Group tool for Unity3D

GroupUtility.cs

//	Group Utility
//  groups objects, registers Undo, and sets pivot as an average of children
//	Made by Ryan Miller (https://www.ryanmiller.ca)

using UnityEngine;
using System.Collections;
using UnityEditor;
using System;

[ExecuteInEditMode]
public class GroupUtility : Editor {
	[MenuItem("Edit/Group %g", false)]
	public static void Group() {
		if (Selection.transforms.Length > 0) {
			GameObject group = new GameObject("Group");

			// set pivot to average of selection
			Vector3 pivotPosition = Vector3.zero;
			foreach (Transform g in Selection.transforms) {
				pivotPosition += g.transform.position;
			}
			pivotPosition /= Selection.transforms.Length;
			group.transform.position = pivotPosition;

			// register undo as we parent objects into the group
			Undo.RegisterCreatedObjectUndo(group, "Group");
			foreach (GameObject s in Selection.gameObjects) {
				Undo.SetTransformParent(s.transform, group.transform, "Group");
			}

			Selection.activeGameObject = group;
		}
		else {
			Debug.LogWarning("You must select one or more objects.");
		}
	}
}