Particles

Inherits: GeometryInstance < VisualInstance < CullInstance < Spatial < Node < Object

GPU-based 3D particle emitter.

Description

3D particle node used to create a variety of particle systems and effects. Particles features an emitter that generates some number of particles at a given rate.

Use the process_material property to add a ParticlesMaterial to configure particle appearance and behavior. Alternatively, you can add a ShaderMaterial which will be applied to all particles.

Note: Particles only work when using the GLES3 renderer. If using the GLES2 renderer, use CPUParticles instead. You can convert Particles to CPUParticles by selecting the node, clicking the Particles menu at the top of the 3D editor viewport then choosing Convert to CPUParticles.

Note: On macOS, Particles rendering is much slower than CPUParticles due to transform feedback being implemented on the CPU instead of the GPU. Consider using CPUParticles instead when targeting macOS.

Note: After working on a Particles node, remember to update its visibility_aabb by selecting it, clicking the Particles menu at the top of the 3D editor viewport then choose Generate Visibility AABB. Otherwise, particles may suddenly disappear depending on the camera position and angle.

Tutorials

Properties

int

amount

8

DrawOrder

draw_order

0

Mesh

draw_pass_1

Mesh

draw_pass_2

Mesh

draw_pass_3

Mesh

draw_pass_4

int

draw_passes

1

bool

emitting

true

float

explosiveness

0.0

int

fixed_fps

0

bool

fract_delta

true

float

lifetime

1.0

bool

local_coords

true

bool

one_shot

false

float

preprocess

0.0

Material

process_material

float

randomness

0.0

float

speed_scale

1.0

AABB

visibility_aabb

AABB( -4, -4, -4, 8, 8, 8 )

Methods

AABB

capture_aabb ( ) const

Mesh

get_draw_pass_mesh ( int pass ) const

void

restart ( )

void

set_draw_pass_mesh ( int pass, Mesh mesh )

Signals

finished ( )

Emitted when all active particles have finished processing. When one_shot is disabled, particles will process continuously, so this is never emitted.

Note: Due to the particles being computed on the GPU there might be a delay before the signal gets emitted.

Enumerations

enum DrawOrder:

DrawOrder DRAW_ORDER_INDEX = 0

Particles are drawn in the order emitted.

DrawOrder DRAW_ORDER_LIFETIME = 1

Particles are drawn in order of remaining lifetime.

DrawOrder DRAW_ORDER_VIEW_DEPTH = 2

Particles are drawn in order of depth.

Constants

MAX_DRAW_PASSES = 4

Maximum number of draw passes supported.

Property Descriptions

int amount = 8

  • void set_amount ( int value )

  • int get_amount ( )

The number of particles emitted in one emission cycle (corresponding to the lifetime).

Note: Changing amount will reset the particle emission, therefore removing all particles that were already emitted before changing amount.

DrawOrder draw_order = 0

Particle draw order. Uses DrawOrder values.

Mesh draw_pass_1

  • void set_draw_pass_mesh ( int pass, Mesh mesh )

  • Mesh get_draw_pass_mesh ( int pass ) const

Mesh that is drawn for the first draw pass.

Mesh draw_pass_2

  • void set_draw_pass_mesh ( int pass, Mesh mesh )

  • Mesh get_draw_pass_mesh ( int pass ) const

Mesh that is drawn for the second draw pass.

Mesh draw_pass_3

  • void set_draw_pass_mesh ( int pass, Mesh mesh )

  • Mesh get_draw_pass_mesh ( int pass ) const

Mesh that is drawn for the third draw pass.

Mesh draw_pass_4

  • void set_draw_pass_mesh ( int pass, Mesh mesh )

  • Mesh get_draw_pass_mesh ( int pass ) const

Mesh that is drawn for the fourth draw pass.

int draw_passes = 1

  • void set_draw_passes ( int value )

  • int get_draw_passes ( )

The number of draw passes when rendering particles.

bool emitting = true

  • void set_emitting ( bool value )

  • bool is_emitting ( )

If true, particles are being emitted.

float explosiveness = 0.0

  • void set_explosiveness_ratio ( float value )

  • float get_explosiveness_ratio ( )

Time ratio between each emission. If 0, particles are emitted continuously. If 1, all particles are emitted simultaneously.

int fixed_fps = 0

  • void set_fixed_fps ( int value )

  • int get_fixed_fps ( )

The particle system's frame rate is fixed to a value. For instance, changing the value to 2 will make the particles render at 2 frames per second. Note this does not slow down the simulation of the particle system itself.

bool fract_delta = true

  • void set_fractional_delta ( bool value )

  • bool get_fractional_delta ( )

If true, results in fractional delta calculation which has a smoother particles display effect.

float lifetime = 1.0

  • void set_lifetime ( float value )

  • float get_lifetime ( )

The amount of time each particle will exist (in seconds).

bool local_coords = true

  • void set_use_local_coordinates ( bool value )

  • bool get_use_local_coordinates ( )

If true, particles use the parent node's coordinate space. If false, they use global coordinates.

bool one_shot = false

  • void set_one_shot ( bool value )

  • bool get_one_shot ( )

If true, only amount particles will be emitted.

float preprocess = 0.0

  • void set_pre_process_time ( float value )

  • float get_pre_process_time ( )

Amount of time to preprocess the particles before animation starts. Lets you start the animation some time after particles have started emitting.

Material process_material

  • void set_process_material ( Material value )

  • Material get_process_material ( )

Material for processing particles. Can be a ParticlesMaterial or a ShaderMaterial.

float randomness = 0.0

  • void set_randomness_ratio ( float value )

  • float get_randomness_ratio ( )

Emission randomness ratio.

float speed_scale = 1.0

  • void set_speed_scale ( float value )

  • float get_speed_scale ( )

Speed scaling ratio. A value of 0 can be used to pause the particles.

AABB visibility_aabb = AABB( -4, -4, -4, 8, 8, 8 )

  • void set_visibility_aabb ( AABB value )

  • AABB get_visibility_aabb ( )

The AABB that determines the node's region which needs to be visible on screen for the particle system to be active.

Grow the box if particles suddenly appear/disappear when the node enters/exits the screen. The AABB can be grown via code or with the Particles → Generate AABB editor tool.

Note: If the ParticlesMaterial in use is configured to cast shadows, you may want to enlarge this AABB to ensure the shadow is updated when particles are off-screen.

Method Descriptions

AABB capture_aabb ( ) const

Returns the axis-aligned bounding box that contains all the particles that are active in the current frame.

Mesh get_draw_pass_mesh ( int pass ) const

Returns the Mesh that is drawn at index pass.

void restart ( )

Restarts the particle emission, clearing existing particles.

void set_draw_pass_mesh ( int pass, Mesh mesh )

Sets the Mesh that is drawn at index pass.