A Modular Approach to Particle Effects
The primary concept of Cascade was to make the creation of effects modular whenever possible. Cascade achieved this by supplying a default set of modules when any new effect was created, as well as providing tools to add additional modules or entirely new emitters based on what the visual effect artist needed to achieve. While this system worked well for many years, it had some issues that made certain tasks time-consuming and prone to error, such as sharing data between effects, or updating many effects at once.
A Cascade Particle System is made up of a collection of emitters.
Niagara addresses those issues by fully embracing modularity. Niagara separates the individual emitters that make up a particle system. Instead of having the particle system contain each emitter, Niagara Systems are comprised of many individual Niagara Emitters. Each of these Niagara Emitters contains a single effect controlled using modules you are familiar with, such as Lifetime, Location and Size,and these modules adjust how the particles look and behave. However, because these Niagara Emitters are independent actors saved in the Content Browser, they can be updated and shared with any Niagara System that you want to create. This means you can make changes to your emitters in less time.
A Niagara System is made up of a collection of Niagara Emitters.