I'm interested in creating a particle effect where one particle gets ‘infected’ (goes red) and the infection spreads to it's neighbouring particles.

In the uploaded file any particle within a certain distance to another gets infected. And when it's infected it activated the Pop Interact which sucks other particles towards it. It's half way to what I want.

What I really want is if the two particles are within a certain distance AND one of the particles is infected they both get infected.

I'm scratching my head a bit because I'm not sure what process I'd use to do this. Any pointers on a direction would be appreciated but go easy because I'm still very much learning.

One idea, have an integer attribute that tells if a point is infected or not (i.e. i@infected = 0, then change that to 1 whenever they're infected.

Then, since POP Proximilty gives you the nearest point id (@nearest), you can look up the nearest point's infected status in a POP Wrangle (after the Proximity, but before the POP Group), with something like this:


@infected = point(0,“infected”,@nearest);


And adjust your POP Group's expression like this


ingroup = (@nearestdist < 0.01) * @infected ;


Hope that helps!