Particle System Reference

File:Titans-icon.png Planetary Annihilation Titans & Classic Particle Effect System Reference

Work in progress, go here.

Overview of how the system works: (mental notes) Each effect, (called a particle system), is defined as a list of particle emitters. Each emitter can control things like the color, velocity, drag, and lifetime of the particles they spawn. Emitter is an entity that spawns particles over time. Properties that you define for your emitter either apply directly to the way the emitter produces particles, or they apply to the particles that are spawned. You can think of this as the emitter defining various properties over time, and then the moment a particle is spawned, it inherits a snapshot of those values.

Glossary

// Particle System
{
    "emitters": [{
        "spec" : {<particle properties>},
        <emitter properties>
    }],
    "color": <global color multiplier>
}

Particle System

The group of particle emitters.

Field Name	Field Type (default value) - Description
emitters	array ( [] ) The list of emitter objects in the system.
color	color ( [1.0, 1.0, 1.0, 1.0] ) A system wide color multiplier. Value is RGBA linear float color values in a JSON array.

Emitter System

Defines the position and movement behavior of particles.

Field Name	Field Type (default value) - Description
spec	object ( ) The particle spec definition.
type	string ( "POSITION" ) Defines the shape of the particle spawn positions, and how the offset* keys are interpreted. Valid types are "POSITION", "SPHEROID", "SHELL", "EMITTER", "CYLINDER_X", "CYLINDER_Y", and "CYLINDER_Z"
linkIndex	number ( -1.0 ) Used when the type is set to "EMITTER" to define the emitter to attach to.
offsetX offsetY offsetZ	emitter time curve ( 0.0 ) Define the starting spawn position for the particles in emitter space. The shape of the emitter space depends on the type field.
offsetRangetX offsetRangetY offsetRangetZ	emitter time curve ( 0.0 ) Define the starting spawn position range in which a particle can randomly deviate from offsetX, offsetY, and offsetZ.
offsetAllowNegZ	bool ( true ) Allow particles to spawn with an initial positiong with a negative Z in emitter space, otherwise flip Z to a positive position. Useful for explosions on the ground so that particles travel only up.
velocityX velocityY velocityZ	emitter time curve ( 0.0 ) Initial velocity direction in emitter space. This is for indicating direction only, so if you increase any of these the actual speed of the particle will not change, only the direction.
velocityRangeX velocityRangeY velocityRangeZ	emitter time curve ( 0.0 ) Initial velocity direction range in which a particle can randomly deviate from velocityX, velocityY, and velocityZ.
useRadialVelocityDir	bool ( false ) Use the starting location as a normalized vector in addition to the velocity direction values.
useShapeVelocityDir	bool ( false ) Use the starting position on the shape from the emitter's type in addition to the velocity direction values.
velocity	emitter time curve ( 1.0 ) Initial particle velocity along velocity direction vector at spawn.