Hi all -

I'm looking to make some bubbles in my FLIP fluid. My idea was to make a group that selects a few particles by id, then instance spheres on them as a starting point.

I've tried feeding the particles into a group geometry node. I can see the $ID attribute on the particles, and I'm trying to group by expression with $ID % 1000 == 0, or $ID > 1000, then going to a delete not selected.

For some reason, that doesn't seem to create a group - any ideas?

not sure why thats not working, but a better method might be to use a sop solver. put a grid at the bottom of your flip tank and then just scatter a few points on that grid, and copy spheres to them. then plug those spheres into the right side of a group node, to group points and change their density attribute. once you do it in a sop solver you really have the most control over everything.

That sounds like a good idea.

I've come to realize I was using DOP import to bring in my FLIP particles. DOP I/O brought it in with the ID attributes.

Looks like the particles sometimes die, and sometimes jump around, so I suspect your attribute idea is a better one - the bubbles in your reel are quite handsome

So - make a grid, scatter points on it, emit particles (in a POP?) from those points, attribute transfer velocity onto them? Any tips to get that nice warble I see in the bubbles in your reel? Any tips on that lovely refractive rendering - is that Mantra?

yeah simple mantra pbr with an hdr. for the sim itself though, you dont need to emit any particles at all. start with a flip tank. then plug the flip tank object into the left input of a multisolver, and plug the flip solver and and sop solver into the right input. inside the sopsolver make a grid, scatter points on it. these points will be the center of your bubbles. copy spheres to them the size you want your bubbles to start. group the flip points by the spheres and add them to a group called bubbles. then use an attribcreate, set the group to bubbles and then make the attribute density and set the value to something like 2. you only want these spheres to be here and there and only on a few frames, so maybe set up a switch and a null so your not making bubbles on every frame.

i cant open houdini right now or else id set up an example file for ya.. if your still having troubles i can probably do it later tonight though.

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=26602&highlight= [sidefx.com]

There's an example file on that page: http://www.sidefx.com/index2.php?option=com_forum&Itemid=172&page=download&id=11990 [sidefx.com]

hey, thanks guys!

And yes, if you'd be willing to setup a simple demo, that'd be fantastic.

ask if you have any questions.

Fantastic! Thank you!

np

Or maybe scene from old school

http://forums.odforce.net/index.php?/topic/15486-bubbles/page__hl__bubbles [forums.odforce.net]