Channel-specific interfaces for ParticleChannelID.
The channel is used to identify particles. Particle ID consists of two integers: particleIndex and particleBorn. ParticleIndex gives relative correspondense to the whole amount of particles. If PF ParticleAmountMultiplier is set to 100% then the given particleIndex are successive ordinal numbers. If it's set to 50% then the given particle indeces are 0, 2, 4, 6 etc. If it is a Birth by Total Number then the last particle born has an index of the total number whatever multiplier is. ParticleBorn number always are successive ordinal numbers when particles were born: 0, 1, 2, 3 etc. If ParticleAmountMultiplier equals 100% then for a particular particle particleIndex and particleBorn are the same number. If ParticleAmountMultiplier is greater then 100% then you may have several particles with the same particleIndex. It is recommended to link non-random properties to particleIndex and random properties to particleBorn.