IndoorMaskEffect.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityStandardAssets.ImageEffects;

[ExecuteInEditMode]
public class IndoorMaskEffect : ImageEffectBase
{
	[SerializeField]
	float _showMaskTime = 0.3f;

	public LensManager<bool> showMaskLens = new LensManager<bool>((b) => LensUtils.AllTrue(b, false));

	Coroutine _showMaskRoutine = null;

	void OnEnable()
	{
		material.SetColor("_Color", material.GetColor("_Color").SetA(0f));
		showMaskLens.evaluateCallback += OnEvaluateShowMask;
	}

	void OnPostRender()
	{
		if(showMaskLens || _showMaskRoutine != null)
			Graphics.Blit(null as RenderTexture, material);
	}

	void OnEvaluateShowMask(bool show)
	{ _OnEvaluateShowMask(show, false); }

	void OnEvaluateShowMask(bool show, bool instant = false)
	{ _OnEvaluateShowMask(show, instant); }

	void _OnEvaluateShowMask(bool show, bool instant)
	{
		if (show)
			Show(instant);
		else
			Hide(instant);
	}

	void Show(bool instant)
	{
		if (_showMaskRoutine != null)
			StopCoroutine(_showMaskRoutine);

		_showMaskRoutine = StartCoroutine(ShowMaskRoutine(true, instant));
	}

	Coroutine Hide(bool instant)
	{
		if (_showMaskRoutine != null)
			StopCoroutine(_showMaskRoutine);

		_showMaskRoutine = StartCoroutine(ShowMaskRoutine(false, instant));
		return _showMaskRoutine;
	}

	IEnumerator ShowMaskRoutine(bool showMask, bool instant)
	{
		Color startColor = material.GetColor("_Color");
		Color endColor = startColor.SetA(showMask ? 1f : 0f);
	
		float timer = instant ? _showMaskTime : 0f;
		while(timer <= _showMaskTime)
		{
			timer += Time.deltaTime;

			float alpha = timer / _showMaskTime;
			material.SetColor("_Color", Color.Lerp(startColor, endColor, alpha));

			yield return null;
		}

		_showMaskRoutine = null;
	}

	protected override void OnDisable()
	{
		base.OnDisable();
		showMaskLens.evaluateCallback -= OnEvaluateShowMask;
	}
}