Unity : click to go

ClickToGo.cs

using UnityEngine;
using System.Collections;

public class ClickToMove : MonoBehaviour {

    public GameObject terrain;
    public Rigidbody rbody;
    public Animator anim;

    Vector3 previousPosition;
    Vector3 targetPosition;
    Quaternion targetRotation;
    float speed;

    // Use this for initialization
    void Start ()
    {
        anim = GetComponent<Animator>();
        rbody = GetComponent<Rigidbody>();
        speed = 3.0f;
    }
	
	// Update is called once per frame
	void Update () {
        if (Input.GetButtonDown("Fire1"))
        {
            RaycastHit hit;
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            if (terrain.GetComponent<Collider>().Raycast(ray, out hit, Mathf.Infinity))
            {
                targetPosition = hit.point;
                //transform.LookAt(hit.point);
                targetRotation = Quaternion.LookRotation(targetPosition - transform.position, Vector3.up);
            }
        }

        if (targetPosition != new Vector3(0, 0, 0) && transform.position != targetPosition)
            move();
    }

    void move()
    {
        transform.position = Vector3.MoveTowards(transform.position, targetPosition, Time.deltaTime * speed);
        transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.deltaTime * 10f);
    }
}