# ParticleSystemForceField > Script interface for Particle System Force Fields. ## Definition * **Type:** Class * **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md) * **Assembly:** UnityEngine.ParticleSystemModule * **Inherits from:** [Behaviour](/engine/6000.7/script-reference/unityengine/behaviour.md) ```csharp [RequireComponent(typeof(Transform))] public class ParticleSystemForceField : Behaviour ``` ## Remarks Particle System Force Fields can be used to influence groups of particles that enter each field's zone of influence. The shape of the Force Field can be set to a variety of shapes, and how the particles are affected is controlled by various properties in the Force Field. As part of choosing the shape, you may define a start and end range. The end range describes the maximum extent of the shape, and the start range can be used to create a hollow shape. A number of forces can be applied to particles that are within this volume: directional, gravitational, rotational, drag, and a vector field. The settings for each type of force make use of the [ParticleSystem.MinMaxCurve](/engine/6000.7/script-reference/unityengine/particlesystem/minmaxcurve.md) type, which is also used in the Particle System. This type allows you to set simple uniform values, or more complicated values that vary per-particle, and vary over the lifetime of each particle. ## Examples ```csharp using System; using System.Collections; using System.Collections.Generic; using System.Linq; using UnityEngine; [RequireComponent(typeof(ParticleSystem))] public class ExampleClass : MonoBehaviour { public ParticleSystemForceFieldShape m_Shape = ParticleSystemForceFieldShape.Sphere; public float m_StartRange = 0.0f; public float m_EndRange = 3.0f; public Vector3 m_Direction = Vector3.zero; public float m_Gravity = 0.0f; public float m_GravityFocus = 0.0f; public float m_RotationSpeed = 0.0f; public float m_RotationAttraction = 0.0f; public Vector2 m_RotationRandomness = Vector2.zero; public float m_Drag = 0.0f; public bool m_MultiplyDragByParticleSize = false; public bool m_MultiplyDragByParticleVelocity = false; private ParticleSystemForceField m_ForceField; void Start() { // Create a Force Field var go = new GameObject("ForceField", typeof(ParticleSystemForceField)); go.transform.position = new Vector3(0, 2, 0); go.transform.rotation = Quaternion.Euler(new Vector3(90.0f, 0.0f, 0.0f)); m_ForceField = go.GetComponent(); // Configure Particle System transform.position = new Vector3(0, -4, 0); transform.rotation = Quaternion.identity; var ps = GetComponent(); var main = ps.main; main.startSize = new ParticleSystem.MinMaxCurve(0.05f, 0.2f); main.startSpeed = new ParticleSystem.MinMaxCurve(1.5f, 2.5f); main.maxParticles = 100000; var emission = ps.emission; emission.rateOverTime = 0.0f; emission.burstCount = 1; emission.SetBurst(0, new ParticleSystem.Burst(0.0f, 200, 200, -1, 0.1f)); var shape = ps.shape; shape.shapeType = ParticleSystemShapeType.SingleSidedEdge; shape.radius = 5.0f; shape.radiusMode = ParticleSystemShapeMultiModeValue.BurstSpread; shape.randomPositionAmount = 0.1f; shape.randomDirectionAmount = 0.05f; var forces = ps.externalForces; forces.enabled = true; } void Update() { m_ForceField.shape = m_Shape; m_ForceField.startRange = m_StartRange; m_ForceField.endRange = m_EndRange; m_ForceField.directionX = m_Direction.x; m_ForceField.directionY = m_Direction.y; m_ForceField.directionZ = m_Direction.z; m_ForceField.gravity = m_Gravity; m_ForceField.gravityFocus = m_GravityFocus; m_ForceField.rotationSpeed = m_RotationSpeed; m_ForceField.rotationAttraction = m_RotationAttraction; m_ForceField.rotationRandomness = m_RotationRandomness; m_ForceField.drag = m_Drag; m_ForceField.multiplyDragByParticleSize = m_MultiplyDragByParticleSize; m_ForceField.multiplyDragByParticleVelocity = m_MultiplyDragByParticleVelocity; } void OnGUI() { GUIContent[] shapeLabels = Enum.GetNames(typeof(ParticleSystemForceFieldShape)).Select(n => new GUIContent(n)).ToArray(); m_Shape = (ParticleSystemForceFieldShape)GUI.SelectionGrid(new Rect(25, 25, 400, 25), (int)m_Shape, shapeLabels, 4); float y = 80.0f; float spacing = 40.0f; GUI.Label(new Rect(25, y, 140, 30), "Start Range"); m_StartRange = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_StartRange, 0.0f, 2.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "End Range"); m_EndRange = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_EndRange, 2.0f, 3.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Direction"); m_Direction.x = GUI.HorizontalSlider(new Rect(165, y + 5, 40, 30), m_Direction.x, -1.0f, 1.0f); m_Direction.y = GUI.HorizontalSlider(new Rect(210, y + 5, 40, 30), m_Direction.y, -1.0f, 1.0f); m_Direction.z = GUI.HorizontalSlider(new Rect(255, y + 5, 40, 30), m_Direction.z, -1.0f, 1.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Gravity"); m_Gravity = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_Gravity, -0.05f, 0.05f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Gravity Focus"); m_GravityFocus = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_GravityFocus, 0.0f, 1.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Rotation Speed"); m_RotationSpeed = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_RotationSpeed, -10.0f, 10.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Rotation Attraction"); m_RotationAttraction = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_RotationAttraction, 0.0f, 0.01f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Rotation Randomness"); m_RotationRandomness.x = GUI.HorizontalSlider(new Rect(165, y + 5, 60, 30), m_RotationRandomness.x, 0.0f, 1.0f); m_RotationRandomness.y = GUI.HorizontalSlider(new Rect(230, y + 5, 60, 30), m_RotationRandomness.y, 0.0f, 1.0f); y += spacing; GUI.Label(new Rect(25, y, 140, 30), "Drag"); m_Drag = GUI.HorizontalSlider(new Rect(165, y + 5, 100, 30), m_Drag, 0.0f, 20.0f); y += spacing; m_MultiplyDragByParticleSize = GUI.Toggle(new Rect(25, y, 220, 30), m_MultiplyDragByParticleSize, "Multiply Drag by Particle Size"); y += spacing; m_MultiplyDragByParticleVelocity = GUI.Toggle(new Rect(25, y, 220, 30), m_MultiplyDragByParticleVelocity, "Multiply Drag by Particle Velocity"); y += spacing; } } ``` ## Properties | Property | Description | | ---------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [directionX](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/directionx.md) | Apply a linear force along the local X axis to particles within the volume of the Force Field. | | [directionY](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/directiony.md) | Apply a linear force along the local Y axis to particles within the volume of the Force Field. | | [directionZ](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/directionz.md) | Apply a linear force along the local Z axis to particles within the volume of the Force Field. | | [drag](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/drag.md) | Apply drag to particles within the volume of the Force Field. | | [endRange](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/endrange.md) | Determines the size of the shape used for influencing particles. | | [gravity](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/gravity.md) | Apply gravity to particles within the volume of the Force Field. | | [gravityFocus](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/gravityfocus.md) | When using the gravity force, set this value between 0 and 1 to control the focal point of the gravity effect. | | [length](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/length.md) | Describes the length of the Cylinder when using the Cylinder Force Field shape to influence particles. | | [multiplyDragByParticleSize](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/multiplydragbyparticlesize.md) | When using Drag, the drag strength will be multiplied by the size of the particles if this toggle is enabled. | | [multiplyDragByParticleVelocity](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/multiplydragbyparticlevelocity.md) | When using Drag, the drag strength will be multiplied by the speed of the particles if this toggle is enabled. | | [rotationAttraction](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/rotationattraction.md) | Controls how strongly particles are dragged into the vortex motion. | | [rotationRandomness](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/rotationrandomness.md) | Apply randomness to the Force Field axis that particles will travel around. | | [rotationSpeed](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/rotationspeed.md) | The speed at which particles are propelled around a vortex. | | [shape](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/shape.md) | Selects the type of shape used for influencing particles. | | [startRange](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/startrange.md) | Setting a value greater than 0 creates a hollow Force Field shape. This will cause particles to not be affected by the Force Field when closer to the center of the volume than the startRange property. | | [vectorField](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/vectorfield.md) | Apply forces to particles within the volume of the Force Field, by using a 3D texture containing vector field data. | | [vectorFieldAttraction](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/vectorfieldattraction.md) | Controls how strongly particles are dragged into the vector field motion. | | [vectorFieldSpeed](/engine/6000.7/script-reference/unityengine/particlesystemforcefield/vectorfieldspeed.md) | The speed at which particles are propelled through the vector field. | ## Inheritance **Inherited Members:** * [Behaviour.enabled](/engine/6000.7/script-reference/unityengine/behaviour/enabled.md) * [Behaviour.isActiveAndEnabled](/engine/6000.7/script-reference/unityengine/behaviour/isactiveandenabled.md) * [Component.GetComponent(Type)](/engine/6000.7/script-reference/unityengine/component/getcomponent.md#getcomponent\(type\)) * [Component.GetComponent\()](/engine/6000.7/script-reference/unityengine/component/getcomponent.md) * [Component.TryGetComponent(Type, Component)](/engine/6000.7/script-reference/unityengine/component/trygetcomponent.md) * [Component.TryGetComponent\(T)](/engine/6000.7/script-reference/unityengine/component/trygetcomponent.md) * [Component.GetComponent(string)](/engine/6000.7/script-reference/unityengine/component/getcomponent.md#getcomponent\(string\)) * [Component.GetComponentInChildren(Type, bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentinchildren.md#getcomponentinchildren\(type-bool\)) * [Component.GetComponentInChildren(Type)](/engine/6000.7/script-reference/unityengine/component/getcomponentinchildren.md#getcomponentinchildren\(type\)) * [Component.GetComponentInChildren\(bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentinchildren.md) * [Component.GetComponentsInChildren(Type, bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinchildren.md) * [Component.GetComponentsInChildren\(bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinchildren.md#getcomponentsinchildrent\(bool\)) * [Component.GetComponentsInChildren\(bool, List\)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinchildren.md) * [Component.GetComponentsInChildren\()](/engine/6000.7/script-reference/unityengine/component/getcomponentsinchildren.md#getcomponentsinchildrent\(\)) * [Component.GetComponentsInChildren\(List\)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinchildren.md) * [Component.GetComponentInParent(Type, bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentinparent.md#getcomponentinparent\(type-bool\)) * [Component.GetComponentInParent(Type)](/engine/6000.7/script-reference/unityengine/component/getcomponentinparent.md#getcomponentinparent\(type\)) * [Component.GetComponentInParent\(bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentinparent.md#getcomponentinparentt\(bool\)) * [Component.GetComponentInParent\()](/engine/6000.7/script-reference/unityengine/component/getcomponentinparent.md#getcomponentinparentt\(\)) * [Component.GetComponentsInParent(Type, bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinparent.md) * [Component.GetComponentsInParent\(bool)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinparent.md#getcomponentsinparentt\(bool\)) * [Component.GetComponentsInParent\(bool, List\)](/engine/6000.7/script-reference/unityengine/component/getcomponentsinparent.md) * [Component.GetComponentsInParent\()](/engine/6000.7/script-reference/unityengine/component/getcomponentsinparent.md#getcomponentsinparentt\(\)) * [Component.GetComponents(Type)](/engine/6000.7/script-reference/unityengine/component/getcomponents.md#getcomponents\(type\)) * [Component.GetComponents(Type, List\)](/engine/6000.7/script-reference/unityengine/component/getcomponents.md#getcomponents\(type-listcomponent\)) * [Component.GetComponents\(List\)](/engine/6000.7/script-reference/unityengine/component/getcomponents.md) * [Component.GetComponents\()](/engine/6000.7/script-reference/unityengine/component/getcomponents.md#getcomponentst\(\)) * [Component.GetComponentIndex()](/engine/6000.7/script-reference/unityengine/component/getcomponentindex.md) * [Component.CompareTag(string)](/engine/6000.7/script-reference/unityengine/component/comparetag.md#comparetag\(string\)) * [Component.CompareTag(TagHandle)](/engine/6000.7/script-reference/unityengine/component/comparetag.md#comparetag\(taghandle\)) * [Component.SendMessageUpwards(string, Object, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/sendmessageupwards.md#sendmessageupwards\(string-object-sendmessageoptions\)) * [Component.SendMessageUpwards(string, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/sendmessageupwards.md#sendmessageupwards\(string-sendmessageoptions\)) * [Component.SendMessage(string, Object)](/engine/6000.7/script-reference/unityengine/component/sendmessage.md#sendmessage\(string-object\)) * [Component.SendMessage(string)](/engine/6000.7/script-reference/unityengine/component/sendmessage.md#sendmessage\(string\)) * [Component.SendMessage(string, Object, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/sendmessage.md#sendmessage\(string-object-sendmessageoptions\)) * [Component.SendMessage(string, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/sendmessage.md#sendmessage\(string-sendmessageoptions\)) * [Component.BroadcastMessage(string, Object, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/broadcastmessage.md#broadcastmessage\(string-object-sendmessageoptions\)) * [Component.BroadcastMessage(string, SendMessageOptions)](/engine/6000.7/script-reference/unityengine/component/broadcastmessage.md#broadcastmessage\(string-sendmessageoptions\)) * [Component.transform](/engine/6000.7/script-reference/unityengine/component/transform.md) * [Component.transformHandle](/engine/6000.7/script-reference/unityengine/component/transformhandle.md) * [Component.gameObject](/engine/6000.7/script-reference/unityengine/component/gameobject.md) * [Component.tag](/engine/6000.7/script-reference/unityengine/component/tag.md) * [Object.GetEntityId()](/engine/6000.7/script-reference/unityengine/object/getentityid.md) * [Object.GetHashCode()](/engine/6000.7/script-reference/unityengine/object/gethashcode.md) * [Object.InstantiateAsync\(T)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, Transform, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, ReadOnlySpan\, ReadOnlySpan\)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Transform, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Transform, Vector3, Quaternion, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Transform, ReadOnlySpan\, ReadOnlySpan\)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Transform, ReadOnlySpan\, ReadOnlySpan\, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, InstantiateParameters, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, InstantiateParameters, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, Vector3, Quaternion, InstantiateParameters, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, Vector3, Quaternion, InstantiateParameters, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.InstantiateAsync\(T, int, ReadOnlySpan\, ReadOnlySpan\, InstantiateParameters, CancellationToken)](/engine/6000.7/script-reference/unityengine/object/instantiateasync.md) * [Object.Instantiate(Object, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object-vector3-quaternion\)) * [Object.Instantiate(Object, Vector3, Quaternion, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object-vector3-quaternion-transform\)) * [Object.Instantiate(Object)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object\)) * [Object.Instantiate(Object, Scene)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object-scene\)) * [Object.Instantiate\(T, InstantiateParameters)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate\(T, Vector3, Quaternion, InstantiateParameters)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate(Object, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object-transform\)) * [Object.Instantiate(Object, Transform, bool)](/engine/6000.7/script-reference/unityengine/object/instantiate.md#instantiate\(object-transform-bool\)) * [Object.Instantiate\(T)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate\(T, Vector3, Quaternion)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate\(T, Vector3, Quaternion, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate\(T, Transform)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Instantiate\(T, Transform, bool)](/engine/6000.7/script-reference/unityengine/object/instantiate.md) * [Object.Destroy(Object, float)](/engine/6000.7/script-reference/unityengine/object/destroy.md) * [Object.DestroyImmediate(Object, bool)](/engine/6000.7/script-reference/unityengine/object/destroyimmediate.md) * [Object.FindObjectsByType(Type)](/engine/6000.7/script-reference/unityengine/object/findobjectsbytype.md#findobjectsbytype\(type\)) * [Object.FindObjectsByType(Type, FindObjectsInactive)](/engine/6000.7/script-reference/unityengine/object/findobjectsbytype.md#findobjectsbytype\(type-findobjectsinactive\)) * [Object.DontDestroyOnLoad(Object)](/engine/6000.7/script-reference/unityengine/object/dontdestroyonload.md) * [Object.FindAnyObjectByType\()](/engine/6000.7/script-reference/unityengine/object/findanyobjectbytype.md#findanyobjectbytypet\(\)) * [Object.FindAnyObjectByType\(FindObjectsInactive)](/engine/6000.7/script-reference/unityengine/object/findanyobjectbytype.md#findanyobjectbytypet\(findobjectsinactive\)) * [Object.FindObjectsByType\()](/engine/6000.7/script-reference/unityengine/object/findobjectsbytype.md#findobjectsbytypet\(\)) * [Object.FindObjectsByType\(FindObjectsInactive)](/engine/6000.7/script-reference/unityengine/object/findobjectsbytype.md#findobjectsbytypet\(findobjectsinactive\)) * [Object.FindAnyObjectByType(Type)](/engine/6000.7/script-reference/unityengine/object/findanyobjectbytype.md#findanyobjectbytype\(type\)) * [Object.FindAnyObjectByType(Type, FindObjectsInactive)](/engine/6000.7/script-reference/unityengine/object/findanyobjectbytype.md#findanyobjectbytype\(type-findobjectsinactive\)) * [Object.ToString()](/engine/6000.7/script-reference/unityengine/object/tostring.md) * [Object.name](/engine/6000.7/script-reference/unityengine/object/name.md) * [Object.hideFlags](/engine/6000.7/script-reference/unityengine/object/hideflags.md) ### Operators | Operator | Description | | ---------------------------------------------------------------------------------- | ----------------------------------------------------------------------- | | [operator ==](/engine/6000.7/script-reference/unityengine/object/op-equality.md) | Compares two object references to see if they refer to the same object. | | [bool](/engine/6000.7/script-reference/unityengine/object/op-implicit.md) | Determines whether the object exists. | | [operator !=](/engine/6000.7/script-reference/unityengine/object/op-inequality.md) | Compares if two objects refer to a different object. |