一、创建一个空GameObject和脚本GizmosTest.cs

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]//让脚本在编辑模式下运行
public class GizmosTest : MonoBehaviour {

    Transform mTran;

    void Start()
    {
        mTran = transform;
    }

    void OnDrawGizmos()
    {
        Gizmos.color = Color.yellow;
        Gizmos.DrawWireCube(mTran.position, new Vector3(1, 1, 1));
	}
}

Scene窗口中的效果