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Lumberyard
User Guide (Version 1.14)

Beam Emitter (CPU)

The Beam emitter spawns a length of connected particles at once, based on the origin and specified target position. You can also set wave form attributes to shape or animate the beam.

The following are parameters for the Beam emitter (CPU).

Beam Emitter Parameters for CPU Attributes

Parameter Description
Beam Lifetime Sets the beam lifetime, in seconds. You must use this in conjunction with particle lifetime.

Valid values: 0+

Default value: 1

Target Position Specifies the XYZ position to set the beam target, offset from the origin.

Default value: 0, 0, 15

Random Target Offset Randomizes the XYZ beam target, offset from the target position.

Valid values: any

Default value: 0, 0, 0

Segment Type Specifies how each segment generates over the length of the beam. Use Fixed to set the number of segments over the length. Use Length to set the length of each segment over the beam length.

Valid values: Fixed, Length

Default value: Fixed

Segment Count Defines the number of segments with the Fixed type set.

Valid values: 0+

Default value: 10

Segment Length Defines the length of each segment with the Length type set.

Valid values: 0+

Default value: 5

Texture Shift Shifts the texture coordinate in the V direction at the specified rate.

Valid values: 0+

Default value: 0

Up Vector for Waves Specifies the XYZ vector on which the waveform occurs.

Valid values: any

Default value: 0, 0, 0

Wave Form Source Specifies the side of the beam from which to generate the waveform.
  • Origin – Waveform is calculated from the emitter origin.

  • Target – Waveform is calculated from the target specified by the target attributes.

Default value: Origin

Wave Form Type Sets the behavior for the waveform.
  • None – No waveform is used.

  • Sine – A periodic waveform generates a smooth, repetitive curve.

  • Square – A nonsinusoidal, periodic waveform in which the amplitude alternates.

  • Noise – A repetitive waveform with a randomized amplitude.

Default value: None

Wave Phase Sets the position of the waveform at the specified source. A value of 360 completes one full cycle of the waveform. You can animate the beam waveform by using Emitter Lifetime, Pulse Period, and Strength over Emitter Lifetime in conjunction.

Note

The beam animation is updated when a new one is spawned based on the Beam Lifetime parameter. A lower lifetime provides a smoother animation.

The following example demonstrates the wave phase parameter: Beam lifetime = .01, Emitter lifetime = 2, Pulse period = 2, Up vector = 1, 0, 0, Wave form type = Sine, wave phase = 180 (with a curve set on Strength over Emitter Lifetime), Wave amplitude = 2, Wave frequency = 0.5

Valid values: 0+

Default value: 0

Wave Amplitude Sets the strength of the waveform deformation.

Valid values: 0+

Default value: 0

Wave Frequency Sets the number of wave cycles over the waveform length.

Valid values: 0+

Default value: 0

Texture Mapping

Maps the assigned texture to each particle quad or across the trail stream.

  • Per Particle – Texture is mapped on each quad.

  • Per Stream – Texture is mapped over the length of the beam.

Default value: Per Particle

Note

When there is a single light source, some or all particles for Trail emitters can appear unlit (black). This is most apparent when the sun is the only light source and the time and day setting is noon. To address this:

  1. Add an Environment Probe to the scene to create indirect lighting. For more information, see Environment Probe.

  2. Enable Environment Probe Lighting on the particle system by specifying a value for the Environment Probe Lighting parameter. For example, a value of 0.5 applies light from the Environment Probe at half intensity. For more information, see Lighting Attribute.