Hello everyone..

I have a really straightforward problem, but I don't know why my passive particles won't become active through VEX.

I tried it with a collision, and it seems like some velocity or interaction can activate the particles.

Is there any way to switch the passive particles to active in MPM without any interaction?

Thanks in advance!

any help ;( ?

Hello. I managed to find a workaround by doing the opposite of what feels intuitive and it solved the issue.
I noticed that MPM solver caches state changes on first frame and it constantly kept ignoring VEX conditions in passive state, both in SOPs and DOPs.
On MPM Source I initialized the particles as Active instead of Passive. On MPM Solver I disabled "Enable Auto Sleep". We ultimately want all particles to be simulated so we don't need it to interfere with states. In MPM Solver dive target, I forced particles to stay still until trigger condition is met by using VEXpression inside popdrag and popdragspin nodes. I also forced points to keep rest position as long as the condition is met.

I also appended a hip file. I hope it helps!

Thank you soo much for your HIP and explain...
but bigger scale which i have , i was looking more efficient to use sleeping which calculation was faster