Unity 2D Game Development, Map Composition using Tilemap System How to design and compose game levels using Tilemap.

Unity is a powerful engine for 2D game development, and among its features, the Tilemap system is an excellent tool that helps
simplify game level design. This article will detail how to design and structure game levels using Tilemap, starting with the
basics and exploring practical examples of its application.

1. What is Tilemap?

Tilemap is a pattern-based map composition system used in Unity for creating 2D games. It combines multiple small images called
’tiles’ to create maps, allowing developers to easily create complex terrains. This system is mainly utilized in various game genres
such as platform games, puzzle games, and RPGs. The advantages of Tilemap include:

  • Efficient resource management
  • Easy level design
  • Fast performance
  • Flexible modifications and reusability

2. Setting Up Tilemap

To use Tilemap, you must first start working in Unity. Follow the steps below to set up Tilemap:

  1. Create a Unity Project: Open Unity Hub and create a new 2D project.
  2. Import Tilemap Package: Install the 2D Tilemap Editor package from the Unity Package Manager.
  3. Create Tilemap: Right-click in the Hierarchy window, select 2D Object > Tilemap >
    Rectangular to create a new Tilemap.
  4. Create Grid: Select the Tilemap and configure it to fit the Grid. The Grid will serve as the
    basic structure for the Tilemap.

3. Creating Tiles

To create tiles for use in the Tilemap, prepare Sprites. Each tile will have a unique Sprite. Let’s create tiles following the steps
below:

  1. Import Sprites: Drag and drop the tile images you wish to use into the Games, Assets folder.
  2. Create Tile Asset: Select the tile in the Project window, right-click, and click Create >
    Tile to create a Tile Asset. Drag and drop the image onto the created Tile Asset.
  3. Create Tile Palette: Select Window > 2D > Tile Palette. Create a new palette and add the tiles you just created to it.

4. Placing Tiles on Tilemap

Once everything is set up, you can place tiles on the Tilemap using the Tile Palette. Simply select a tile from the Tile Palette
and drag and drop it onto the Tilemap. With this, you can perform the following tasks:

  • Adjust the size and shape of tiles to create various maps.
  • Create continuous tile placements to connect terrains naturally.
  • Construct complex structures from combinations of tiles.

5. Utilizing the Features of Tilemap

To use the Tilemap system more efficiently, you can leverage certain features. For instance, you can use the Tilemap Collider and
Tilemap Renderer. The Tilemap Collider implements the necessary physical properties for when the player collides with tiles. The
Tilemap Renderer is responsible for the visual representation of tiles and allows for individual adjustments of each tile’s level.

Below is a C# code snippet demonstrating how to add a Collider to the Tilemap: 

        
        using UnityEngine;
        using UnityEngine.Tilemaps;

        public class TilemapSetup : MonoBehaviour
        {
            private Tilemap tilemap;

            void Start()
            {
                tilemap = GetComponent<Tilemap>();
                tilemap.GetComponent<TilemapCollider2D>().usedByEffector = true;
            }
        }

6. Upgrading Levels with Tilemap

You can upgrade game levels using Tilemap. This step will add complexity and various elements to the level. Below is an example
showing a simple level upgrade process. 

        
        public class LevelManager : MonoBehaviour
        {
            public Tilemap tilemap;
            public GameObject playerPrefab;
            private GameObject player;

            void Start()
            {
                player = Instantiate(playerPrefab, new Vector3(0, 0, 0), Quaternion.identity);
            }

            public void UpdateLevel()
            {
                // Change the level based on specific tiles
                TileBase currentTile = tilemap.GetTile(tilemap.WorldToCell(player.transform.position));
                if (currentTile != null)
                {
                    if (currentTile.name == "BonusTile")
                    {
                        // Action when placed on bonus tile
                        Debug.Log("Bonus Tile Activated!");
                    }
                }
            }
        }

7. Performance Optimization

Using Tilemap allows for more efficient performance management, but here are a few optimization tips:

  • Remove unnecessary tiles and activate only the needed ones.
  • Use Static Batching to improve the performance of static game objects.
  • Adjust the rendering layer of the Tilemap to focus only on visible tiles.

8. Limitations of Tilemap and Overcoming Them

While Tilemap is powerful, it does have some limitations. For example, it may be restrictive for complex terrains. However, this
issue can be resolved by combining it with prefabs. By utilizing prefabs in certain areas, you can create a wider variety of objects
and add depth to your game.

9. Utilizing Tilemap and the Asset Store

The Unity Asset Store offers many Tilemap-related assets and tools that can enhance the operation and design of your game. For
instance, you can purchase assets that provide unique tile animations or patterns to incorporate into your game.

10. Conclusion

This article explored how to effectively design and structure levels in 2D games using Unity’s Tilemap system. Tilemap provides
developers with significant convenience and efficiency. Challenge yourself with deeper game designs through various use cases.
Actively utilize the diverse features and characteristics of Tilemap for improving the quality of your game.