unity 3d中简单巧妙的实现拖动鼠标旋转物体

using UnityEngine;
using System.Collections;

public class BaseRotate : MonoBehaviour {

public Vector3 mousePos;

IEnumerator OnMouseDown()
{

mousePos = Input.mousePosition;

while (Input.GetMouseButton(0))
{
Vector3 offset = mousePos - Input.mousePosition;

transform.Rotate(Vector3.up * offset.x, Space.World);
transform.Rotate(Vector3.right*offset.y,Space.World);

mousePos=Input.mousePosition;
yield return null;
}
}
}