Unity Script Reference – ExecuteInEditMode

ExecuteInEditMode Inherits from Attribute

Makes a script execute in edit mode.

By default scripts are only executed in playmode. By adding this attribute, each script instance will always have its Update, FixedUpdate, and OnGUI functions executed every frame while the Editor is running.

JavaScripts

// Make the script also execute in edit mode.
@script ExecuteInEditMode()

// Just a simple script that looks at the target transform.
var target : Transform;
function Update () {
if (target)
transform.LookAt(target);
}

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
public class example : MonoBehaviour {
public Transform target;
void Update() {
if (target)
transform.LookAt(target);

}
}

import UnityEngine
import System.Collections

[ExecuteInEditMode]
class example(MonoBehaviour):

public target as Transform

def Update():
if target:
transform.LookAt(target)