Unity Advanced: Particle Systems and Colliders

Name: Unity Advanced: Particle Systems and Colliders
Author: Ken Geary

Create particle systems for props and visual effects in Unity

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Course: On-Demand

Hello, welcome to this lesson in Unity. In these lessons, you'll learn about particle systems and will create a particle-based prop for our game. Particle systems are very popular in adding stunning visual effects in 3D content creation apps, as well as in game engines. Particles can be set up in 2D or 3D. Let's take a look at the default particle system and go over to most used settings and how they affect the particle's look. Create a new scene, select Basic built-in, we'll add a plane, and we'll frame it in the scene panel. Open the Materials folder and drag the floor material onto the plane, so it'll be easier to see the particles. We'll save the scene as particles, file save as, scene's folder, right-click in the hierarchy and select Effects, Particle System. If the particle system is selected, you'll see a plane in the scene panel, and a special particle panel will appear, allowing you to control the playback of the particles. Toggle on gizmo is shown in the upper right corner of the scene panel. This will show the visual gizmo as I control the particle emission. Press pause. Notice how each particle is outlined by a square. These are what are called texture cards, and the default particle material has a texture of a white dot with a fall-off to transparency. You can replace these textures with others, such as flame textures to create a fire effect. Typically, you only use the alpha transparency and control the color in the options, allowing you to create a controller shading, including changes in color and shading over time, as the particle travels. By default, these cards are set to always face the camera. As you see as they orbit around, they're always facing forward towards the camera. This saves a lot of memory and allows fast performance by not having to render all sides. You can, however, change the particles from cards actual mesh shapes. For instance, if you want to simulate a busy swarm of bees. In the inspector, the duration is how long the particles appear. By default, set to 5, set to 1 and play, and I can set it back to 5. It looks the same. By default, looping is checked on, so if we play the particles, they appear to run forever. If we uncheck loop, press play in the particle panel, and in 5 seconds, the particles will stop emitting. This may be used for a splash of water, for example. Turning on loop would be more for water running out of a faucet. The start lifetime is how long each particle stays on screen. Let's change the value to 0.1, and you can see the particles vanish very quickly, within the 10th of a second. The start speed is how fast the particles are emitted. Click and drag over where it starts speed. Actually, we're going to change the lifetime back to 1. So I click and drag to change the speed. Start color allows you to tint the color of the particles, which blends with the alpha channel of the texture. Click the color swatch to change to red. It won't change it back to white. The gravity modifier allows you to add a force to pull the particles up or down, so you can simulate gravity as you would if creating a fountain effect. So as you make the number bigger in the gravity modifier, the faster the particles are pulled down to the ground. We'll set this back to 0. We'll now move down to the options we can switch on and off, as well as adjust and customize. Two options you typically need to keep checked on are emission and renderer, unless you plan on controlling these values with code. Uncheck Emission. There are no particles emitted. Click it back on. Then click the bar to open the options for the setting. Change the rate over time to 1. Now there's only one particle emitted every second. Change this back to 10. You click the bar again to close the options and reduce clutter. Scroll down and uncheck renderer. Once again, no particles because we stopped rendering them. Check it back on and open the options bar by clicking on it. As mentioned earlier, the texture cards face the camera at all times. This is called Billboard Render Mode. Change this to mesh. And with the default cube mesh you can see the particle texture on all six sides of the cube outline. Click the circle to mesh this section and select sphere. Now we have what looks like bubbles. With only a few setting changes we can already see the power of particles. Change the render mode back to billboard. The render alignment allows you to change where the cards face. Change to world view and the cards only point in one direction. If you orbit around you can see this effect. Change this back to view. This way they're always facing the camera. Then we'll close the render options by clicking the bar. Scroll back up and uncheck shape. You still see particles emitted but now in a straight line. The shape allows you to spread out the particles and shapes like spheres and cones. Enable shape. Open the option bar by clicking on it. The default shape is cone. You can click and drag on the angle and radius to adjust how to spread out the particles. A shape such as a circle emits from the ground outwards. For example a swarm of ants. You can also add an upwards velocity to this which will be usable for fountain effects. Set the shape back to cone and close the options. Let's look at one more popular option. Check on color over lifetime. Click the color swatch and you will see a gradient editor where you can add points to the gradient by clicking on adjusting values. Top portion adds points for alpha or transparency. The bottom is for color. Click once in the middle and on the top and bottom of the gradient. Click the first top marker and set the alpha to zero. Do the same for the last top marker. In the scene panel zoom out to see all the particles and notice they are transparent when they start to fade up and fade out. Now click the gradient again and set a different color on the three bottom markers. I choose a blue, yellow and red and you can see the color changes as the particles travel. These are good starting settings to simulate effects like fire. Save the scene. In the next lesson we are going to learn how to add colliders that will interact with particles in Unity. Thanks for watching.

Advanced Provider : Ken Geary 3 Lessons · 22m in English

Course Description

In these lessons you’ll work with Unity particle systems. We will explore how to adjust particles to create different effects and add colliders that the particles will bounce off of. By the end of these lessons, you will be able to create custom particle systems.

You will learn how to import texture game assets using the Unity Asset Store. These imported textures will be added to particle sprites to create effects such as a freezing effect. We’ll discuss how a particle system works, including how to adjust the number of particles, the lifetime of the particles, and whether the particles will be affected by forces such as simulated gravity. You will learn how to create a fountain by using basic cylinders scaled and stacked to represent the fountain. Then you’ll add a particle system, changing the shape of the particle emission to better simulate a fountain effect. You’ll adjust the velocity of the particles to shoot upwards, and then apply gravity to bring the particles back down. Then you’ll set color and transparency to change over the lifetime of the particles and add collisions so the particles interact with the fountain structure to simulate splashing. A second particle system will be created using a one burst of particles shaped to a cylinder and mapped with a lava or lighting texture map and colorized and cycled to be used to indicate a player or NPC has been frozen.

What You'll Learn

Create custom Unity particle systems and adjust particles to produce different effects
Import texture game assets from the Unity Asset Store and apply them to particle sprites
Build a fountain effect using scaled, stacked cylinders with a particle system, adjusting emission shape, velocity, gravity, color, and transparency
Add particle colliders so particles bounce off and interact with structures to simulate splashing
Create a burst-based freeze effect particle system using a cylinder-shaped emission with a texture map
Write code to control particles

Key Takeaways

A particle system can be adjusted by changing the number of particles, their lifetime, and whether they are affected by forces such as simulated gravity.
Textures imported from the Unity Asset Store can be added to particle sprites to create effects such as a freezing effect.
A fountain effect is built by scaling and stacking basic cylinders, then adding a particle system whose emission shape, velocity, and gravity are adjusted, with collisions added so particles interact with the fountain structure.
A freeze effect is created from a single burst of particles shaped to a cylinder, mapped with a lava or lighting texture, then colorized and cycled to indicate a player or NPC has been frozen.
Setting color and transparency to change over the lifetime of the particles helps simulate realistic effects.

Frequently Asked Questions

What will I be able to do after completing this course?

By the end of the lessons you will be able to create custom particle systems, including a fountain effect and a freeze effect, add colliders that particles bounce off of, and write code to control particles.

Does this course cover importing assets?

Yes. You will learn how to import texture game assets using the Unity Asset Store and add those imported textures to particle sprites to create effects such as a freezing effect.

What topics are included in the lessons?

The lessons cover an Introduction to Particles, Adding Colliders, and Creating a Custom Particle Prefab.

How does the course explain particle systems?

It discusses how a particle system works, including how to adjust the number of particles, the lifetime of the particles, and whether the particles will be affected by forces such as simulated gravity.

How are colliders used in this course?

Colliders are added so that particles bounce off of them and interact with structures, for example so fountain particles collide with the fountain structure to simulate splashing.