鼠标坐标转换成世界坐标

using UnityEngine;
using System.Collections;

public class shubiao : MonoBehaviour {
	
	RaycastHit hitt = new RaycastHit();
	// Use this for initialization
	void Start () {
	

	}
	
	// Update is called once per frame
	void Update () {
	Ray ray = camera.ScreenPointToRay(Input.mousePosition);
	Physics.Raycast(ray,out hitt);
	Debug.Log(hitt.point.x);
	}
		
}