Color and size over lifetime in Unity - Mini Project: Build & Apply

Color and size over lifetime

📖 Scenario: You are creating a simple particle effect in Unity. Each particle changes its color and size as it lives. This makes the effect look more natural and interesting.

🎯 Goal: Build a Unity script that changes a particle's color and size smoothly over its lifetime.

📋 What You'll Learn

Create a Unity script with a ParticleSystem component reference

Define color and size gradients over the particle lifetime

Apply these gradients to the particle system's main module

Print confirmation that the setup is complete

💡 Why This Matters

🌍 Real World

Particle effects like fire, smoke, or magic spells often change color and size over their lifetime to look realistic.

💼 Career

Game developers and interactive media creators use these techniques to make engaging visual effects.

1

Set up the ParticleSystem reference

Create a public variable called particleSystem of type ParticleSystem inside a new C# class called ColorSizeOverLifetime.

Unity

using UnityEngine;

public class ColorSizeOverLifetime : MonoBehaviour
{
    // Your code here
}

Need a hint?

Use public ParticleSystem particleSystem; inside the class.

2

Create color and size gradients

Inside the ColorSizeOverLifetime class, create two public variables: colorGradient of type Gradient and sizeCurve of type AnimationCurve.

Unity

using UnityEngine;

public class ColorSizeOverLifetime : MonoBehaviour
{
    public ParticleSystem particleSystem;
    // Create public Gradient called colorGradient
    // Create public AnimationCurve called sizeCurve
}

Need a hint?

Use public Gradient colorGradient; and public AnimationCurve sizeCurve;.

3

Apply color and size over lifetime

In the Start() method, get the colorOverLifetime and sizeOverLifetime modules from particleSystem. Set colorOverLifetime.color to colorGradient and sizeOverLifetime.size to sizeCurve.

Unity

using UnityEngine;

public class ColorSizeOverLifetime : MonoBehaviour
{
    public ParticleSystem particleSystem;
    public Gradient colorGradient;
    public AnimationCurve sizeCurve;

    void Start()
    {
        // Get colorOverLifetime module
        // Set its color to colorGradient
        // Get sizeOverLifetime module
        // Set its size to sizeCurve
    }
}

Need a hint?

Use particleSystem.colorOverLifetime and particleSystem.sizeOverLifetime modules and enable them.

4

Print confirmation message

Add a Debug.Log statement inside Start() that prints "Color and size over lifetime set!".

Unity

using UnityEngine;

public class ColorSizeOverLifetime : MonoBehaviour
{
    public ParticleSystem particleSystem;
    public Gradient colorGradient;
    public AnimationCurve sizeCurve;

    void Start()
    {
        var colorOverLifetime = particleSystem.colorOverLifetime;
        colorOverLifetime.enabled = true;
        colorOverLifetime.color = new ParticleSystem.MinMaxGradient(colorGradient);

        var sizeOverLifetime = particleSystem.sizeOverLifetime;
        sizeOverLifetime.enabled = true;
        sizeOverLifetime.size = new ParticleSystem.MinMaxCurve(1f, sizeCurve);

        // Print confirmation message
    }
}

Need a hint?

Use Debug.Log("Color and size over lifetime set!"); inside Start().