TransparencyFlash.cs

using UnityEngine;
using System.Collections;

public class TransparencyFlash : MonoBehaviour {

    public KeyCode increaseOpacityKey = KeyCode.E;
    public KeyCode decreaseOpacityKey = KeyCode.Q;
    public KeyCode increaseFrequencyKey = KeyCode.C;
    public KeyCode decreaseFrequencyKey = KeyCode.Z;
    public float opacity = 0.1f;
    public int flash_freq = 25;

    private float minOpacity = 0f;
    private float maxOpacity = 1f;   
    private float fadeSpeed = .1f;

    private int minFrequency = 0;
    private int maxFrequency = 75;
    private float frequencyUpdateDelay = .1f;


    private Material _material;
    private MeshRenderer m;

    int timer = 0;
    

    // Use this for initialization
    void Start () {
        m = GetComponent<MeshRenderer>();
        _material = GetComponent<MeshRenderer>().material;
        Color c = _material.color;
        c.a = opacity;
        _material.color = c;
    }
	
	void Update () {
        OpacityControls();
        FrequencyControls();
        Timer();
    }
    
    void OpacityControls()
    {
        if (Input.GetKey(increaseOpacityKey))
        {
            Color c = _material.color;
            opacity += Time.deltaTime * fadeSpeed;
            opacity = Mathf.Clamp(opacity, minOpacity, maxOpacity);
            c.a = opacity;
            _material.color = c;
        }
        if (Input.GetKey(decreaseOpacityKey))
        {
            Color c = _material.color;
            opacity -= Time.deltaTime * fadeSpeed;
            opacity = Mathf.Clamp(opacity, minOpacity, maxOpacity);
            c.a = opacity;
            _material.color = c;
        }
    }
    
    void FrequencyControls()
    {
        if (Input.GetKeyDown(increaseFrequencyKey))
        {
            flash_freq++; 
        }
        if (Input.GetKeyDown(decreaseFrequencyKey))
        {
            flash_freq--;
        }
        flash_freq = Mathf.Clamp(flash_freq, minFrequency, maxFrequency);
    }

    void Timer()
    {
        timer++;

        if (timer >= flash_freq)
        {
            Color c = _material.color;
            c.a = opacity;
            _material.color = c;
            timer = 0;
        }
        else
        {
            Color c = _material.color;
            c.a = 0;
            _material.color = c;
        }
    }
}