Velocity Modules

Velocity modules exist to make adjustments to particle velocity in a variety of ways.

Initial Velocity

The Initial Velocity module sets the initial velocity of a particle. It contains the following member(s):

Property Description

Velocity

Start Velocity A vector distribution providing the velocity to apply to a particle at its spawn time. The value is retrieved using the EmitterTime of the owner emitter.
Start Velocity Radial A float distribution providing the velocity to apply to a particle along its radial direction. This direction is determined by the subtracting the location of the emitter from the particle location at spawn time. The value is retrieved using the EmitterTime of the owner emitter.
In World Space If true, the velocity is assumed to be in world-space.
Apply Owner Scale If true, the velocity value will be scaled by the ParticleSystemComponent's scale.

Initial Vel (Seed)

The Initial Vel (Seed) module is identical to the Initial Velocity module in that it sets the velocity of a particle when it is emitted; however, this module allows you to specify seed information to be used when choosing distribution values in order to provide a more consistent effect from the module each time the emitter is used. It contains the following member(s):

Property Description

RandomSeed

Random Seed Info The random seed(s) to use for selecting "random" values for this module's properties.
Property Description
Get Seed From Instance If true, the module will attempt to get the seed from the owner instance. If that fails, it will fall back to getting it from the Random Seeds array.
Instance Seed Is Index If true, the seed value retrieved from the instance will be an index into the Random Seeds array.
Parameter Name The name to expose to the placed instance for setting this seed.
Random Seeds The random seed values to utilize for this module. If multiple values are specified, a value will be chosen at random by the instance.
Reset Seed On Emitter Looping If true, the seed will be reset each time the emitter loops.

Velocity

Start Velocity A vector distribution providing the velocity to apply to a particle at its spawn time. The value is retrieved using the EmitterTime of the owner emitter.
Start Velocity Radial A float distribution providing the velocity to apply to a particle along its radial direction. This direction is determined by the subtracting the location of the emitter from the particle location at spawn time. The value is retrieved using the EmitterTime of the owner emitter.
In World Space If true, the velocity is assumed to be in world-space.
Apply Owner Scale If true, the velocity value will be scaled by the ParticleSystemComponent's scale.

Velocity Cone

The Velocity Cone module emits particles in the shape of a user-defined cone.

Property Description
Angle This float distribution value sets the angle of the cone shape. If set up as a Uniform, min represents the inner cone angle and max represents the outer. The value is [0..1] based, with 1 representing an angle of 180 degrees, or a complete sphere.
Velocity A float distribution sets the velocity of the particles as they are emitted along the cone.
Direction A 3D vector defining the direction points.

Velocity

In World Space If true, the velocity is assumed to be in world-space.
Apply Owner Scale If true, the velocity value will be scaled by the ParticleSystemComponent's scale.

Inherit Parent Velocity

Inherit Parent Velocity contributes the velocity of the parent (the particle emitter itself) to a particle when spawning. It contains the following member(s):

Property Description

Velocity

Scale A vector distribution that is applied to the parent velocity prior to adding it to the particle velocity during the spawn. The value is retrieved using the RelativeTime of the particle.
In World Space If true, the velocity is assumed to be in world-space.
Apply Owner Scale If true, the velocity value will be scaled by the ParticleSystemComponent's scale.

Velocity/Life

The Velocity/Life module scales the velocity by a given amount over the lifetime of the particle. It contains the following member(s):

Property Description

Velocity

Absolute If true, the velocity will be set to the value in the distribution when true. This allows for directly setting the velocity of a particle at a given point of its lifetime. It is important to note that this setting will 'step on' any previous modules that affect velocity. It will also prevent the "Initial Velocity" module from contributing to the initial velocity of particles. If false, the velocity will be scaled by the value of the distribution.
Apply Owner Scale If true, the velocity value will be scaled by the ParticleSystemComponent's scale.
In World Space If true, the velocity is assumed to be in world-space.

Local-space emitters that are moving will see strange results.

Vel Over Life A vector distribution that is used as the scaling value applied to the velocity. The value is retrieved using the RelativeTime of the particle.
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