Using the particle system
SpriteKit includes a powerful particle system that makes it easy to add exciting graphics to your game. Particle emitter nodes create many small instances of an image that are combined to create a great-looking effect. A very easy example of a particle system is Rain. Rain is a particle system, and each rain drop is a particle, and a cloud has a lot of emitters from where the droplets or particles are created.
We will create a particle system instead of just creating individual particles, because with a particle system you can create different kinds of effects using the same particle. For example, we saw Rain, which is a particle system; what if we wanted another effect, such as water coming out of the faucet? Here, the particle is the same—a water droplet—but a rain droplet behaves differently. Here, water is falling from the faucet; each drop falls with a force and is created with a single emitter—the faucet outlet. So, we can change the particle system to have...