Particles

With a particle system you can use sprites, 3D models, or images to create effects that are hard to reproduce with conventional rendering techniques. This includes chaotic systems, natural phenomena, or processes caused by chemical reactions. For example, you can simulate fire, smoke, sparks, explosions, flowing water, fog, snow, stars, and galaxies.

The Qt Design Studio particle system contains the following main types of components:

Preset particle components, templates, and effects are available in Components > QtQuick3D Particles3D after you add the QtQuick3D.Particles3D module to your project, as instructed in Adding and Removing Modules.

"3D Particles"

Particle Components

When you add an instance of the Particle System component to a scene, Qt Design Studio automatically adds instances of the Sprite Particle, Emitter, and Vector Direction components for you.

"Particle System in Navigator"

The Sprite Particle is a visual 2D texture particle. To use 3D model particles, add instances of the Model Particle component to the particle system. It is important to define the amount of particles to use in Properties > Particle > Max amount, so that the optimal buffer sizes get allocated. You can also specify the color and opacity of the particles, as well as the speed at which they fade in and out.

The Emitter component emits the sprite or model particles. You can specify particle shape and the area where they are emitted. Use variation in particle size and rotation for more natural results. Further, define the life span and initial direction of speed of the emitted particles.

Usually, affectors are used to make particle movement more interesting. For example, you could add an instance of the Gravity component to simulate falling objects, an instance of the Wander component to simulate flying objects that follow wavy curves, or an instance of the Point Rotator to simulate windy weather.

The following table lists preset particle components.

IconNamePurpose
AttractorAttracts particles towards a specific point.
Emit BurstGenerates declarative emitter bursts.
EmitterEmits logical particles.
GravityAccelerates particles to a vector of the specified magnitude in the specified direction.
Model Blend ParticleBlends a particle effect with an instance of a Model component.
Model ParticleCreates a particle that uses an instance of a Model component.
Model ShapeProvides 3D shapes from a model to emitters and affectors.
Particle ShapeProvides 3D shapes to emitters and affectors.
Particle SystemCreates a particle system that includes particle, emitter, and affector components.
Point RotatorRotates particles around a pivot point.
Sprite ParticleCreates particles that use a 2D sprite texture.
Sprite SequenceProvides image sequence features for Sprite Particle component instances.
Target DirectionSpecifies a direction towards the target position.
Trail EmitterEmits logical particles from other particles.
Vector DirectionSpecifies a direction towards the target direction.
WanderApplies random wave curves to particles.

Particle Templates

A particle template is a preset of particle components that you can use to create specific particle effects in a convenient way.

The following table lists particle templates and their components.

TemplateComponents
Animated SpriteParticle System
  • Particle Emitter
    • Sprite Particle
    • Sprite Sequence
    • Texture
  • Vector Direction
AttractorParticle System
  • Particle Emitter
    • Sprite Particle
    • Vector Direction
  • Particle Attractor
BurstParticle System
  • Particle Emitter
    • Sprite Particle
    • Vector Direction
    • Emit Burst
Model BlendParticle System
  • Particle Emitter
    • Node
    • Model Blend Particle
    • Particle Emitter
      • Vector Direction
Model ShapeParticle System
  • Particle Emitter
    • Sprite Particle
      • Vector Direction
  • Particle Model Shape
Particle TrailParticle System
  • Trail Emitter
    • Vector Direction
    • Sprite Particle
  • Particle Emitter
    • Vector Direction
    • Sprite Particle
SpriteParticle System
  • Sprite Emitter
    • Sprite Particle
    • Vector Direction
WanderParticle System
  • Sprite Emitter
    • Sprite Particle
      • Texture
    • Wander
    • Node

Particle Effects

A particle effect is a ready-made effect that you can use to create, for example, fire, rain, or mist in a convenient way.

The following particle effects are available:

  • Clouds
  • Dust
  • Exhaust
  • Fire
  • Heavy Rain
  • Heavy Tire Spray
  • Light Rain
  • Light Tire Spray
  • Rain Mist
  • Snow
  • Steam

Adding a Particle System

The recommended way to add a particle system is to use one of the particle templates and then add or remove particle components according to your use case.

For example, to add a particle system that emits sprite particles:

  • From Qt Quick 3D Particles System Templates in Components, drag Sprite to a scene component in Navigator. You can also drag it to the 3D view.

Performance Considerations

The particles are designed to be usable on a variety of hardware on desktops, as well as mobile and embedded devices. However, in addition to rendering the maximum amount of particle elements on the screen, extensibility to different use-cases, rendering quality, integration with the other UI elements, are also important.

Currently, the rendering runs on GPU, while the particle system logic runs on CPU. However, the stateless particle system enables you to move the system logic onto GPU if that seems beneficial. The initial measurements indicate that the system is quite well balanced between CPU and GPU. The stateless system also enables animating particles by using a timeline. The model particles use instanced rendering to boost the performance. Therefore, OpenGL ES 2.0 isn't sufficient to make rendering performant, and at least OpenGL ES 3.0, Vulkan, or some other modern backend is required.

To get a more concrete view on the actual performance, the video below shows a particles Testbed application running on four different Android devices. These devices and their chipsets and GPUs could be considered to be lower-end to mid-range, confirming that the particles can perform well also on affordable hardware.

Particle System Tutorials

Available under certain Qt licenses.
Find out more.