Destructible terrain systems allow players to modify the environment during gameplay. Instead of static levels, the world becomes interactive and reactive.

Players can dig, explode terrain, create craters, or destroy parts of the environment. This technique is used in many modern games to increase immersion.

Games like Minecraft, Teardown, Deep Rock Galactic, and No Man’s Sky use destructible terrain systems to create dynamic gameplay experiences.

Two Main Approaches to Destructible Terrain

There are two common ways to implement destructible terrain in Unity:

• Mesh Deformation – modifying terrain vertices
• Voxel Terrain – modifying a 3D grid of blocks

Each method has different advantages depending on the type of game you are building.

Method 1: Mesh-Based Terrain Deformation

In this approach, the terrain is represented by a mesh. When an explosion occurs, nearby vertices are moved to create a crater.

First we access the terrain mesh.

Mesh mesh;
Vector3[] vertices;

void Start()
{
    mesh = GetComponent<MeshFilter>().mesh;
    vertices = mesh.vertices;
}

Now we can modify vertices when an explosion happens.

public void CreateCrater(Vector3 explosionPoint, float radius, float depth)
{
    for(int i = 0; i < vertices.Length; i++)
    {
        Vector3 worldVertex = transform.TransformPoint(vertices[i]);
        float distance = Vector3.Distance(worldVertex, explosionPoint);

        if(distance < radius)
        {
            float falloff = 1 - (distance / radius);
            vertices[i].y -= depth * falloff;
        }
    }

    mesh.vertices = vertices;
    mesh.RecalculateNormals();
}

This creates a crater effect by pushing terrain vertices downward.

Method 2: Voxel-Based Terrain

Voxel terrain represents the world as a 3D grid of blocks.

Each voxel can be either solid or empty.

int[,,] voxels = new int[100,100,100];

To destroy terrain, we remove voxels in a radius.

void DestroyTerrain(Vector3 position, float radius)
{
    for(int x = 0; x < sizeX; x++)
    {
        for(int y = 0; y < sizeY; y++)
        {
            for(int z = 0; z < sizeZ; z++)
            {
                Vector3 voxelPos = new Vector3(x,y,z);

                if(Vector3.Distance(voxelPos, position) < radius)
                {
                    voxels[x,y,z] = 0;
                }
            }
        }
    }
}

After modifying voxels, the mesh must be regenerated.

Generating the Terrain Mesh

Voxel terrain is usually converted to a mesh using algorithms such as:

• Marching Cubes
• Dual Contouring
• Greedy Meshing

Greedy meshing is commonly used in voxel games because it reduces the number of triangles.

Explosion Example

Here is a simple explosion that modifies the terrain.

void Explode(Vector3 position)
{
    float radius = 5f;

    DestroyTerrain(position, radius);
    GenerateMesh();
}

This removes terrain in a spherical area.

Performance Optimization

Destructible terrain systems can be expensive if not optimized.

• Use chunk-based terrain
• Update only affected chunks
• Use mesh pooling
• Use Unity Jobs + Burst
• Reduce mesh resolution

Chunk-Based Terrain System

Large destructible worlds are usually divided into chunks.

Instead of regenerating the entire terrain, only the affected chunk is updated.

Dictionary<Vector2Int, TerrainChunk> chunks;

This dramatically improves performance.

Gameplay Uses

• Digging systems
• Explosion craters
• Mining resources
• Dynamic level design
• Physics-based destruction

Games Using Destructible Terrain

• Minecraft
• Deep Rock Galactic
• Teardown
• Red Faction

These games rely heavily on destructible environments to create unique gameplay experiences.

Final Thoughts

Destructible terrain systems can transform static environments into interactive worlds.

Whether using mesh deformation or voxel terrain, the key idea is the same: allow players to shape the world around them.

With proper optimization and chunk systems, destructible terrain can scale to massive worlds.