Hello,
For studying pop I build a simple pop point cloud with a subnet and a pop merge to be able to access the points.
This part is working but as you can see on my file, when the particles begin to fall (based on their density), the new ones continue to fall because they are refering to the subnet which is not updated after the vop pop in the popnet.

Is there a workaround to make the density to be computed with the real state of the particles and not the one in the pop merge? (density is not the deal here, it's more to learn about pop point clouds).

Thanks,
Arthur

Because your pop merge pulls out particles always from Source POP. So they are just created and that's all.
It is not like you takes the state of the particles from previous frame, add only source POP from current frame and pop merge all these particles and use as pointcloud.

The problem with pops is that they are special kind of primitive and can't be used directly as points (and as pointcloud). So you can bring them to DOPS (or use Solver SOP which internally is dopnet) where they are internally converted to points and use these points from previous iteration as pointcloud.

Thanks for your explanations bloomendale!

Here is the working pop point cloud for those who may have the same issues.