Affecting flip particles by pop force by speed.

[Strob]

Hi,

 

I am playing witht that very cool example file from the doc: ( local doc only at the bottom of this page: http://127.0.0.1:48626/nodes/dop/popcurveforce )

It shows how to use a Curve Pop force to direct a flip fluid.

What I would like to do now is to use a turbulence force (there is already one in that example on the popforce1 node) to influence only the low speed particles.

How can I make a force to influence only the particules moving below a certain speed? And maybe with a little gradient from zero at that speed and becoming greater when the speed becomes lower? I think that would prevent the fastest one to get too much speed and leave the curve path.

I got the idea from this example where "Myke" is saying in the comments that he used a turbulence force to influence only the slow particles.: 

 

Edited May 22, 2017 by Strob

[Farmfield]

Myke is Myke Mendes.

And I did this quick setup recently, just to illustrate how much more controllable it is just doing a custom force for something like this, you really have absolute control whereas using the curve force, one force of the setup can make another behave very differently just doing small changes - I'd rather have that control creating the force "manually".

And yes, this is shamefully simplistic, but it's just to demonstrate how simple it is to set something like this up.

https://drive.google.com/open?id=0B6IjWrRnlE0dazdCay1NeVBVNWs

[Farmfield]

Oh, as for the question, you'd just use a POP wind and tick the VEXpressions thingie and use something like

amp *= (length(@v) < XX ) ? ZZ : YY ;

Where XX is the speed limit, the ZZ the multiplier of true and YY the multiplier when false.

And the above is short form for this:

if(length(@v) < XX ){
    amp *= ZZ ;
}else{
    amp *= YY ;
}

And you can use a POP wrangle and create an attribute for particle speed which makes it simpler to check the spreadsheet for where the speed lies, easier to find the sweet spot for the limiter than using trial and error, perhaps.

Edited May 23, 2017 by Farmfield

[Strob]

Hi Farmfield! Very cool! Thank you so much, I'll check this out tomorrow!