Unity - Get transparency of one pixel

gistfile1.txt

using UnityEngine;
 using System.Collections;
 
 public class RayCasting : MonoBehaviour {
         
     void Update () {
         
         if (!Input.GetMouseButtonDown(0))
         {
             return;
         }
         
         var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
         RaycastHit[] hits = Physics.RaycastAll(ray);
         
         Vector3 v;
         bool[] transparent = new bool[hits.Length];
         
         for (int i=0; i < hits.Length; i++)
         {
             Texture2D pic = hits[i].transform.gameObject.renderer.material.mainTexture as Texture2D;
             // - Translate the RaycastHit.point to local coordinates of the object
             v = hits[i].transform.worldToLocalMatrix.MultiplyPoint(hits[i].point);
             
             // - Translate the coordinates to a UV system (0 to 1) based on the object size.
             float xPic = 10 - (v.x + 5);
             float yPic = v.y + 5;
             
             // - Use Texture2D.GetPixel() or Texture2D.GetPixelBilinear()
             // - Examine the alpha value of the color returned
             if(pic.GetPixel((int)((xPic/10)*pic.width),(int)((yPic/10)*pic.height)).a).a < 0.5)
                 transparent[i] = true;    //pixel is transparent
                 Debug.Log(hits[i].transform);
         }
         
         int res = 0;
         if(hits.Length != 0)
             res = exam(hits, transparent);
         //if front checking function found something
         //we remove it
         if(res != hits.Length)
             Destroy(hits[res].transform.gameObject);
     }
     // function which check, what is on front
     int exam(RaycastHit[] hits, bool[] t)
     {
         float tmp = 100;
         int resRay = hits.Length;
         
         for(int i = 0; i < hits.Length; i++)
         {
             if((hits[i].transform.position.z < tmp) && !t[i])
             {
                 tmp = hits[i].transform.position.z;
                 resRay = i;
             }
         }
         return resRay;
     }
 }