Jump to content

POP Streams Questions

Recommended Posts


I've watched https://www.sidefx.com/tutorials/particle-streams-1/ by Peter Quint on Streams, and I have the following questions:

-Streams are just a way to describe particle "states"? In the tutorial above, they are placed only at the top of different chains and then merged and connected to a POP Solver

-What's the use of the input connection of the Stream node, either way somehow it has access to the entire Particles in the DOP network?

-POP Group and POP Stream nodes have very similar interfaces, what makes them different? The only difference I can find is that the output connection of a Stream is those particles that are in this Stream, whereas the output connection of a Group is still the entire input particles?

-The order in which we when we merge multiple streams into POP Solver matters? Meaning, the POP Solver will execute the Streams branches in the same order it's fed in?



Link to comment
Share on other sites

Streams are essentially a convenience method. You could set up a group and then apply a following series of nodes to that group by setting the group parameter on each node and have the same effect as the stream. The stream is neater, that's all.

One use is as a state system, as the tutorial shows, but there are other uses. 

If I remember right the input comes into its own when you have more than one emitter in the sim. 

Yes the order of connection to the merge node does effect the order of execution. So if a particle is in two streams the ordering can have a significant impact. 


  • Like 1
Link to comment
Share on other sites

Wow, I was not excepting Peter to reply :) Thanks Peter for taking the time to reply. Sorry for the poorly written questions, I guess I was super tired when I wrote them :)

The dependency of execution on the order of connections is a little bit "strange" in my opinion, I "think" there should be other ways to make results less sensitiveness to order. Maybe using "Streams" as states make it look that way, because if a particle in a state, then its next state should be the same regardless of the order of execution. On a second thought, I guess it depends on how one designs his/her network, i.e. if transitions are independent then we should not have this order of connection dependency issue... 

Once more, thanks for your reply :)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...