Particle System

The particle system component specifies a particle emitter in 3D space.

The particle system component can be enabled or disabled using the toggle in the top-right of the component panel. When enabled, the particle system is added to the scene and rendered.

Properties

Property	Description
Auto Play	When checked, the particle system plays immediately when created. If this option is not checked, you must call the particle system component's play function from a script.
Particle Count	The maximum number of particles this particle system manages.
Lifetime	The time in seconds between particle creation and destruction.
Emission Rate	The lower bound of the time range that defines particle creation intervals. The next particle emission time is randomly selected between 'Emission Rate' and 'Emission Rate 2'.
Emission Rate2	The upper bound of the time range that defines particle creation intervals. The next particle emission time is randomly selected between 'Emission Rate' and 'Emission Rate 2'.
Start Angle	The lower bound of the initial particle rotation specified in degrees. For each particle, this angle is randomly selected between 'Start Angle' and 'Start Angle 2'.
Start Angle2	The upper bound of the initial particle rotation specified in degrees. For each particle, this angle is randomly selected between 'Start Angle' and 'Start Angle 2'.
Loop	When checked, the particle system emits infinitely. Otherwise, it stops after emitting the number of particles specified by the 'Particle Count' property.
Pre Warm	When enabled, the particle system initializes as if it has completed a full cycle. This option can only be used with looping particle systems.
Lighting	When checked, particles are lit by directional and ambient lighting in the scene. In some cases, it may be beneficial to set a normal map on the particle system for more realistic lighting.
Half-Lambert	Enabling half-Lambert lighting prevents particles from appearing too flat when lit from behind. This is a completely non-physical lighting model but can provide more pleasing visual results. This option is only available when lighting is enabled.
Intensity	Scales the particle's color to allow for arbitrary brightness.
Depth Write	When checked, particles write depth information to the depth buffer. When unchecked, the depth buffer is not modified and particles overwrite each other based on rendering order.
Depth Softening	This variable value determines how much particles fade out as they get closer to other surfaces. This prevents situations where particles appear to cut through surfaces. Setting this value to 0 effectively disables depth softening. Setting a value greater than 0 requires the scene to be rendered to a depth target to perform depth comparison, which can have significant performance impact by increasing the total number of draw calls submitted each frame.
Sorting Mode	The sorting mode controls the order in which particles are rendered. Options are: None: Particles are rendered in arbitrary order. Selecting this option causes the particle system to be simulated on the GPU (if the underlying hardware supports floating-point textures). It is recommended to use this setting for best performance. Camera Distance: Particles are sorted on the CPU and rendered back-to-front (based on camera z-depth). Newer First: Particles are sorted on the CPU and rendered in age order, starting with the youngest. Older First: Particles are sorted on the CPU and rendered in age order, starting with the oldest.
Blending Mode	The blending mode determines how particles are composited when written to the frame buffer. Assuming Prgb is the particle pixel's RGB color, Pa is the alpha value, and Drgb is the RGB color already in the frame buffer, the blending options are: Additive: Prgb + Drgb Alpha: Prgb x Pa + Drgb x (1 - Pa) Multiply: Prgb * Drgb
Stretch	A world unit value that controls how much particles stretch based on their velocity. Particles stretch from their center toward their previous position.
Align To Motion	Aligns particles to their direction of motion.
Emitter Shape	The shape of the emitter.
Emitter Extents	The half-extents of the local space bounding box where particles are created at random positions.
Inner Extents	The exception volume of the local space bounding box where particles are not created.
Emitter Radius	The radius where particles are created at random positions.
Inner Radius	The inner sphere radius where particles are not created.
Wrap	Enables wrapping boundaries.
Local Space	Binds particles to the emitter node transform.
Screen Space	Renders particles in 2D screen space. Should be set when the particle system is part of a hierarchy with a ScreenComponent at the root, allowing the particle system to integrate with ElementComponent rendering.
Layers	The layers this particle system belongs to. If a particle system belongs to multiple layers, it will be rendered multiple times.
Wrap Bounds	A world space AABB volume centered on the owner entity's position. When particles cross one boundary of the volume, they teleport to the opposite side. You can move the owner entity of a wrapped emitter to create environmental effects like rain.
Orientation	The orientation mode controls the direction of the particle plane. Options are: Screen: Particles face the camera. World Normal: Defines a world space normal for the user to set the plane direction. Emitter Normal: Similar to the previous but the normal is affected by the emitter (entity) transform.
Particle Normal	The world or emitter space vector that defines the particle plane direction.
Color Map	The color map texture applied to all particles in the system. If no texture asset is assigned, a default spot texture is used.
Normal Map	The normal map texture applied to all particles in the system. Applying a normal map can make billboard particles appear more consistent with the scene's lighting.
Model Asset	The model asset. The first mesh found in the model is used to represent all particles instead of flat billboards.
Render Asset	A render asset that can be used instead of a model asset for rendering mesh-based particles.
Local Velocity	A curve that defines how each particle's velocity relative to the particle system's local coordinate system changes over time. If two curves are specified in the curve editor, local velocity becomes a random interpolation between the two curves.
Velocity	A curve that defines how each particle's velocity relative to the world coordinate system changes over time. If two curves are specified in the curve editor, velocity becomes a random interpolation between the two curves.
Radial Speed	A curve that defines how the particle's radial speed changes over time. Individual particle radial speed points from the emitter origin to the particle's current position. If two curves are specified in the curve editor, the value becomes a random value between the two curves.
Rotation Speed	A curve that defines how each particle's angular velocity changes over time. If two curves are specified in the curve editor, angular velocity becomes a random interpolation between the two curves.
Scale	A curve that defines how each particle's scale changes over time. By default, particles have a width and height of 1 unit. If two curves are specified in the curve editor, scale becomes a random interpolation between the two curves.
Color	A curve that defines how each particle's color changes over time.
Opacity	A curve that defines how each particle's opacity changes over time. If two curves are specified in the curve editor, opacity becomes a random interpolation between the two curves.

Scripting Interface

You can control the particle system component's properties using a script component. The particle system component's scripting interface is here.