Crate berdicles

berdicles

Expressive CPU particle system for the bevy engine.

Feature Set

• Instancing based CPU particles.
• Expressive trait based particles.
• Particles as emitters.
• Particles trails.
• Particle events.
• Billboard particles.

Non-features

• GPU simulation.
• SIMD and similar optimizations.

Basically the crates trades some potential optimizations for expressiveness.

Getting Started

Add a ParticleSystemBundle, which is a MaterialMeshBundle with a ParticleInstance.

• Huh?

First we need to add ParticleMaterialPlugin, not MaterialPlugin, which sets up a different render pipeline. This uses the mesh as the particle shape and the shader for instancing. The StandardParticle is already setup in this crate, but you can define your own Material by referencing this shader’s source code.

To create a ParticleInstance we need a ParticleSystem trait implementor and a Particle that it spawns.

Sub-particle Systems

SubParticleSystem uses a parent particle system’s particles as spawners.

• Add ParticleParent(Entity) to point to a parent
• Add the downcast function as_sub_particle_system to your ParticleSystem implementation.

Yes you can chain these infinitely.

Event Particle Systems

EventParticleSystem can listen to events like particle despawning or colliding and spawn particles on events.

• Add ParticleParent(Entity) to point to a parent
• Add ParticleEventBuffer to the parent to record these events,
• Add the downcast function as_event_particle_system to your ParticleSystem implementation.

Trail Rendering

We can render trails behind particles as mesh.

• Implement TrailedParticle on your particle.
• Add on_update, detach_slice and as_trail_particle_system to your ParticleSystem implementation.
• Add TrailMeshOf(Entity) to a MaterialMeshBundle to render them.

Versions

bevy	berdicles
0.14	latest

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Modules

• shader
  Shader module for berdicles.
• trail
  Module for rendering trails.
• util
  Utility for implementing particles.

Structs

• BillboardCamera
  Marker component that selects Camera for billboard rendering.
• BillboardParticle
  Add to a ParticleSystemBundle to make it always face the camera.
• DebugParticle
  Material that displays useful debug info of a particle.
• ExtractedParticle
  Instance buffer of a particle.
• ParticleBuffer
  Type erased buffer for particles.
• ParticleEvent
  Event and data on an individual particle.
• ParticleEventBuffer
  A buffer of particle events. If added to a particle bundle, will record particle events happened in this frame. Also enables EventParticleSystem.
• ParticleInstance
  Component form of a type erased ParticleSystem.
• ParticleMaterialPlugin
  Add particle rendering pipeline for a Material.
• ParticleParent
  Parent of the particle, if present will read data/event from the parent’s particle buffer.
• ParticlePlugin
  Plugin for berdicle.
• ParticleSystemBundle
  A Bundle of a particle system.
• RingBuffer
  A domain specific data structure for implementing TrailBuffer.
• StandardParticle
  Material that displays an unlit combination of base_color and texture on a mesh.

Enums

• ExpirationState
  If and how a particle has expired.
• ParticleBufferStrategy
  Strategy for cleaning up particle buffers.
• ParticleBufferType
  Type of particle buffer.
• ParticleEventType
  Event on individual particle.

Traits

• ErasedEventParticleSystem
  Type erased EventParticleSystem.
• ErasedParticleSystem
  Type erased version of ParticleSystem.
• ErasedSubParticleSystem
  An erased SubParticleSystem.
• EventParticleSystem
  A ParticleSystem that spawns particles on parent’s emitted events.
• Particle
  A Particle. Must be Copy and have alignment less than 16.
• ParticleSystem
  A particle spawner type.
• SubParticleSystem
  A ParticleSystem that spawns particles from a parent ParticleSystem’s alive particles.

Functions

• billboard_system
  System for calculating billboard orientation.
• particle_system
  The main system of berdicle, runs in Update.