Enabling a force for only particles with this attribute

[HolesinShoes]

Hi all!

I'm using a FLIP fluid, with a pop curve force to guide them, which is working well. However, I want to make the particles only have gravity after they've left the curve. To do this, I would expect to be able to use the "oncurve" attribute created by the pop curve force, but the following VExpression is not working:

force = @oncurve == 1 ? force : 0;

This was suggested to me by a user on another forum, however if this can also be done with standard expressions (such as on the activation parameter), then I'd be more than happy to hear it.

Any help is greatly appreciated!

Edited December 18, 2018 by HolesinShoes

[Sepu]

use a pop stream to see what particles are affected.

ingroup = @oncurve == 0;

then you can apply a pop force or whatever forces you want to apply to those particles downstream, and merge it to the mainstream.

[HolesinShoes]

Thanks Sepu, problem solved!

I've got another hopefully quick question:

is it possible to restrict whitewater emmission to particles with an oncurve attribute of 0?

[Sepu]

Yes you should be able either with a popwrangle or popvop, have a look at the docs the whitewater solver change in 17  http://www.sidefx.com/docs/houdini/nodes/dop/whitewatersolver.html

[HolesinShoes]

Can it be done in 16? I still haven't downloaded 17

[HolesinShoes]

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