Jump to content

Kill particles after specified time after collision


Recommended Posts


I'm novice to houdini and I'd like to have particles killed after some time elapsed after collision happened. What would be the correct approach? Should I try to do it with events? Or can it be done with Kill POP using VEXpression rule?



Link to comment
Share on other sites

You can use pop kill and pop collision detect.

Collision will create hitnum and hittime attribute.


dead = i@hitnum > 1 & @age - @hittime > 1;


The hittime will be 0 if collision not happen.

You must use if condition 


It will delete the particle 1 second after collision.

Hope it help.

Edited by wateryfield
Link to comment
Share on other sites

Hi, thank you for your response.

I noticed that popsolver already created attributes hitnum and hittime. However when I am checking those attributes in details view for certain particle, then on time when collision happens hitnum is set to 1 but next frame it is 0 again. And the hittime seems to behave strangely. It increments only after some frames and sometimes even decreases. To detect whether collision occured maybe I can check whether hitpos is not zero.

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...