Hey, i have a scene with water trails forming which are led by a particle stream named “leads”, these in turn replicate into “trails” with an attribute to which lead they came from.

What i would like to have is that the trails should merge when a lead particle comes close enough to another trail, with a small force, to stick it into place.

My setup is to have a popvop where i read in the points through a “point cloud open”, and the first (minor) problem is that i would like to filter the point cloud so that i only get the trails, and not the leads.
The bigger issue is that when i actually find the points in the point cloud that the leads are close to, it's in most cases it's own trail, so for the point cloud, i would like to filter away the points that have the attribute that points to the current lead.

Are there a better way to solve this? i'm all ears
And, for educational purposes, is there a way to filter the point cloud this way before attracting the lead to the trails?

I've not looked at your file, but you might be able to group your particles by attribute, and then apply the popvop just to the group that you want. Alternatively you can check attributes as you loop through the points using an if vop.

So for that i would have to create multiple groups? right? since for every point in the leads group that i loop through, the group needs to be different, for every point, i want to get all other points trails, so all trails BUT the one point i am currently processing..

I was thinking about the looping as well, but i couldn't really figure it out, since in my “point cloud open” node, if i tell it to get 10 points, after this i filter away the points that belong to the “own” trail, and that operation might filter away all the points i fetched from the point cloud open node.
I guess i could remove the count limit, and only fetch points based on proximity, filter away the ones that belong to the correct trails, and then cap to the amount i want, but it doesn't really smell right.
Or maybe I'm just thinking about this all wrong

I would be really interested in how this could be done with point clouds, but for this task i had, since it was in a bit of a hurry, i solved it all through a sop solver instead, which worked all fine.

Most of my Houdini knowledge come from your Vimeo tutorials btw..
Thanks a bunch for all of that fabulous information you put out there.
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