how to make multi-touch for 3d models

I have got this script for gui texture but how would I change it to 3d models help please anyone here is the script

 using UnityEngine;
 using System.Collections;
  
 public class TouchLogic: MonoBehaviour {
 5. 
   void Update (){ // enclose the Update function in curly braces
     //is there a touch on screen
     if (Input.touches.Length <= 0) // <- no touches means <= 0, not < 0
     {
 10.      //if no touches then execute this code
     }
     else // <- there are no parenthesis after else!
     {
       //loop through all of the touches on the screen
 15.      for (int i=0; i < Input.touchCount; i++ )
       {
         //execute this code for current touch (i)on screen
         if(this.guiTexture.HitTest(Input.GetTouch (i).position ))
         {
 20.          //if current touch hits our guitexture, run this code
           if(Input.GetTouch (i).phase == TouchPhase.Began )
           {
             Debug.Log("the touch has begun on" +this.name);
           }
 25.          if(Input.GetTouch (i).phase == TouchPhase.Ended )
           {
             Debug.Log("the touch has ended on" +this.name);
           }
         }
 30.      }
     }
   }
 }