Particle effects

• Right click > Effects > Particle system
  • It can also be added to a Game Object as a component
• We use Modules to control behavior (under particle system)
  • The renderer contains the material
• You can loop or play on awake (depends on your needs)

use case

• We have the particle effects attached on the rocket, and have it turned on based on the things we collided into

[SerializeField] ParticleSystem successParticle;
[SerializeField] ParticleSystem crashParticle;
 
void OnCollisionEnter(Collision other)
{
	crashParticle.Play();
}

Laser beam (Argon Assault)

• Change Simulation space to world so that the laser can shoot off to a wider area
• Adjust rate over time to shoot more over time
• Just generally tweak the settings
  • Start Lifetime - how long each individual particle will exist before disappearing
    • Start Lifetime = 1 → each particle disappears after 1 second
  • Start Speed - how fast particles move when they’re first emitted
    • higher values make particles shoot out faster
  • Lifetime
• If you want the trails only and not the particles, then
  • Under Trails turn off Size affects width
  • Under Particle System set Start Size = 0

Using the laser as bullets

1. Ensure particle collision and message sending is on
   • Looks like this
     • Making the Type to World allows the lasers to bounce
     • If you want the lasers to not bounce, set Min Kill Speed to 1
2. Add a non-trigger collider to the target (enemy/obstacle)
3. Use OnParticleCollision() on the target

public class DestroyEnemy : MonoBehaviour
{
    // Start is called before the first frame update
    void OnParticleCollision(GameObject other)
    {
        // Debug.Log("Particle hit: " + other.name);
        if (other.CompareTag("enemy"))
        {
            Debug.Log("Im Here!");
            Destroy(other);
        }
    }
}

• Make sure that this script is attached to where the particlesystem is

Explosion particle

• Change to Particles > Standard Unlit so that it won’t use the legacy one
• Change shape to Cone
• Make Particle System > Duration between 0.3 and 1 (so explosion is quick) and turn off looping
• Particle System > Start color → explore with diff colors
• You can add Trails to make it look more like an explosion
• Adding some randomness
  • Select the Noise module

Instantiating particles and destroying them

• Basically just destroy gameobjects only if they’re manually instantiated like this

public class DestroyEnemy : MonoBehaviour
{
    [SerializeField] GameObject deathParticles;
    void OnParticleCollision(GameObject other)
    {
        // Debug.Log("Particle hit: " + other.name);
        if (other.CompareTag("enemy"))
        {
            Debug.Log("Im Here!");
 
            // Instantiate and get reference to the new particles
            GameObject newParticles = Instantiate(deathParticles, other.transform.position, Quaternion.identity);
            // Explicitly play the particle system
            newParticles.GetComponent<ParticleSystem>().Play();
            
            // get particle system duration
            float duration = newParticles.GetComponent<ParticleSystem>().main.duration;
            
            Destroy(newParticles, duration + 3f);
            Destroy(other);
        }
    }
}

• If “Play on Awake” is clicked, you don’t even need the .Play() part because it will already be played when instanstiated!