.snoise(float3(pnx, pny, z)) * valueMultiplier;
            }
        }

        public void Dispose()
        {
            perlinNoise.Dispose();
        }
    }

    public class PerlinNoiseTextureGenerator : MonoBehaviour
    {
        public Texture2D texture;
        
        private void Start()
        {
            var dimensions = int2(1000,1000);
            var job = new PerlinNoiseGenJob(int2(5,12), 1f/10, int2(0,0), dimensions);
            var startTime = Time.realtimeSinceStartup;
            var handle = job.Schedule();
            handle.Complete();
            Debug.Log("Run time: "+(Time.realtimeSinceStartup - startTime));
            
            Color[] colors = new Color[dimensions.y * dimensions.x];
            for (int i=0; i<job.perlinNoise.Length; i++)
            {
                colors[i] = new Color((job.perlinNoise[i]+1)/2, 0,0);
            }
            
            texture = new Texture2D(dimensions.x,dimensions.y);
            texture.SetPixels(colors);
            
            //AssetDatabase.CreateAsset(texture, "Assets/Generated/Perlin.asset");
            File.WriteAllBytes("D:\\Perlin2.png", texture.EncodeToPNG());
            
            job.Dispose();
        }
    }