Wojciech Portnicki

Hi all, a Houdini newbie here

I'm trying to create a simulation where water droplets are being born on a surface of a glass.
when they reach a certain size (pscale) I want a downward force to affect them (making them slide down).

I figured out I could make a pop group and use a pop force to affect only that group.
The group I've made has this rule:

ingroup = f@pscale > 1;

And my particles are growing from 0 to 2 (pscale) within a 5s time range.

But it doesn't work. If I use ‘age’ instead (or the default “every 5th particle”) it does work.
But that's not really what I want, but proves the rest of my setup is fine.

So I'm thinking that maybe pscale is not a valid attribute for a particles? as particle is only a point in space and pscale adresses the particles representation (I'm using a sphere copied via copy-to-points)?

I've made a simplified version of my scene with 2 particle groups (based on pscale and on age) and a force that's restricted to work only on either of these groups. The one with ‘age’ paramiter works fine, the one with pscale doesn't.

I've searched the forum for a similar question but couldn't find an answer, so I'm sorry if this has been answered already