AdvancedOptionalaEnd-of-life opacity, with alphaEnd
OptionalaBirth time on the system clock
OptionalaEnd-of-life tint in display (sRGB) space, each component 0 to 1, with colorEnd
OptionalaLifetime in seconds
OptionalaEnd-of-life size, with sizeEnd
OptionalaRotation rate in radians per second, with spin
OptionalaLaunch velocity, in units per second
The system's own attributes, which setParticle takes on top of the container's
aVel,aBirthandaLifeare always there. The rest exist only on a system built with their option; on any other,setParticlethrows on them. spawn takes most of them under their option names instead, such assizeEndforaSizeEnd.