CameraControl.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// Attach to Main Camera of CametaCenter Empty GameObject child.
public class CameraControl : MonoBehaviour {
	
	private readonly float MAX_TURN_UP = 5f;
	private readonly float MAX_TURN_DOWN = 0f;
	private float InitPositionY = 0f;

	public GameObject DummyCenter; // PlayerのCenter位置にdummyを置く
	public GameObject TargetPlayer; // カメラが注目するPlayer
	private Player TargetPlayerScript;

	private float HorizonAngle  = 0f;
	private float VerticalAngle = 0f;
	[SerializeField]private float radius = 1f;


	private void Init () {
		TargetPlayerScript = TargetPlayer.GetComponent<Player> ();
		InitPositionY = transform.localPosition.y;
	}

	private void Awake () {
		Init ();
	}

	private void Update () {

		TrakingPlayer ();

		HorizonAngle += Input.GetAxis ("Horizontal");
		VerticalAngle = Input.GetAxis ("Vertical");

		if (HorizonAngle > 0.5f || HorizonAngle < 0.5f) {
			TurntoCenter (HorizonAngle, VerticalAngle);
		}

		if (Input.GetKey (KeyCode.Space)) {
			RotateReset ();
		}
	}

	// Function on Update.
	public void TrakingPlayer () {
		if (TargetPlayer != null) {
			DummyCenter.transform.position = TargetPlayer.transform.position;
		}
	}

	public void TurntoCenter (float dx, float heigh) {
		float x = Mathf.Cos (dx);
		float z = Mathf.Sin (dx);
		print ("x : " + x + ", y : " + z);

		transform.localPosition = Vector3.right * x * radius + Vector3.forward * z * radius + Vector3.up * transform.localPosition.y;


		if(transform.localPosition.y < InitPositionY + MAX_TURN_UP && heigh > 0)
			transform.localPosition += Vector3.up * heigh;

		if(transform.localPosition.y > MAX_TURN_DOWN && heigh < 0)
			transform.localPosition += Vector3.up * heigh;

		if (transform.position.y >= TargetPlayerScript.HeightToRoof)
			transform.position = Vector3.right * transform.position.x + Vector3.up * TargetPlayerScript.HeightToRoof + Vector3.forward * transform.position.z;
		
		transform.LookAt (TargetPlayer.transform.position);
	}

	public void RotateReset () {
		HorizonAngle = 0;
		VerticalAngle = 0;

		transform.localPosition = Vector3.one - Vector3.forward;
	}
}