prevent glitching camera

Unity Engine
1

Hey, first of all, i am a programming noob and i have written my own third person camera script. My problem is: i have no idea how i prevent glitching through walls.
Sorry for my poor english!

This is my ThirdPersonCameraScript.cs:

using UnityEngine;
using System.Collections;

public class thirdPersonCamera : MonoBehaviour {

    public Transform cameraTarget;
    public Texture2D crossHair;
    public float distance = 2.0f;

    public float xSpeed = 200.0f;
    public float ySpeed = 100.0f;

    public float yMinLimit = -40.0f;
    public float yMaxLimit = 40.0f;

    public float zoomMinLimit = 1.0f;
    public float zoomMaxLimit = 2.5f;

    private float rotationX = 0.0f;
    private float rotationY = 0.0f;

	void Start () {

        Vector3 angles = transform.eulerAngles;
        rotationY = angles.x;
        rotationX = angles.y;
	
	}

    void OnGUI () {

        GUI.DrawTexture(new Rect(Screen.width / 2 + 25, Screen.height / 2 + 25, 50, 50), crossHair, ScaleMode.ScaleToFit, true, 1.0F);

    }

    void Update () {

        if (Input.GetAxis("Mouse ScrollWheel") > 0  distance > zoomMinLimit)
        {
            distance = distance - 1 / (xSpeed * 0.02f);
        }

        if (Input.GetAxis("Mouse ScrollWheel") < 0  distance < zoomMaxLimit)
        {
            distance = distance + 1 / (xSpeed * 0.02f);
        }

        rotationX += Input.GetAxis("Mouse X") * xSpeed * 0.02f;
        rotationY -= Input.GetAxis("Mouse Y") * ySpeed * 0.02f;
        rotationY = Mathf.Clamp(rotationY, yMinLimit, yMaxLimit);

        Vector3 lol = new Vector3(0.0f, 0.0f, -distance);

        Quaternion cameraRotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(rotationY, rotationX, 0), Time.smoothDeltaTime * 3);
        Vector3 cameraPosition = cameraRotation * lol + cameraTarget.position;

        transform.rotation = cameraRotation;
        transform.position = cameraPosition;
    }
}

Can somebody help me please?

2

Check out “spherecast” for cameras, try googling it.