I can see I'm not the first one to ask this, but I haven't seen a good answer anywhere.

I've got a vellum setup with multiple colliders and need to track particle age off collision with one particular collider. But none of the collision attributes seem to update. Hitnum remains at 0 regardless of collisions.

I've tried both SOP solver and DOPs, and both seem to be the same.

Anyone found a way around this?

Aside from the more immediate question, is there also a way to record which object collided so I can chart time based off that collision? Is there no hitpath in vellum?

Adding a POP collision detect node to the Sources pipe in either SOPs or DOPs works.

I couldn't get a good result doing this. It only worked for me if it was hitting a ground plane, but any other polygonal collider didn't work for me.