Hi Nerds,
Here is the tutorial for creating a third person camera with dynamic wall collisions in Unity.
Demo: https://youtu.be/DPTWLs-zndI
Doc: https://1drv.ms/p/s!AvAlkrGEujhegijtt9rN5vqZys_u
Project: https://drive.google.com/open?id=0B9oh03OBnU50Ynh2ak1Rd2Z0Umc

Code Example:

using UnityEngine;
using System.Collections;

public class PlayerCamera : MonoBehaviour {

    public Transform targetTransform;

    private Camera _Cam;
    public Camera Cam{
        get{
            if(_Cam == null){
                _Cam = GetComponent<Camera>();
            }
            return _Cam;
        }
    }

    public bool isMoving;

    public Vector3 CamOffset = Vector3.zero;
    public Vector3 ZoomOffset = Vector3.zero;

    public float senstivityX = 5;
    public float senstivityY = 1;

    public float minY = 30;
    public float maxY = 50;

    public bool isZooming;

    private float currentX = 0;
    private float currentY = 1;


    void Update(){
        currentX += Input.GetAxis("Mouse X");
        currentY -= Input.GetAxis("Mouse Y");

        currentX = Mathf.Repeat(currentX, 360);
        currentY = Mathf.Clamp(currentY, minY, maxY);

        isMoving = (Input.GetAxis("Horizontal") != 0 || Input.GetAxis("Vertical") != 0) ? true: false;
        isZooming = Input.GetMouseButton(1);


        if(isMoving || isZooming){
            UpdatePlayerRotation();
        }


    }


    void UpdatePlayerRotation(){
        targetTransform.rotation = Quaternion.Euler (0, currentX, 0);

    }

    void LateUpdate(){

        Vector3 dist = isZooming? ZoomOffset : CamOffset;

        Quaternion rotation = Quaternion.Euler(currentY, currentX, 0);
        transform.position = targetTransform.position + rotation * dist;

        transform.LookAt(targetTransform.position);


        CheckWall();
    }


    public LayerMask wallLayer;

    void CheckWall()
    {

        RaycastHit hit;


        Vector3 start = targetTransform.position;
        Vector3 dir = transform.position - targetTransform.position;

        float dist = CamOffset.z * -1;
        Debug.DrawRay(targetTransform.position, dir, Color.green);
        if(Physics.Raycast(targetTransform.position, dir, out hit, dist, wallLayer))
        {
            float hitDist = hit.distance;
            Vector3 sphereCastCenter =  targetTransform.position + (dir.normalized * hitDist);
            transform.position = sphereCastCenter;

        }
    }

}