Editor’s Picks – The particulars of particles!
From little motes of dust floating in the sunlight to the magnificence of a supernova, many magical little details of reality can be created with particle systems, the elegant, low-cost way to add detail and create visually compelling effects!
Particle systems are the primary rendering mechanism for simulating fire, gun effects, exploding barrels, fireworks, laser beams, bursts of energy, bursts of cartoon stars, shards of glass, shrapnel, magical spells and gory splashes of blood. When paired up with the right sound effects, the impact can be made even more immersive.
What’s a particle system?
At the core of a particle system is a gameobject with a particle emitter, a controller that allows you to design, configure, and control the particle effect. Many decisions need to be made in creating the perfect particle system. Should the particles be 2D textures or mesh? Should they face a specific camera? How quickly are they emitted, for how long, with what velocity? Do they change color, size, or opacity over time? Do they bounce off colliders? Do the particles fizzle and pop, then emit child particles?
It’s great fun to experiment with making particle systems from scratch, but it can also be time consuming and tricky to get just right. A solid particle system is a well-balanced cocktail combining beautiful artwork, masterfully tuned sets of behavioral properties and platform+performance considerations. You don’t have to be a particle systems scientist to get it right, because there are thousands of top-notch particle effects in the Asset Store. It’s stocked with ready-to-use particle systems capable of simulating almost any effect you need, designed by some of the best artists and technical directors in the industry. In addition to pre-configured prefabs, you’ll also find third party frameworks and tools for creating the perfect particle symphony.
Blowing stuff up!
Grab your flame suit, ear protection, and tinted safety goggles! There’s no point denying it: blowing stuff up in video games is incredibly fun. Because you’re not constrained by the laws of nature (or your local fire marshall), you can have megatons of megafun creating the most earth-shaking, shrapnel-blasting, and brain-vaporizing explosions.
My top pick: Flying Teapot from Japan is one of the best texture-sheet based particle smiths on the Asset Store. FT Explosion Master features twenty prefabs, each a master crafted explosion with beautiful smooth-flowing clouds of smoke, variable-sized ejecta and chunks of charred debris, and lovely dancing flames that would tickle the fancy of any pyromaniac.
General feedback on the collection is positive, but there is a strong sprite-sheet aspect to parts of the system, so certain aspects of the package may not be as customizable as another solution. However, Flying Teapot pay close attention to detail and energy flow, and any of these effects will add AAA quality detail and impact to your game.
Although relatively new to the Asset Store, MASSIVEART brings what I personally think are the best standalone prefab explosions out there. Like Flying Teapot’s offering above, MASSIVEART’s solution is built around sprite-sheets, with the same benefit of being incredibly fluid and photorealistic, but at the expense of some customizability. Small explosions, huge thermonuclear ones, campfires, flame throwers, a variety of smoke, and firewalls, this package is a blast to play with.
Asset Store publisher Unluck Software is one of the most prolific creators of content on the Asset Store. Their work includes models, particle systems, birds (and fish, bats, rats, butterflies..) with behavioral flocking, and audio. Not surprisingly, they’re the minds behind one of the most popular and beloved explosion and fire particle systems Fire FX. The package includes everything a firebug could desire in a cleanly-executed prefab form: realistic flames with sparks and smoke emission, explosions with shockwaves and backdraft, effects for flaming busted gas pipes, rings of fire, subterranean earth-scorching, as well as sizzling and searing flames with popping effects. Unlike some of the aforementioned packages, Unluck’s Fire FX doesn’t rely on sprite-sheets, making it a bit more flexible than others. If you’re really into customizing your explosions, it might be the right choice for you.
The Cartoon Universe
While many designers see photo-realism as the holy grail of realtime CG, many of us see games as a means to simulate things that would be impossible in real life. The universe of cartoons is a great middle road between the real and the impossible, integrating the symbols and language of reality but caricaturized, stylized, and unfettered by its dull constraints. Although they weren’t the first to do it, Nintendo popularized beautiful, high-quality cartoon particle effects with Legend of Zelda: The Wind Waker in 2002. The stylized particles of dust, sword strikes, flames, splashes of water, gusts of wind were so outstanding that they were perhaps more memorable than the gameplay itself. You can see the influence of Wind Waker in many of today’s games and similar stylized particles remain in demand to this day.
The Asset Store is packed with equally notable cartoon effects, but the undisputed King of Cartoon Particles is Jean Moreno, an artist and developer from France who has taken the Asset Store by storm with his amazing Cartoon FX Pack Series.
Moreno’s first Cartoon FX Pack, Volume 1, was heavily influenced by the visual language of comic books, combining chains of complex particle sequences with comic book action words. KA-POW! Moreno also innovated by including his CartoonFX Easy Editor with his kits, custom in-editor windows that are used to refine and customize his complete library of effects without having to fuss around at a lower level.
Another popular offering is Unluck Software’s FX Megapack. This handy package is a great deal priced under $10 and includes over 125 particle prefabs in mostly cartoon style. The system allows you to customize your effects, so you can change or remove cartoon action words if you desire.
If you’re inspired by the Japanese RPG gaming genre, you probably should get your hands on FX Quest by G.E. TeamDev. They’ve invested a lot of skill, time and energy in creating a set of more than 187 particle prefabs which faithfully recreate the visual effects that so strikingly define the look of the genre: magical attacks and spells, high-energy fireballs, the forces of nature, all bold, vivid, and easily customizable. The set includes a smart scaling tool and 22 UI-specific particle effects to add extra charm and life to your user experience.
Particle frameworks & external tools
I’ve just shown a couple of great particle system prefabs above, but what if you want to customize them further? Or create more sophisticated particle systems yourself? If you’re a DIY kind of particle expert, there’s a number of excellent frameworks and tools on the Asset Store which can help you do just that.
Particle Playground 2 is an intuitive and easy-to-use particle editing framework which sits atop and extends Unity’s existing Shuriken particle system. Polyfied extends the system with new properties, such as turbulent forces and attraction & repulsion to other entities, along with the ability to communicate with other particle systems and the game logic system.
Particle Playground 2 makes it easy to snapshot your favorite creations and set and transition between particle states which you set. You can also export and redistribute your particle creations as you see fit. The system is written in c#, takes advantage of multithreading, comes with several starter scenes and is available for all platforms that Unity supports.
PopcornFX particles are an industry standard, but require a framework you’ll need to purchase separately.
While sniffing around the Asset Store for particle effects you may have encountered a number of products from PopcornFX. They make fantastic particles and a great set of tools for particle design, but there’s one thing you need to know: PopcornFX uses its own proprietary particle rendering technology, instead of the core system included with Unity.
In order to use PopcornFX branded particles with Unity, you’ll need to first purchase the appropriate PopcornFX Particle Effects Plugin for each of your target platforms, such as desktop/console, Android or iOS. The cool thing about Popcorn is that you can author your effects in their own application custom-tailored for the design of particle systems. It’s pretty much the AAA industry standard tool for this kind of job, but the downside is the added expense. Personally, I think Unity’s own particle renderer is perfectly up to the job, although lots of folks feel the extra functionality is worth the higher price tag.
Fundamentally, particle systems are representations of the forces of nature at work, expressed in the transformation of small entities. Although that nature can be unlike anything that occurs in our world, it is nonetheless consistently following a set of rules. It’s interesting to see how these rules can be used to represent phenomena that we might not normally consider particulate, like fluids. Fluid dynamics can be very complex, but can be simulated pretty efficiently through the clever use of particles.
Fluvio by Thinksquirrel is a beautiful water and fluid simulator. By fine tuning properties such as viscosity, turbulence, and surface tension, it’s possible to create a fluid simulation for any occasion: thick and heavy lava, gloppy paint, or roiling water. Fluvio is far more than your everyday particle system, as it is driven by a sophisticated fluid dynamics engine and comes with some very convincing liquid shaders. At its core, however, Fluvio demonstrates how powerful particles really can be. In addition to being visually striking, Fluvio’s physics simulations open up worlds of possibilities for fluid-driven gameplay mechanics, such as puzzles operated by pipes, sluices and valves, physically accurate water wheels, and the behavior of buoyant objects. The folks at Thinksquirrel have gone out of their way to provide extensive video tutorials and have a number of free example projects on the Asset Store which you can use, disassemble, and tweak as you see fit.
For practicality’s sake, I’ve only demonstrated a few of the many exceptional particle systems in our Asset Store. Like lighting and audio, particle systems are detail-giving elements that can transform a boring or hollow-feeling level into something full of life and richness. A small puff of smoke coming from the chimney of an otherwise decorative building suggests someone is inside, living a life of their own. Fireflies buzzing around a forest suggest that nature is always going to run its course, regardless of your gameplay. While we may tune them out in reality, we subconsciously notice and accept these little processes in everyday life as part of the richness we expect in our perception. I strongly encourage you to experiment, have fun, and take advantage of the detail and impact particles can add to your level. They’re so much fun, I promise you will never become particle-bored.