How do you do variable density like in the flip demo?

On the source you can add point attribute called density and vary however you like. I usually use a vopsop for this. Then on the flip solver you have to enable the density from attributes under volume motion (I think this is where it is) If you need to then change it after it's been emitted you can use a sop solver.

The bubbles look really nice, thanks. I wish SESI would post a hip of all the stuff new in H12, it would make stuff more streamline.

They often add scenes to the example files… there's one for flip density / viscosity in there as well.
http://www.sidefx.com/docs/houdini12.0/nodes/dop/flipsolver [sidefx.com] check out the bottom of the page.

I keep wishing SESI would do stuff, and it turns out they've done it half the time. Thanks.

Sorry I put off checking the file for ages, turns out it's not what I'm after, how would you achieve the bubble affect?

Is the attached file something along the lines you're looking for?

Well sort off, how do you get the parts to be hollow, and than have little bubbles form (I think whitecaps will do the trick), all i need to know is the hollow part.

Delete them before you surface them. if density < 900, delete the particles, and they will appear as bubbles. Or, group them separately and instance spheres or geometry onto them… stuff like that. Gotta be creative. You could also delete them after they reach the top by checking to see if they are still ‘inside’ the high density ones – usually done by creating a volume from the high density particles.

Oh, for whatever reason it totally skipped my mind, but if you watch the waterfall tutorial, he shows some ways to do foam, where the particles float up to the surface, it can be easily adapted to make those particles bubbles instead of foam, not using the varying density of the sim itself.

Thanks, I ended up using color when trying to figure it out before your post, but density would be better.

Hello!
I'm following the FLIP Waterfall tutorial here (https://vimeo.com/39835049) [vimeo.com] and I'm trying to add bubbles like in the FLIP demo or in Solitude's scene above.. but the problem is that I'm trying to use some scattered points to do that..

I'm trying to add forces to the fluid using those points but I'm not sure where should I add the points.

Any pointer, advice?

thanks in advance.


edit: Well, it was pretty easy. I used the “Pump” from Populate Containers shelf and was working good but I decided to implement some random velocity and random emitters with the help of the Smoke in H12 [vimeo.com] video by Peter Quint

Yay!