u3d目标与摄像机之间的遮挡物变为透明

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class XrayCameral : MonoBehaviour {

public Transform tar;
public List<Renderer> listLastRend = new List<Renderer>();
// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update () {

for (int i = 0; i < listLastRend.Count; i++)
{
TransparencySet(listLastRend[i], 1.0f);
}
Vector3 tarDir = (tar.position - transform.position).normalized;
Debug.DrawLine(tar.position, transform.position, Color.red);

float tarDis = Vector3.Distance(tar.position, transform.position);
RaycastHit[] listHitObj = Physics.RaycastAll(transform.position, tarDir, tarDis);
Debug.Log(listHitObj.Length);
for (int i = 0; i < listHitObj.Length; i++)
{
RaycastHit hit = listHitObj[i];
if (hit.transform == tar.transform)
{
continue;
}
Renderer renderer = hit.collider.GetComponent<Renderer>();
listLastRend.Clear();

if (renderer)
{
listLastRend.Add(renderer);
TransparencySet(renderer,0.3f);
}
}

}

void TransparencySet(Renderer renderer,float a)
{
renderer.material.shader = Shader.Find("Transparent/Diffuse");
renderer.material.color = new Color(renderer.material.color.r, renderer.material.color.g, renderer.material.color.b, a);
}
}