Light flickering

We want to have an effect for our flashlight, so that it seems, the batteries are low and the lamp is flickering sometimes.

To get such effect, we need a new C# script, so create a new folder in our Scripts folder and name it Effects. In there create a new C# script and name it LightFlicker.

Our LightFlicker class is a simple MonoBehaviour

using UnityEngine;
using System.Collections;

public class LightFlicker : MonoBehaviour {
    


}

First, we need to store the light intensity and the flicker intensity values

    public float lightIntensity;
    public float flickerIntensity;

Then we need our lighting time and our flicker time stored

    public float lightTime;
    public float flickerTime;

Next, we need a random generator and the reference to the Light component

    System.Random rg;

    Light flashlight;

In the Awake function, we create a new instance of our random generator and get the reference of the Light component

    void Awake() {
        rg = new System.Random();
        flashlight = GetComponent<Light>();
    }

In the Start function, we start a new Coroutine, Flicker, which flickers our light

    void Start() {
        StartCoroutine(Flicker());
    }

Our Coroutine Flicker runs an endless loop, at first, we set the intensity to our lightIntensity property value, then we wait light time seconds (with a little random variation), then we set a random value between 4 and 9 which is our flicker count value, then we loop flicker count times, in this loop, we set the flashlight intensity to a random value and wait a random time between 0 and the flicker time.

    IEnumerator Flicker() {
        while(true) {
            flashlight.intensity = lightIntensity;

            float lightingTime = lightTime + ((float)rg.NextDouble() - 0.5f);
            yield return new WaitForSeconds(lightingTime);

            int flickerCount = rg.Next(4, 9);

            for(int i = 0; i < flickerCount; i++) {
                float flickingIntensity = lightIntensity - ((float)rg.NextDouble() * flickerIntensity);
                flashlight.intensity = flickingIntensity;

                float flickingTime = (float)rg.NextDouble() * flickerTime;
                yield return new WaitForSeconds(flickingTime);
            }
        }
    }

Alright, this was it. Back in Unity, drop the LightFlicker class onto our Flashlight GameObject and then

• set the LightIntensity to 1.8
• set the FlickerIntensity to 1.5
• set the LightTime to 2
• set the FlickerTime to 0.08
  

Okay, if you run the game now, you should see the light flickering around :)

Next time, we let our character escape the maze

The complete LightFlicker class code looks like this

using UnityEngine;
using System.Collections;

public class LightFlicker : MonoBehaviour {

    public float lightIntensity;
    public float flickerIntensity;

    public float lightTime;
    public float flickerTime;

    System.Random rg;

    Light flashlight;

    void Awake() {
        rg = new System.Random();
        flashlight = GetComponent<Light>();
    }

    void Start() {
        StartCoroutine(Flicker());
    }

    IEnumerator Flicker() {
        while(true) {
            flashlight.intensity = lightIntensity;

            float lightingTime = lightTime + ((float)rg.NextDouble() - 0.5f);
            yield return new WaitForSeconds(lightingTime);

            int flickerCount = rg.Next(4, 9);

            for(int i = 0; i < flickerCount; i++) {
                float flickingIntensity = lightIntensity - ((float)rg.NextDouble() * flickerIntensity);
                flashlight.intensity = flickingIntensity;

                float flickingTime = (float)rg.NextDouble() * flickerTime;
                yield return new WaitForSeconds(flickingTime);
            }
        }
    }

}