Creating massive open worlds is a common goal in modern games. However, generating a huge terrain all at once can quickly destroy performance and memory usage.

The solution used by many games such as Minecraft, Valheim, and No Man’s Sky is a chunk-based infinite terrain system.

Instead of generating the entire world at once, the game dynamically generates terrain chunks around the player as they move.

What Is a Chunk System?

A chunk is a small section of terrain that can be generated, loaded, and unloaded independently.

For example:

• Each chunk = 50×50 meters
• The world loads chunks near the player
• Chunks far away are destroyed or disabled

This makes the world appear infinite while keeping performance under control.

Basic Chunk Architecture

An infinite terrain system usually contains three main components:

• Chunk Generator – builds mesh data
• Chunk Manager – loads/unloads chunks
• Biome System – determines terrain type

Chunk Data Structure

public class TerrainChunk
{
    public Vector2Int coordinate;
    public GameObject chunkObject;
    public MeshRenderer renderer;
    public MeshFilter meshFilter;

    public TerrainChunk(Vector2Int coord, Transform parent)
    {
        coordinate = coord;

        chunkObject = new GameObject("Chunk_" + coord);
        meshFilter = chunkObject.AddComponent<MeshFilter>();
        renderer = chunkObject.AddComponent<MeshRenderer>();

        chunkObject.transform.parent = parent;
    }
}

Tracking Player Position

The chunk manager constantly checks which chunk the player is currently in.

Vector2Int GetPlayerChunk(Vector3 playerPos, int chunkSize)
{
    int x = Mathf.FloorToInt(playerPos.x / chunkSize);
    int z = Mathf.FloorToInt(playerPos.z / chunkSize);

    return new Vector2Int(x, z);
}

When the player moves into a new chunk, the system loads surrounding chunks.

Loading Chunks Around the Player

We generate chunks within a visible radius.

void LoadChunks(Vector2Int playerChunk)
{
    for(int y = -viewDistance; y <= viewDistance; y++)
    {
        for(int x = -viewDistance; x <= viewDistance; x++)
        {
            Vector2Int coord = new Vector2Int(
                playerChunk.x + x,
                playerChunk.y + y
            );

            if(!chunks.ContainsKey(coord))
            {
                CreateChunk(coord);
            }
        }
    }
}

Generating Chunk Terrain

Each chunk generates its terrain mesh using Perlin Noise.

float GetHeight(float worldX, float worldZ)
{
    float noise = Mathf.PerlinNoise(worldX * 0.01f, worldZ * 0.01f);
    return noise * heightMultiplier;
}

Because we use world coordinates instead of local chunk coordinates, terrain transitions remain seamless.

Adding Biomes to Infinite Terrain

Biome selection can be calculated using additional noise maps.

float temperature = Mathf.PerlinNoise(x * 0.003f, z * 0.003f);
float moisture = Mathf.PerlinNoise(x * 0.004f, z * 0.004f);

These values determine which biome appears in that region.

Example biome rules:

• Low temperature → Snow biome
• High temperature + low moisture → Desert
• Medium temperature + high moisture → Forest

Biome Height Differences

float ApplyBiomeHeight(float baseHeight, string biome)
{
    switch(biome)
    {
        case "Snow":
            return baseHeight * 1.8f;

        case "Forest":
            return baseHeight * 1.2f;

        case "Desert":
            return baseHeight * 0.4f;

        default:
            return baseHeight;
    }
}

This creates mountains in snowy areas and flatter terrain in deserts.

Unloading Distant Chunks

To keep memory usage low, chunks far away from the player should be removed.

if(distanceFromPlayer > maxViewDistance)
{
    Destroy(chunk.chunkObject);
}

This keeps only nearby terrain active.

Performance Improvements

• Use object pooling for chunks
• Generate terrain asynchronously
• Use Unity Jobs + Burst for large worlds
• Use LOD meshes for distant chunks

Real Games Using Chunk Systems

• Minecraft
• No Man’s Sky
• Valheim
• Astroneer

These games generate huge worlds by loading terrain chunks around the player.

Final Thoughts

Chunk-based procedural terrain is the foundation of infinite worlds in modern games.

By combining chunk generation, noise-based terrain, and biome systems, you can create massive environments that feel natural and endless.

With the right optimization techniques, even extremely large worlds can run smoothly in Unity.