CameraManager - 2

CameraManager.cs

using UnityEngine;
using System.Collections;

[RequireComponent(typeof(Camera))]
public class CameraManager : MonoBehaviour {
	private Quaternion fromRotation;
	private Vector3 fromPosition;
	private float fromFov;
	private float fromNear;
	private float fromFar;

	private Camera toCamera;

	private float interpolationTime;
	private float interpolationTimeAccum;

	private Transform target;
	private Camera cachedCamera;

	void Awake() {
		cachedCamera = GetComponent< Camera >();
	}

	public static void EnableComponents(Camera _cam, bool _value) {
		_cam.enabled   = _value;
		
		AudioListener toCameraAudioListener = _cam.GetComponent< AudioListener >();
		if(toCameraAudioListener != null) {
			toCameraAudioListener.enabled = _value;
		}
	}

	public void InterpolateTo(Camera _toCamera, Transform _target, float _time) {
		if(_target == null) {
			_target = _toCamera.transform;
		}
		
		//Update From Camera values
		if (toCamera != null) { //Check if the previous target camera is still there to interpolate from it
			EnableComponents(toCamera, false);
			if(interpolationTimeAccum >= interpolationTime) {
				//we don't need to care about this is the interpolation is not finished since this camera if currently being updated
				transform.position = toCamera.transform.position;
				transform.rotation = toCamera.transform.rotation;
				cachedCamera.fieldOfView = toCamera.fieldOfView;
				cachedCamera.nearClipPlane = toCamera.nearClipPlane;
				cachedCamera.farClipPlane = toCamera.farClipPlane;
			}
		} else {
			//Set interpolation time to 0 if there isn't any Camera to interpolate from
			_time = 0.0f;
		}

		target = _target;

		fromRotation = transform.rotation;
		fromPosition = -transform.worldToLocalMatrix.MultiplyPoint(target.position); //translation from target to current camera position (in camera local)
		fromFov = cachedCamera.fieldOfView;
		fromNear = cachedCamera.nearClipPlane;
		fromFar = cachedCamera.farClipPlane;

		//Update To Camera values
		toCamera = _toCamera;
		EnableComponents(toCamera, false);

		//Activate interpolator
		gameObject.SetActive(true);
		
		//Restet time
		interpolationTime = _time;
		interpolationTimeAccum = 0.0f;
	}
	
	void Refresh() {
		float t = interpolationTimeAccum / interpolationTime;

		//Update camera paramenters
		cachedCamera.fieldOfView   = Mathf.Lerp(fromFov,  toCamera.fieldOfView,   t);
		cachedCamera.nearClipPlane = Mathf.Lerp(fromNear, toCamera.nearClipPlane, t);
		cachedCamera.farClipPlane  = Mathf.Lerp(fromFar,  toCamera.farClipPlane,  t);

		//Rotate
		transform.rotation = Quaternion.Lerp(fromRotation, toCamera.transform.rotation, t);

		//Translate
		transform.position = target.position;//Place in target position
		Vector3 p0 = fromPosition;
		Vector3 p1 = -toCamera.transform.worldToLocalMatrix.MultiplyPoint(target.position);
		transform.Translate(Vector3.Lerp(fromPosition, p1, t));
	}

	void LateUpdate() {
		interpolationTimeAccum = Mathf.Clamp(interpolationTimeAccum + Time.deltaTime, 0.0f, interpolationTime);
		
		if(interpolationTimeAccum < interpolationTime) {
			Refresh();
		} else {
			gameObject.SetActive(false);
			EnableComponents(toCamera, true);
		} 
	}
}