Hi. I'm trying to do what seemed like a straightforward pin to animation in MPM, with the following settings on my animated MPM source:


But the solver just ignores it. The object stays pinned in place and does not follow the animation. This is in Houdini 21.0.440 on macOS 15.6.1.

I've attached an example hip file exhibiting this behavior. What am I doing wrong?

this is likely an oversight on MPM Source
since setting Emission Type to Once also freezes the animation that's then being sampled internally
so if you want to avoid unlocking the MPM Source or transferring animation yourself afterwards you can do:

- set Emission Type to: Continuous
- set Activation to: $FF==detail("CONTAINER", "startframe", 0)

Thank you, Tomas. This was a helpful workaround. I'll file a bug report to have the issue fixed.

- Joe