What's a good method for preserving particleIDs?

As particles die, Houdini reassigns the IDs, right?

I need to preserve the particleIDs so I can calculate acceleration for multi-step particle motion blur. For this to work, the IDs need to stay consistent and not be reused.

I've tried a combination of the Trail SOP and a SOPSolver looking up the previous frame ID to carry it forward, but once the particles start dying this falls apart.

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mC

Try turning off particle reaping.
You can always delete by age, later, after the popnet.

MoltenCrazy
As particles die, Houdini reassigns the IDs, right?

the i@id attribute created by most of the solver is unique and as particle dies the id is not reused so you should be able to use Trail with Match By (id) Attribute , or idtopoint() VEX function to lookup points by value of id attribute