Camera Colliding with Terrain

Hello, I want to make my camera in my racing game collide with the terrain so it cant go through the terrain at all. This is the code I added to my script in order to try and achieve the behaviour I'm looking for:

 using UnityEngine;
 using System.Collections;

 public class SmoothFollow : MonoBehaviour 
 {
     private Ray ray;
     private RaycastHit hit;
     public GameObject player;
     public Transform target;

     void Start()
     {
         ray = new Ray(target.position, target.position - transform.position);
     }

     void Update()
     {
         if (Physics.Raycast(ray, out hit))
         {
              transform.position = ray.GetPoint(hit.distance - 1);
         }
 
         if(cameraNum == -1)
         {
              cameraDistance = Vector3.Distance(target.position, target.position) + 140;
         }
         // Gets the sled position and adds the camera height to it.
         newHeight.y = target.transform.position.y + cameraHeight;
     
         if(Input.GetKeyUp(KeyCode.C) && allowCameraChange)
         {
             ChangeCameraView();        
         } 
     }
 }

Its not giving me any errors its just not doing anything at all besides the normal camera stuff I have going on in the script. Any help or insight would be awesome.

Thanks, Hans