Hi,
I'm doing particle instance simple crowd. I have randomly rotated/positioned static particles. A box slides over and adds collided particles into a “hit_group”, while other particles are in a “nohit_group”.

I noticed in SOP, instancing uses Normal and upvector, while POP instance uses velocity and upvector, correct?
In SOP I defined N and up correctly, and the rotation works for SOP instancing.
But in POP, how do I give instancePOP the orientation without the particle flying away.
Or is it possible to convert N & up axes into “fixed axes” in instancePOP?

Things I tried:
source->animated grouping-> attribute v=$N -> instance -> attribute v=0
Instance rotates to correct angle, but with last attributePOP activated to reset v, it affects upstream instancePOP and rotation reverts to zero. Shouldn't nodes only affect downstream? Same if I try velocityPOP.

suppressPOP, suppress velocity=1, doesn't work. suppress position=1, keeps position while velocity gives correct rotation, but suppressPOP somehow deactivates animated groupPOPs way upstream.
Also tried turning suppress on and off along the POP connections, but order really doesn't matter it seams. Only the last suppress in the connections matter.

Same issue with statePOP, stopped=1.

I know suppressPOP affects pstate, but it doesn't make $DEAD=1, and even so group SOPs should still work.