A System refers to one or many Contexts that define a standalone part of a visual effect. A System can be a Particle System, a Particle Strip System, a Mesh, or a Spawn machine. In the graph view, a System draws a dashed line box around the Contexts that it consists of.
Multiple Systems can interact with each other within a Visual Effect Graph:
A Spawn System can spawn particles in one or many Particle Systems. This is the main method for spawning particles.
Particle Systems can use GPU Events to spawn particles in other particle systems. This alternate method can spawn particles from other particles based on simulation events such as the death of particle.
A Spawn System can enable and disable other Spawn Systems. This allows you to use a master Spawn System that manages other Spawn Systems to synchronize particle emission.
Creating System from templates
The Visual Effect Graph comes with pre-built System templates that you can add to your graph. To create a System from a template:
- Right Click in an empty space of your workspace and select Create Node.
- In The menu, select System.
- Select a template from the list.
System simulation spaces
Some Systems use a simulation space property to define the reference space that it uses to simulate its contents:
- Local space Systems simulate the effect locally to the GameObject that holds the Visual Effect component.
- World space Systems simulate the effect independently of the GameObject that holds the Visual Effect component.
Regardless of the System's simulation space, you can use Spaceable Properties to access Local or World Values.
Setting a System simulation space
A System displays its simulation space in the top-right corner of each Context it consists of. This is the System's simulation space identifier. If a Context does not use process anything that depends on simulation space, it does not display the simulation space identifier.
To change the simulation space for a System, click the System's simulation space identifier to cycle through the compatible spaces.
Simulation space identifiers in Properties
Some Spaceable Properties display a smaller version of the simulation space identifier. This does not change the System's simulation space, but instead allows you to express a value in a space that is different from the System's simulation space. For example, a System could simulate in world space but a Property could be a local position.