using UnityEngine;
using System.Collections;

public class ChaseCamera : MonoBehaviour {

	public GameObject target;
	private Vector3 offset;

	void Start () {
		offset = transform.position - target.transform.position;
	}

	void Update () {
		transform.position = target.transform.position + offset;
	}
}

using UnityEngine;
using System.Collections;

public class ChaseCamera : MonoBehaviour {

	public GameObject target;
	private float smoothing = 2f;
	private Vector3 offset;

	void Start () {
		offset = transform.position - target.transform.position;
	}

	void Update () {

		Vector3 targetCamPos = target.transform.position + offset;

		transform.position =  Vector3.Lerp(transform.position, targetCamPos, smoothing * Time.deltaTime);
	}
}

using UnityEngine;
using System.Collections;

public class MainCamera : MonoBehaviour {

	public GameObject target;

	void LateUpdate(){

		// メインカメラをターゲットに向かせる。
		Camera.main.transform.LookAt(target.transform);
	}
}