Hi guys,

I've created a popnet + source node and spawn a certain amount
of particles only on frame 1 inside the volume of a tube object.
Where can I control the position seed of the born particles?
Can't find the parameter

regards,

Manuel

Edit:
I know about a solution creating a points from volume SOP before the popnet and use those points as born position, but it would be nice to know if there's another way inside the PopNet

there is Random Seed parameter directly on POP Network node

haha just found it in the same minute you wrote me
thanks anyways hehe

sometimes it is a good idea to scatter points, and use them as source, so You have exact control.

EDIT: ha, missed Your last edit :roll:

ok, one question leads to the next:

Is it possible to randomly distribute points in a volume but with a certain space between each other? For example one could say each born particle should have a minimum distance to the next nearest point.

I tried using the scatter SOP and calculate the nearest distance and then delete points by their ptarea attribute but didn't get satisfying results.

I think this is a feature one could use every so often so it wouldn't be a bad idea to implement it into the points from volume SOP or the scatter SOP ?!

regards

Manu

have you tried Points From Volume SOP?

Yes, I have already tried that one, and as I said, the results aren't that satisfying. Isn't there another way?

Also, I have tried to do this whole “find and delete nearest point based on threshold” thing on my own in VOPs and have a few questions
I used a forloop for this purpose. I run each point through the loop and find it's nearst point depending on a distance value that is compared to a threshold parameter. Then the nearest points get sent into a group and are being deleted in the next kill node.

First question: My loop goes infinite and does a new calculation every new frame and after some frames all particles are gone, there's something wrong. I corrected this with the activation parameter of the voppop itsself,
but that's only makeshift solution.

Second. As you will notice, points get deleted, but some are still very very colose together which doesn't make much sense to me.

Thanks for helping me in my studies,
regards

you can use Interact POP for that effect and forget all kill nearest approach

because if one particle is closer to another than the treshold then both will be deleted so you will get large empty areas
the solution to that approach would be ForEach SOP where each time you will process only one point and compare its position only to closest point which is not in delete group. Then add it to delete group if within treshold.

but as I said Interact POP will distribute points evenly after when you play the simulation. Look at the file. There is a switch between planar and volume points

ok thanks for that example, it's very helpful!