How to have graphic continuity in my chuncks ?(2d procedural / sprites)

I'm trying to learn how to procedurally create a world in 2d. After some research i did this :

I create a DataWorld.cs a DataChunk.cs and a DataSprite.cs to store all the data and separate Data from graphic creation. And i create an other script WorldGenerator.cs to actually create the world.

it looks like this :

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class WorldGenerator : MonoBehaviour {
 
     public Sprite[] sprites;
     public SpriteRenderer sp;
     public int chunk_size_x;
     public int chunk_size_y;
     public int world_size_x;
     public int world_size_y;    
   
     int _chunkNum = -1;
     int _scale;
     int _magnitude;
     float _power = 1;
     int _treshold = 15;
     GameObject _chunkGO;
 
     SpriteRenderer spriteClone;
 
     void Start () 
     {    
         sprites = Resources.LoadAll<Sprite>("spriteTest");
         _scale = (int)Random.Range(10f,50f);
         _magnitude =(int) Random.Range((float)_scale-10, _scale+20);

         MakeWorld(world_size_x, world_size_y, chunk_size_x, chunk_size_y);
     }
 
     public void MakeWorld(int world_size_x, int world_size_y, int chunk_size_x, int chunk_size_y)
     {
     
         DataWorld world = new DataWorld(world_size_x, world_size_y, chunk_size_x, chunk_size_y);
 
         for(int x = 0; x < world_size_x; x++)
         {
             for(int y = 0; y < world_size_y; y++)
             {
                 MakeChunk(world, chunk_size_x,chunk_size_y);
                 _chunkGO.transform.position = new Vector3 (world.chunks[x,y].posX, world.chunks[x,y].posY,0) ;    
 
             }
         }
     }
 
 
     public void MakeChunk(DataWorld world, int chunk_size_x, int chunk_size_y)
     {
         _chunkNum++;
         GameObject chunkGO = new GameObject();
         chunkGO.name = "CHUNK" + " " + _chunkNum;
         _chunkGO = chunkGO;
 
          for(int x=0; x< chunk_size_x; x++)
         {
             for(int y = 0; y< chunk_size_y; y++)
             {
 
                 if(y<PerlinNoise(x/8,0,_scale,_magnitude,_power)) 
                 {
 
                     spriteClone = (SpriteRenderer)Instantiate(sp, new Vector2(x,y), Quaternion.identity);
                     spriteClone.transform.parent = chunkGO.transform;
                     spriteClone.name = "sprite " +x + " , " +y;
                     world.GetAllChunks().spriteTile[x,y].spr = spriteClone;
                     world.GetAllChunks().spriteTile[x,y].type = DataSprite.TYPE.BLACK;
 
                 }
             }
 
         }
 
         for(int x=0; x< chunk_size_x; x++)
         {    
             for(int y = 0; y< chunk_size_y; y++)
             {
 
                     CheckSpritePos(world.GetAllChunks(),x,y);
                     UpdateSpritesGraphics(world.GetAllChunks(),world.GetAllChunks().spriteTile[x,y].spr,x,y);
 
 
             }
         }
     }
 int PerlinNoise(int x,int y, float scale, float mag, float power){
     
     float rValue;
     rValue=Noise.Noise.GetNoise (((double)x) / scale, ((double)y)/ scale,0);
     rValue*=mag;
     
     if(power!=0)
     {
         rValue=Mathf.Pow( rValue, power);
     }
     
     return (int) rValue;
 }

But the way i do it all instantiates chunks are the same. I understand why there are all the same, but i can't figure out how to make them continue each other base on the PerlinNoise function.

EDIT :

So i fixed the continuity on the axis X by adding

  if(y<PerlinNois((x+chunk.posX),0,50,100,1f))

It works fine when i only have one dimension in my world ( i only add chunk along the X axis). But when i have 2 dimension let say my world size is

• world_size_x =4

• world_size_y =2

I can't figure out how to add chunk.posY to sample the noise corectly.

 if(y<PerlinNoise((x+chunk.posX+chunk.posY),0,50,100,1f))

does not work. I did plenty of other test but none of them worked. Where and how do i have to add the chunk.posY ?

EDDIT 2

nevermind after several hour of break i finally had the right brain wave :

  if(y+chunk.posY<PerlinNoise((x+chunk.posX),0,50,100,1f))