can someone explain me what the preserve group toggles does??
i am watching the technical fx tutorials from 3d buzz and i kind of understand what is doing in this context , but not in a general level…
so if someone could debrief it to me , would be gr8…
thank you.

HI, what I understood is this

Particle can be a member of a group if it satisfies certain condition / s. There could be two situations

1) Particle always satisfy the condition so it will always be a member of that group.

2) Particle satisfies the condition for some period and not for the rest of the period.

In this case if PRESERVE GROUP is turned on then HOUDINI will always remember the particle which has ever satisfied the condition, meaning once you become member of the group you will always be a member of that group even if you are not satisfing the condition necessary to be a member of that group.

If PRESERVE GROUP is turned off then HOUDINI will check the condition necessary to be the member of the group on every calculation step (which it does even when PRESERVE GROUP is turned on ) and only those particles which are satisfing the condition at that specific timestep will be the members of that group.

your answer is Nice and clear.
thank you.