pop advect stopping at bound

[logix1390]

Hello,

I have points that are being advected by my smoke sim. The problem is the points end up stopping where the bound of the smoke simulation ends. This obviously makes sense since there is no velocity beyond the bounding regions of the smoke sim. But how can I continue the velocity in a smart way beyond the bounds of the smoke sim? . I know that I can add extra forces to the particle network but that tends to make the whole simulation look different and it breaks up that nice advection. Any advice would be greatly appreciated.

I will attach my scene file for anyone that wants to take a look.

Thank you.

popadvect_stopping.hip

[garf]

On the popadvectbyvolume dop change "Advection Type" from Update Velocity to Update Force. This will give you a different advection but it will not be constrained to the bounding.

[evanrudefx]

Something else you can do is go to your smoke object go to initial data and change the border type. Repeat works well.

[logix1390]

@garf
Thanks but I already tried this. It technically works but it also loses a lot of the swirling detail that I was trying to achieve in the first place.

@ejr32123

Hmm.I set it to repeat, which repeats it from the bottom of my fluid container. I am not sure How I am supposed to apply this velocity to my particle sim. My actual scene has a very high resolution pyro sim that took a really long time to cache out. I am trying to advect points through this pyro sim without it getting stuck. If I use repeat , not only do I have to cache out my pyro sim again, it just repeats it from one end of the fluid container but the velocity still stays within the bounds. I am trying to extend the velocity outside of the bounds in some way. Maybe I am not applying this method correctly? Appreciate the help.

Thanks guys

[evanrudefx]

I don't have a lot of time to look at it now, but writing an expression to change velocity blend to 0 when it reaches the edge of the container seems to help.I will look at this more later, because I actually was wondering the same thing a few weeks ago.

[logix1390]

Thanks ejr. I tried to do exactly that by calculating the distance from the particles to the edge of a box which represents the bounding box of the pyro sim.

Then I remapped the distance attribute from 1-0 and remapped that to the velocity blend.

It did not work as expected but I feel like I'm moving in the right direction. Going to look at it tomorrow.

I'll attach my scene file to show you what I did. 

popadvect_stopping.hip

[logix1390]

anyone have any tips? doesnt seem to be working to well..

[evanrudefx]

check out this file. I only added the Y max, but you could add the rest of the sides of the container. Honestly this is the best I can do atm : ( It seems like it could function

popadvect_stopping_update.hiplc

Edited September 9, 2018 by ejr32123

[logix1390]

Hey ejr. Thank you, this works!. Definitely is a good starting point !Appreciate the help