4.5 KiB
4.5 KiB
A particles generator in rust for laser shows
Philosophy
This library should allow users to define their own particle behaviours
- how many particles at start? min/max at any time? how many to add at any time?
- how do particles behave? Are there different types? Different shapes?
- how do particles react with real world? To audio? To a controller?
Constraints
- Render as lists of points in the form [x,y,color] with color encoded as 12 bits (r,g,b)
- i.e. it doesn't speak to the laser directly, we use a middleware for that part (see. xxx)
- it can output to STDOUT or send to redis
- Obviously be as fast as possible
- Use a physics engine as a tool for collision detection, velocity and more
- Be easy to use: good defaults for everything
- Handle bounding and drawing boxes
- Handle user custom particle properties (ex: decay, frequency, personality, etc.)
- Handle additional drawings for the current frame due to custom events (ex: random edge between two particles)
Questions
Working with the Physics engine
- Q: how do we enable custom behaviours (ex: reacting to audio)
- Q: how do we map physics engine object (ex: ball, square) for users as concept
- Q: how do we convert the physics engine objets to 2D points
- Q: how do we handle 3D? On by default?
How to use in a project
- Clone lj_rust_template and edit draw.rs
- add lj_particle library crate
- edit the draw function
- compile
Fundamental Features
- Use a 3D physics engine
- Provide hooks to create and update the simulation (onInit, onTick, onCollide, etc.)
- Render using box clipping for out of bound particles points
- Use an out-of-simulation list of additional points
- Render to STDOUT or Redis
Future Features
- Use a 2D physics engine
- Use attractors/repulsors objects
- Use OSC to update configuration
Library struct/objects
Particle
- PhysicsBody
- Shape : Square, Triangle, Circle, 3DSphere
- UserData // custom ex: life decay, seed, created_at, frequency
- Group
PhysicsEngine
PhysicsEngineConfig
RenderEngine
RenderEngineConfig
Config
- ParticlesGroups: vec<<Particle>
- RedisConfig
- PhysicsEngineConfig
- RenderEngineConfig
// future feature
OSCConfig
- OSCCache
- OSCServer <IP,Port>
API example
/***
An idea of the crate API
***/
use LJParticleSystem as ParticleSystem;
use LJRedilysis as Redilysis;
use Rapier as PhysicsEngine;
// Configure
let boundingbox = BoundingBox();
let clipping_box = ClippingBox();
let particle_system = ParticleSystem( ParticleSystemConfig, PhysicsEngine, ClippingBox, BoundingBox );
let redilysis = Redilysis ( RedilysisConfig( file_path ) );
// by default, equiprobability to generate a particle from any group
particle_system.new_particle( lambda() => { ... })
// some way to init the particles
world.init();
particle_system.tick = lambda(){
// Configuration update if read via OSC
current_config = self->getConfig();
// Retrieve bandwidth/bpm/rms info (with caching)
analysis = redilysis.update();
// Manage
self.boundingBox();
self.physicsEngine();
for( particle in self.getParticles() ) {
}
n_particles = current_config.particles_amount;
return self.clippingBox();
}
pub fn draw() -> Result<Vec<Point>, Box<dyn std::error::Error>> {
let mut v: Vec<Point> = vec![];
v.push( particle_system.tick() );
Ok(v)
}
OSC CONFIG
Actors and notations
- [S] Server / (LJ) OSC Server and client
eventual config
channel 1 : IP
channel X : IP
- [R] Rust = (LJ Particle) OSC Server and Client
- [U] User Interface = (Tablet) HTML Interface
- [c] Program Channel = configurable, uint ex: 1
- [n] Programe name = configurable, string ex: particle_foo_square
Sequence Diagram
# Prerequisite : [S] is running and available and U is connected to [S]
# [R] starts
# [R]: Do you have my config already ?
[R] -> [S] "/program/${c}/${n}/configure"
# [S] needs to stock which program is currently used for ${n} channel and its parameters
# If no, [S] manifests the need to init the configuration
[S] -> [R] "/program/${c}/${n}/no-config"
# If no-config, [R] sends its default config for [S] to store
[R] -> [S] "/program/${c}/${n}/var1 default_value1" # etc.
# In any case, [S] sends to [R] the current config
[S] -> [R] "/program/${c}/${n}/var1 value1" # etc.
# [S] creates an event for the User to change
[S] -> U "/program/${c}/${n}"
# U can change the program configuration
U -> [S] "/program/${c}/${n}"