Particle collision and gravity force group filter usage in Houdini 13?

[reny]

Hi everyone,

 

I have some simple and probably noobish questions here and eager to understand what actually happened.

Attached file is grouped into 4 different setup from most simple/dumb way, toward last which use POP Replicate with POP VOP.

The goal is simple, to make particle collide with box2(bounce) and gravity will not affect it afterward.

 

When use static solver, collision detect on both POP Solver and POP Collision Detect will not work, they still create those hit attributes but coloring and behavior will not act accordingly.

Disable static collision, then particle won't bounce, but both collision coloring and behavior worked.
I've used POPVOP in network 3 and 4 to set the velocity if hitnum is not zero to check if gravty force is actually filtered.

 

Disable gravity via particle group name never work in all of my attempt.

 

Now, I know you don't have to use gravity force, you can use a POP Force as replacement and POP VOP to calculate bounce velocity etc.

But I wanted to know why it works this way, so here are my questions:

1. if POP Solver's collision behavior tab can't detect static rbd collision, what's the point giving it to the solver?
2. document of pop nodes never explain clearly Stream/Bindings, I watched the H13 particle master class and have a bit understanding to stream, but bindings?
3. Gravity force, in the group slot, there is a tiny drop down button at right hand side, which shows available dop objects in this network, not particle groups. If that's the case, is there any way to make replicated particle belong to another POPobject? How do you set it up?
4. also, if all the particle group info clearly survived till the point of gravity force, why isn't "* ^hit" or "* ^stream_blahblah" working?

Thanks to many of the contributors here that answered my questions both in the past(Houdini 6 and 9) and recent(just pick up Houdini again starting 13).
I have to say I like Houdini 13 a lot, you can do crazy things with it, but you need to know the rules of its engine and where to get stuff you want, and "sometimes" it's not as straight forward as you expect it to be.

And, I need to rewatch that master class again tomorrow.

 

Cheers~

 

particleCollision.hipnc

[cgBurns]

Hey there Reny!

 

I wonder if you found a solution to this problem?

 

Update, I found a pretty neat solution, I will post and example file here soon.

Edited March 8, 2016 by cgBurns