Tilemap2017 Access position & sprite of specific Tile in new Grid System 2dGame

Instead of Vector3, use a custom class that is similar but doesn't involve expensive and postentially inaccurate floating point operations. I wrote one that uses integers instead of floating point numbers:

 using UnityEngine;
 using System.Collections;
 using System;
 
 [System.Serializable]
 public struct Coordinate3 : IEquatable<Coordinate3> {
     public int x;
     public int y;
     public int z;
 
     
     public Coordinate3() {
         x = 0;
         y = 0;
         z = 0;
     }
     
 
     public Coordinate3(int a, int b, int c) {
         x = a;
         y = b;
         z = c;
     }
 
     public Coordinate3(Vector3 v3) {
         x = Mathf.RoundToInt(v3.x);
         y = Mathf.RoundToInt(v3.y);
         z = Mathf.RoundToInt(v3.z);
     }
 
     public bool Equals(Coordinate3 other) {
 
         if (this.x == other.x && this.y == other.y && this.z == other.z) {
             return true;
         }
         else {
             return false;
         }
     }
 
     public override int GetHashCode() {
         return x.GetHashCode() ^ y.GetHashCode() ^ z.GetHashCode();
     }
 
 }
 
 

Your dictionary would looke like this, assuming that you have a class called Tile:

 public Dictionary<Coordinate3,Tile> tiles = new Dictionary<Coordinate3,Tile>();
 
 tiles.Add(new Coordinate3(2,65,7), new Tile());