Particle Types

The particle type defines how particles move through space (e.g. velocity, acceleration) and how they look (e.g. size, color). Each particle emitter has a list of assigned particle types, which it will use for generating particles.

In the object browser, particle types are shown below the list of nodes. You can assign a particle type to a particle emitter by dragging and dropping it on the particle emitter in the node list:

Particle sub-types

To create complex effects it is often necessary for particles to be spawned after one another, for example a smoke particle created from a fire particle. In the object browser, drag & drop a particle type onto another particle type to make it a sub-type of the latter. This way, particles of the sub-type are generated at the positions of particles of the parent particle type. Note that the Primary property of sub-type’s emitter needs to be disabled.

Particle renderers

There are three types of particles, which determines how they are rendered in the scene. Each renderer has some additional options.

Sprite particle

The sprite renderer renders each particle as a separate sprite/quad.

Sort criterion

How particles are sorted for rendering. For correct sorting when using alpha-blending, particles need to be sorted back-to-front by selecting Distance.

Trail particle

The trail renderer generates continuous trails along the path of particles with the same parent particle.

Texture mode

How the texture is applied to the trail.

• Stretch: The texture is stretched along the entire length of the trail.

• Tile: The texture repeats if the trail becomes longer than one world unit.

• Repeat per segment: The texture repeats for every particle.

UV rotation

Orientation of the texture on the trail.

UV factor

Can be used to scale and repeat the texture on the trail.

Smooth

Generates a smooth curve with a specified number of segments along the path of particles if enabled. If disabled, each particle generates a new trail segments.

Segments

Number of generated segments if Smooth is enabled.

Mesh particle

The mesh renderer renders each particles as a 3D mesh.

Mesh

Which mesh is used to render particles.

Sort criterion

How particles are sorted for rendering. For correct sorting when using alpha-blending, particles need to be sorted back-to-front by selecting Distance.

Properties

The following properties can be adjusted in the property window to influence the look and behavior of the particles.

General

Property	Description
Lifespan	How long particles exist after being spawned by their emitter.
Lifespan variance	How much the lifespan varies between particles.
Number	How many particles of this type are spawned by the emitter.
Position	Motion path of particles, shown in the scene view if the property is selected.
Motion path force	How much particles are influenced by the motion path. Set to 0 to disable motion paths.
Simulation space	Whether the particle simulation is performed in global space or local space. In local space, particles follow their parent emitter.
LOD Strategy	How particles behave at different levels of detail.

Visual

Property	Description
Material	Material that particles use for rendering. The parameters of the active material can be accessed with . See particle materials for details.
Renderer	Renderer used to generate the particle geometry. Click to show additional options for each renderer.
Layer	Layer on which particles are drawn. Particles on upper layers occlude those on lower layers.
Color	Color of particles over their lifetime. Double-click or right-click the color gradient to add another color. Double-clicking a color marker lets you choose its color, right-clicking removes it. To change the position of color markers, drag them around using the mouse.
Color variance	How much the color varies between particles.
Initial opacity	Opacity of each particle when created.
Opacity	Opacity of each particle over its lifetime as a fraction of its initial opacity.
Opacity variance	How much the opacity varies between particles.
Initial size	Size of each particle when created.
Size	Size of each particle over its lifetime as a fraction of its initial size.
Size variance	How much the size varies between particles.
Stretch	How much particles are stretched based on their speed.

Motion

Property	Description
Initial velocity	How fast each particle is initially after being spawned by the emitter.
Inherited velocity	How much speed particles inherit from the parent particle or emitter.
Velocity variance	How much the speed varies between particles.
Acceleration	Linear acceleration applied to each particle over its lifetime. Positive values speed up particles, while negative values slow them down.
Radial acceleration	Acceleration of each particle towards the emitter over its lifetime. If you select negative values here, particles are repelled from the emitter.
Alignment mode	The direction to which particles are aligned: None: Particles do not align to anything. Camera: Particles always face the camera (3D). Motion: Particles align to their own velocity vector. Emission direction: Particles face their emitter. Emitter: Particles copy the rotation of their emitter.
Rotation mode	Whether the rotation property represents the exact rotation of particles or their angular velocity.
Initial rotation	Rotation of each particle when created, in degrees. For 3D effects, rotation is composed of roll, yaw and pitch.
Rotation	How particles rotate over time from their initial rotation.
Rotation variance	How much the rotation varies between particles.
Angular velocity variance	How much the angular velocity varies between particles.
Rotation by speed	How much particles rotate based on their velocity.
Pivot	Center of rotation, relative to the particle’s center.

Physics

Property	Description
Physical size	The relative size of particles for motion and collision calculations.
Weight	How strongly particles are affected by force fields.
Bounce	How strongly particles bounce off colliders after collisions.
Friction	How resistant particles are to sliding down colliders.