# ParticleSystem.MainModule > Script interface for the MainModule of a Particle System. ## Definition * **Type:** Struct * **Namespace:** [UnityEngine](/engine/6000.5/script-reference/unityengine.md) * **Assembly:** UnityEngine.ParticleSystemModule ```csharp public struct ParticleSystem.MainModule ``` ## Remarks Additional Resources: [ParticleSystem](/engine/6000.5/script-reference/unityengine/particlesystem.md), [ParticleSystem.main](/engine/6000.5/script-reference/unityengine/particlesystem/main.md). ## Properties | Property | Description | | ------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [cullingMode](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/cullingmode.md) | Configure whether the Particle System will still be simulated each frame, when it is offscreen. | | [customSimulationSpace](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/customsimulationspace.md) | Simulate particles relative to a custom transform component. | | [duration](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/duration.md) | The duration of the Particle System in seconds. | | [emitterVelocity](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/emittervelocity.md) | The current Particle System velocity. | | [emitterVelocityMode](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/emittervelocitymode.md) | Control how the Particle System calculates its velocity, when moving in the world. | | [flipRotation](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/fliprotation.md) | Makes some particles spin in the opposite direction. | | [gravityModifier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/gravitymodifier.md) | A scale that this Particle System applies to gravity, defined either by [Physics.gravity](/engine/6000.5/script-reference/unityengine/physics/gravity.md) or \[Physics2D.gravity]]. | | [gravityModifierMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/gravitymodifiermultiplier.md) | Change the gravity multiplier. | | [gravitySource](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/gravitysource.md) | Specify whether to use the gravity strength from the 2D or 3D physics system. | | [loop](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/loop.md) | Specifies whether the Particle System is looping. | | [maxParticles](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/maxparticles.md) | The maximum number of particles to emit. | | [playOnAwake](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/playonawake.md) | If set to true, the Particle System automatically begins to play on startup. | | [prewarm](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/prewarm.md) | If [\_loop](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/loop.md) is true, when you enable this property, the Particle System looks like it has already simulated for one loop when first becoming visible. | | [ringBufferLoopRange](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/ringbufferlooprange.md) | When [ParticleSystem.MainModule.ringBufferMode](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/ringbuffermode.md) is set to loop, this value defines the proportion of the particle life that loops. | | [ringBufferMode](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/ringbuffermode.md) | Configure the Particle System to not kill its particles when their lifetimes are exceeded. | | [scalingMode](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/scalingmode.md) | Control how the Particle System applies its Transform component to the particles it emits. | | [simulationSpace](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/simulationspace.md) | This selects the space in which to simulate particles. It can be either world or local space. | | [simulationSpeed](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/simulationspeed.md) | Override the default playback speed of the Particle System. | | [startColor](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startcolor.md) | The initial color of particles when the Particle System first spawns them. | | [startDelay](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startdelay.md) | Start delay in seconds. | | [startDelayMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startdelaymultiplier.md) | A multiplier for [\_startDelay](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startdelay.md) in seconds. | | [startLifetime](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startlifetime.md) | The total lifetime in seconds that each new particle has. | | [startLifetimeMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startlifetimemultiplier.md) | A multiplier for [\_startLifetime](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startlifetime.md). | | [startRotation](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotation.md) | The initial rotation of particles when the Particle System first spawns them. | | [startRotation3D](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotation3d.md) | A flag to enable 3D particle rotation. | | [startRotationMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationmultiplier.md) | A multiplier for [\_startRotation](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotation.md). | | [startRotationX](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationx.md) | The initial rotation of particles around the x-axis when emitted. | | [startRotationXMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationxmultiplier.md) | The initial rotation multiplier of particles around the x-axis when the Particle System first spawns them. | | [startRotationY](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationy.md) | The initial rotation of particles around the y-axis when the Particle System first spawns them. | | [startRotationYMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationymultiplier.md) | The initial rotation multiplier of particles around the y-axis when the Particle System first spawns them.. | | [startRotationZ](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationz.md) | The initial rotation of particles around the z-axis when the Particle System first spawns them | | [startRotationZMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startrotationzmultiplier.md) | The initial rotation multiplier of particles around the z-axis when the Particle System first spawns them. | | [startSize](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsize.md) | The initial size of particles when the Particle System first spawns them. | | [startSize3D](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsize3d.md) | A flag to enable specifying particle size individually for each axis. | | [startSizeMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizemultiplier.md) | A multiplier for the initial size of particles when the Particle System first spawns them. | | [startSizeX](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizex.md) | The initial size of particles along the x-axis when the Particle System first spawns them. | | [startSizeXMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizexmultiplier.md) | A multiplier for [\_startSizeX](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizex.md). | | [startSizeY](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizey.md) | The initial size of particles along the y-axis when the Particle System first spawns them. | | [startSizeYMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizeymultiplier.md) | A multiplier for [\_startSizeY](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizey.md). | | [startSizeZ](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizez.md) | The initial size of particles along the z-axis when the Particle System first spawns them. | | [startSizeZMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizezmultiplier.md) | A multiplier for [\_startSizeZ](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startsizez.md). | | [startSpeed](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startspeed.md) | The initial speed of particles when the Particle System first spawns them. | | [startSpeedMultiplier](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startspeedmultiplier.md) | A multiplier for [\_startSpeed](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/startspeed.md). | | [stopAction](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/stopaction.md) | Select whether to Disable or Destroy the GameObject, or to call the [MonoBehaviour.OnParticleSystemStopped()](/engine/6000.5/script-reference/unityengine/monobehaviour/onparticlesystemstopped.md) script Callback, when the Particle System stops and all particles have died. | | [useUnscaledTime](/engine/6000.5/script-reference/unityengine/particlesystem/mainmodule/useunscaledtime.md) | When true, use the unscaled delta time to simulate the Particle System. Otherwise, use the scaled delta time. |