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

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.

Cheers,

Peter B

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?

You know what. I've been using Houdini for years and yesterday I realized some important things about collision that I wasn't aware of. I think the collision needs to be improve and more example files with different collision case.

As soon as I finish figuring all this out I'm going to ask Side FX to do something about it.

Don't give up. Houdini is fun in the end.

François