unity

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Tilemaps;

public class LevelManager : MonoBehaviour {


    private Tile[] tiles;
    private Tilemap[] layers;
    private GameObject map;
    private GameObject player;
    private GridLayout gridLayout;

    void LoadTiles(string name)
    {
        tiles = Resources.LoadAll<Tile>("Tilesets/" + name);
    }

    void GenerateRoom()
    {
        for (int x = 0; x < 20; x++)
        {
            for (int y = 0; y < 8; y++)
            {
                layers[0].SetTile(new Vector3Int(x, y, 0), tiles[1]);
            }
        }

        for (int x = 1; x < 19; x++)
        {
            for (int y = 1; y < 7; y++)
            {
                layers[0].SetTile(new Vector3Int(x, y, 0), tiles[0]);
            }
        }
    }

    void AddPlayer()
    {
        player = Resources.Load<GameObject>("Prefabs/player");
        Instantiate(player);
        player.transform.position = gridLayout.CellToWorld(new Vector3Int(3,3,0));
    }


    // Use this for initialization
    void Start() {

        map = GameObject.Find("Map");
        gridLayout = map.GetComponent<Grid>();
        layers = new Tilemap[3];

        for (int i = 0; i < layers.Length; i++)
        {
            layers[i] = map.transform.GetChild(i).GetComponent<Tilemap>();
        }

        LoadTiles("Cave");
        GenerateRoom();
        AddPlayer();
    }

}