kmannens

It's been a while but I believe the Creep sets a new State (i.e. “creeping”) that overrides normal collision and forces. I think you need to release the particles (via the State POP? not sure) for them to “carry on” being normal particles that can collide.

Indeed, when I add a state POP and set “sliding” to 0, the collide POP works.

Thanks for the help, Peter.

Being new to Houdini, I must say that obscure behavior like the one exemplified above makes learning Houdini frustrating and above all time consuming at times. If it was for Peter's help, I would have never figured that out. The docs for the creep POP state: “This operator affects the following attributes: pstate (uniform scale)” and SLIDING is indeed a standard POP variable, but how am I to know that the creep POP changes the SLIDING state?

Is there any reason why collision POP would stop working when used downstream from a creep POP?

The main control over this is in the “state”

Works like a charm. Thanks!