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Unity Engine

Build a structure with prefabs

Use prefabs to instantiate several copies of a block prefab to construct a wall.
Read time 2 minutesLast updated 18 days ago
You can use code to procedurally generate copies of a prefab in a particular configuration. The following example creates a wall of block prefab instances.

Create a block prefab asset

To create a wall of blocks, you must first have a block prefab asset to create the wall with.
  1. In the Hierarchy, right-click and select
    3D Object

    ?

    > Cube.
  2. Drag the cube into the Assets folder in the Project window. Unity creates a prefab asset of the cube.
  3. Rename the prefab asset to 
    Block
    .
  4. Delete the original cube asset from the Hierarchy.

Create a script that instantiates blocks

Create a MonoBehaviour script and name it 
Wall
. Add the following code into the 
Wall
script:
using UnityEngine;public class Wall : MonoBehaviour{   public GameObject block;   public int width = 10;   public int height = 4;     void Start()   {       for (int y=0; y<height; ++y)       {           for (int x=0; x<width; ++x)           {               Vector3 pos = transform.position + new Vector3(x, y, 0);               Instantiate(block, pos, Quaternion.identity);           }       }          }}

Attach the script to an empty GameObject

  1. Create an empty GameObject. Right-click on the Hierarchy and select Create Empty.
  2. Attach the 
    Wall
    script to the empty GameObject.
  3. Drag the 
    Block
    prefab asset into the Block field,
  4. Enter Play mode and Unity generates a wall with the 
    Block
    prefab.

A wall built from 4 rows of 10 blocks. The empty GameObject is selected in the Inspector, with the Block prefab asset assigned to the Block field.

You can also use code to place prefabs in a grid or other configurations. The following example places the cubes in a circular formation:
using UnityEngine;public class CircleFormation : MonoBehaviour{    // Instantiates prefabs in a circle formation    public GameObject prefab;    public int numberOfObjects = 20;    public float radius = 5f;    void Start()     {        for (int i = 0; i < numberOfObjects; i++)        {            float angle = i * Mathf.PI * 2 / numberOfObjects;            float x = Mathf.Cos(angle) * radius;            float z = Mathf.Sin(angle) * radius;            Vector3 pos = transform.position + new Vector3(x, 0, z);            float angleDegrees = -angle*Mathf.Rad2Deg;            Quaternion rot = Quaternion.Euler(0, angleDegrees, 0);            Instantiate(prefab, pos, rot);        }    }}
When you attach the script to an empty GameObject and enter Play mode, Unity generates the cubes in the following formation:

A circular arrangement of blocks.

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