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Unity Engine


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Script Reference

Unity Engine


Main module reference

Explore properties on the Main module, to configure the initial state of new particles.
Read time 4 minutesLast updated 21 days ago

The Particle System module contains global properties that affect the whole system. Most of these properties control the initial state of newly created particles.
The name of the module appears in the inspector as the name of the GameObject that the Particle System component is attached to.

Properties

For some properties in this section, you can use different modes to set their value. For information on the modes you can use, refer to Vary Particle System properties over time.

Property

Function

DurationThe length of time the system runs.
LoopingIf enabled, the system starts again at the end of its duration time and continues to repeat the cycle.
PrewarmIf enabled, the system is initialized as though it had already completed a full cycle (only works if Looping is also enabled).
Start DelayDelay in seconds before the system starts emitting once enabled.
Start LifetimeThe initial lifetime for particles.
Start SpeedThe initial speed of each particle in the appropriate direction.
3D Start SizeEnable this if you want to control the size of each axis separately.
Start SizeThe initial size of each particle.
3D Start RotationEnable this if you want to control the rotation of each axis separately.
Start RotationThe initial rotation angle of each particle.
Flip RotationCauses some particles to spin in the opposite direction.
Start ColorThe initial color of each particle.
Gravity ModifierScales the gravity value set in the Physics window. A value of zero switches gravity off.
Simulation SpaceControls whether particles are animated in the parent object’s local space (therefore moving with the parent object), in the world space, or relative to a custom object (moving with a custom object of your choosing).
Simulation SpeedAdjust the speed at which the entire system updates.
Delta TimeChoose between Scaled and Unscaled, where Scaled uses the Time Scale value in the Time window, and Unscaled ignores it. This is useful for Particle Systems that appear on a Pause Menu, for example.
Scaling ModeChoose how to use the scale from the transform. Set to Hierarchy, Local or Shape. Local applies only the Particle System transform scale, ignoring any parents. Shape mode applies the scale to the start positions of the particles, but does not affect their size.
Play on AwakeIf enabled, the Particle System starts automatically when the object is created.
Emitter VelocityChoose how the Particle System calculates the velocity used by the Inherit Velocity and Emission modules. The system can calculate the velocity using a Rigidbody component, if one exists, or by tracking the movement of the Transform component. If no Rigidbody component exists, the system uses its Transform component by default.
Max ParticlesThe maximum number of particles in the system at once. If the limit is reached, some particles are removed.
Auto Random SeedIf enabled, the Particle System looks different each time it is played. When set to false, the system is exactly the same every time it is played.
Random SeedWhen disabling the automatic random seed, this value is used to create a unique repeatable effect.
Stop ActionWhen all the particles belonging to the system have finished, it is possible to make the system perform an action. A system is determined to have stopped when all its particles have died, and its age has exceeded its Duration. For looping systems, this only happens if the system is stopped via script.
    DisableThe GameObject is disabled.
    DestroyThe GameObject is destroyed.
    CallbackThe OnParticleSystemStopped callback is sent to any scripts attached to the GameObject.
Culling ModeChoose whether to pause Particle System simulation when particles are offscreen. Culling when offscreen is most efficient, but you may want to continue simulation for off-one effects.
    AutomaticLooping systems use Pause, and all other system use Always Simulate.
    Pause And Catch-upThe system stops simulating while offscreen. When re-entering the view, the simulation performs a large step to reach the point where it would have been had it not paused. In complex systems, this option can cause performance spikes.
    PauseThe system stops simulating while offscreen.
    Always SimulateThe system processes its simulation on each frame, regardless of whether it is on screen or not. This can be useful for one-shot effects such as fireworks, where during the simulation would be obvious.
Ring Buffer ModeKeeps particles alive until they reach the Max Particles count, at which point new particles recycle the oldest ones, instead of removing particles when their lifetimes elapse.
    DisabledDisable Ring Buffer Mode, so the system removes particles when their lifetime elapses.
    Pause Until ReplacedPauses old particles at the end of their lifetime until the Max Particle limit is reached, at which point the system recycles them, so they reappear as new particles.
    Loop Until ReplacedAt the end of their lifetime, particles rewind back to the specified proportion of their lifetime until the Max Particle limit is reached, at which point the system recycles them, so they reappear as new particles.