This is an explosion effect that I made in the winter of 2021. It was made in Unity 2020.2.7 URP using the shuriken particle system. The textures used for the particles were made by me in Clip Studio Paint. This effect is composed of four parts: the core of the blast, a ring of smoke, plumes of debris, and an intial flash. Everything besides the flash uses a cloud material I created. The material has two clouds separated into 2 rows and the particle system will randomly decide which row to use. I did this because explosions are chaotic, and I wanted to reflect that by having varied particles for the smoke clouds.
Blast Core
The core of the blast is created by spawning particles in a tiny sphere and pushing them out rapidly, then dampening their speed quickly. This creates a sort of explosion motion while creating a clear shape that helps delineate the range of the explosion. The particles change color over time to represent the heat of the explosion dimming. They fade and get smaller with time so that it looks like the smoke is dissipating instead of popping out of existence.
Ring of Smoke
I use a ring of smoke in the explosion to represent dust particles getting pushed away when the bomb explodes against the ground. These particles use a lot of the same things as the core for the same reasons. The main difference here is the spawning shape. These particles use a circle spawning shape instead of a sphere, because they don’t need to move vertically. The interesting thing here is that the ring is actually composed of 6 particle systems with each using a 60 degree arc that combine to create the ring. I did this for two reasons. Firstly, if I had used one circle shape, it would create draw order issues where Unity doesn’t know which particle should be drawn on top, but that issue is avoided if you use multiple particle systems. The second benefit of splitting this into 6 particle systems is that it allows you to control the random spawning of particles better. If I had just used one ring with randomly distributed particles, there would be times where some parts of the ring would be sparsely populated with particles, while other parts are too dense. By splitting it into 6 parts I guarantee that each section of the ring will be full enough to read as a ring, while keeping the particles random so that it still looks organic.
Debris Plumes
These particle systems represent the plumes of debris that you see in explosions. They use the same color curve as the previous two particle systems. They also shrink over time for the same reasons as the previous two, though in this case I push the shrinking until much further on in the plume’s life time because that solved an issue where the smoke clouds were looking like dots towards the end of the particle system’s lifetime. Each plume is its own particle system. The effect is created by spawning 1 particle shooting upwards and using a gravity modifier to pull it towards the ground. Then I use a sub-emitter to create the trail of particles that follow behind the main one. The sub-emitter inherits the color and size of the main particle to keep everything consistent. The particles in the sub-emitter also shrink over time because that creates a nice curved trail. If I didn’t do that, the plumes would look like weird curved cylinders.
Explosion Flash
The last part of the effect is the explosion flash. This is a massive particle with a yellow emissive texture that flashes on screen for a couple frames right at the beginning of the explosion. It’s the simplest part of the effect, but an explosion just wouldn’t feel right without a flash. Put this together with all the previous parts and you get the full effect:
Sasha Bond-Harris 