Unity implements Particle Systems with a component, so placing a Particle System in a Scene is a matter of adding a pre-made GameObject (menu: GameObject > Effects > Particle System) or adding the component to an existing GameObject (menu: Component > Effects > Particle System). Because the component is quite complicated, the Inspector is divided into a number of collapsible sub-sections or modules that each contain a group of related properties. Additionally, you can edit one or more systems at the same time using a separate Editor window accessed via the Open Window button in the Inspector. See documentation on the Particle System component and individual Particle System modules to learn more.
When a GameObject with a Particle System is selected, the Scene view contains a small Particle Effect panel, with some simple controls that are useful for visualising changes you make to the system’s settings.
The Playback Speed allows you to speed up or slow down the particle simulation, so you can quickly see how it looks at an advanced state. The Playback Time indicates the time elapsed since the system was started; this may be faster or slower than real time depending on the playback speed. The Particle Count indicates how many particles are currently in the system. The playback time can be moved backwards and forwards by clicking on the Playback Time label and dragging the mouse left and right. The buttons at the top of the panel can be used to pause and resume the simulation, or to stop it and reset to the initial state.
Many of the numeric properties of particles or even the whole Particle System can vary over time. Unity provides several different methods of specifying how this variation happens:
When you set a property to Curve or Random Between Two Curves, the Particle System Curves editor appears at the bottom of the Inspector:
To edit a curve, click and drag an end point or key to reshape the curve:
The Particle System Curves editor has the following buttons:
To edit the way in which the Particle System plays curves, click the cog next to a selected key and choose one of the following options:
Similarly, the Start Color property in the main module has the following options:
When you set the Gradient color for particles, the Gradient Editor appears:
Color properties in various modules are multiplied together per channel to calculate the final particle color result.
All particle properties are accessible by the Animation system, meaning you can keyframe them in and control them from your animations.
To access the Particle System’s properties, there must be an Animator component attached to the Particle System’s GameObject. An Animation Controller and an Animation are also required.
To animate a Particle System property, open the Animation Window with the GameObject containing the Animator and Particle System selected. Click Add Property to add properties.
Scroll to the right to reveal the add controls.
Note that for curves, you can only keyframe the overall curve multiplier, which can be found next to the curve editor in the Inspector.